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Simple Summary: Insecticides and augmentative biological control employing the inundative release of natural enemies are strategies to obtain a rapid reduction in pest populations. Regardless of insecticide selectivity, the dominant outcome is the incompatibility between these two control approaches. The majority of natural enemies are also susceptible to insecticides, and a physiologically selective insecticide may feasibly integrate both methods. Resistant natural enemies are those that were once susceptible but have acquired physiological changes that confer resistance to insecticides analogous to pest species under insecticide pressure. As a result, natural enemies that are selected for resistance to common nonselective insecticides fall under the category of physiological selectivity. Insecticides from the pyrethroids group are primarily recommended for managing defoliating insect pest species, whereas the ladybird beetle Coccinellinae predominantly preys on aphids. This means that they control distinct pest categories in the agroecosystem. Reports also state that pyrethroid treatments cause outbreaks of sucking insect pests like aphids, whiteflies, and psyllids because they negatively impact their natural enemies, with a small impact on the sucking insect pest species. The presence of pyrethroid-resistant ladybird beetles is essential for integrating these two control methods. The conservation of the predatory ladybird beetle, Eriopis connexa (Germar) after its release also relies on its resistance and the performance of its progenies. When resistant individuals are released or evolve in the field through mating with susceptible pairs, we anticipate that they will generate a resistant progeny, inheriting the resistance to lambda-cyhalothrin through an autosomal mechanism. The susceptibility of a field-collected population (EcGA) was characterized and determined by the performance of their progenies generated through mating with a resistant parent (EcViR). We paired virgin adults from the EcGA and EcViR populations, observing how their progenies developed, reproduced, and survived when exposed to dried lambda-cyhalothrin residues applied at field rates. Adults from the EcGA population were ~200-fold more susceptible than those of the EcViR population. Developmental times from larva to adult emergence for EcGA individuals were delayed by approximately 6 days and generated smaller adults compared to EcViR and their progenies. The egg production did not differ across parents and progenies, but females from EcGA and EcGA × EcViR progenies produced 130 more eggs in comparison to EcViR females during the 35-day evaluation period. Exposure to lambda-cyhalothrin resulted in 77.4 to 100% survival for adults from EcViR × EcGA progenies and EcViR parents, while EcGA and the population standard for susceptibility maintained in the laboratory (EcFM) did not survive the insecticide exposure. These findings indicate that field crosses between EcViR and EcGA will improve their progenies' biological performance compared to the EcViR parents and will maintain a high lambda-cyhalothrin survival rate. [ABSTRACT FROM AUTHOR]

Simple Summary: Tomato yellow leaf curl virus (TYLCV) poses a serious constraint to tomato production in the Southeastern United States. Since its introduction, it has become endemic in states such as Georgia and Florida despite tomato-free periods. This study examined whether the endemic status of TYLCV is aided by the Bemisia tabaci B cryptic species' vertical and/or horizontal non-feeding modes of TYLCV (the Georgia variant of the Israel strain) transmission. The potential for 'non-feeding' transmission modes has been examined previously, with inconsistent results. The objective of this study was to determine the frequency of TYLCV transovarial and/or sexual (mating) transmission and the subsequent transmissibility of the virus to virus-free plants. The study utilized a series of virus transmission assays and detection and quantitation tools. Our results indicate that non-feeding transmission modes are a rare phenomenon in this pathosystem, and their significance is irrelevant for the observed endemic status of TYLCV in the southeastern United States. Tomato yellow leaf curl virus (TYLCV) causes significant yield loss in tomato production in the southeastern United States and elsewhere. TYLCV is transmitted by the whitefly Bemisia tabaci cryptic species in a persistent, circulative, and non-propagative manner. Unexpectedly, transovarial and sexual transmission of TYLCV has been reported for one strain from Israel. In this study, the potential contribution of the B. tabaci B cryptic species transovarial and sexual transmission of TYLCV (Israel strain, Georgia variant, Georgia, USA) to reoccurring outbreaks was investigated by conducting whitefly-TYLCV transmission assays and virus DNA detection using end point PCR, DNA quantitation via real-time PCR, and virion detection by immunocapture PCR. TYLCV DNA was detectable in four, two, and two percent of first-generation fourth-instar nymphs, first-generation adults, and second-generation adults, respectively, following transovarial acquisition. Post-mating between viruliferous counterparts, the virus's DNA was detected in four percent of males and undetectable in females. The accumulation of TYLCV DNA in whiteflies from the transovarial and/or sexual experiments was substantially lower (100 to 1000-fold) compared with whitefly adults allowed a 48-hr acquisition-access period on plants infected with TYLCV. Despite the detection of TYLCV DNA in whiteflies from the transovarial and/or mating experiments, the virions were undetectable by immunocapture PCR—a technique specifically designed to detect virions. Furthermore, tomato test plants exposed to whitefly adults that presumably acquired TYLCV transovarially or through mating remained free of detectable TYLCV DNA. Collectively, the extremely low levels of TYLCV DNA and complete absence of virions detected in whiteflies and the inability of the B. tabaci cryptic species B to transmit TYLCV to test tomato plants following transovarial and mating acquisition indicate that neither transovarial nor sexual transmission of TYLCV are probable or epidemiologically relevant for TYLCV persistence in this pathosystem. [ABSTRACT FROM AUTHOR]

Simple Summary: The sweet potato whitefly is a major global pest in vegetable production. The management of this pest has typically relied heavily on insecticide treatments. Many populations of sweet potato whitefly are now resistant to insecticides. Therefore, alternative means to control this pest are needed. Many predatory insects consume sweet potato whiteflies, so helping lure and attract both predators and the pest to the same location could improve control. This study investigates attractive odors for sweet potato whiteflies and two predator species that could be used to improve sweet potato whitefly pest management. Traditionally, olfaction was thought to play a minor role in the behavioral ecology of the sweet potato whitefly, Bemisia tabaci (Gennadius). However, recent research is uncovering significant potential for whitefly management based on olfaction. Incorporating chemical attractants with standard whitefly management programs could significantly improve control. The integration of attractants with biological control is exceptionally promising. Therefore, the behavioral response of B. tabaci and two generalist predators to the green leaf volatiles (E)-2-hexenal, (Z)-3-hexenal, (Z)-3-hexenyl acetate, and (Z)-3-hexe-1-ol were investigated in Y-tube olfactometers. Three of the four green leaf volatiles resulted in the attraction of female B. tabaci. Blend optimization indicated a two-chemical blend to be the most attractive blend for female B. tabaci. In addition, this blend was attractive to female Macrolophus praeclarus (Distant) but did not elicit a behavioral response from either male or female Delphastus catalinae (Horn). The two-chemical blend of green leaf volatiles could be further developed as a lure to attract B. tabaci and its predator, M. praeclarus. [ABSTRACT FROM AUTHOR]

Simple Summary: The predatory insects Macrolophus pygmaeus Ramber (Heteroptera: Miridae) and Nesidiocoris tenuis Reuter (Heteroptera: Miridae) are important biological control agents used commercially for the control of main pests in greenhouses, such as Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) and whiteflies (Homoptera: Aleyrodidae). In this study, we investigated the predation efficacy of young and old females and males of the two mirid bugs, M. pygmaeus and N. tenuis, when feeding on eggs of T. absoluta on tomato leaves. Young females of M. pygmaeus exhibited a higher predation efficiency compared to old ones, whereas males displayed a consistently low efficiency of predation irrespective of their age. Both young females and males of N. tenuis displayed a similarly high predation efficiency, although the old females exhibited a higher efficiency of predation compared to their male counterparts, but lower than the efficacy of the M. pygmaeus individuals. Our findings indicate that the two predatory species have different functional response characteristics to their prey depending mainly on their sex and age which may influence their efficacy as biological control agents. The predatory mirids Macrolophus pygmaeus Ramber (Heteroptera: Miridae) and Nesidiocoris tenuis Reuter (Heteroptera: Miridae) are used for the biological control of Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) and other pests in tomato greenhouses. The functional response of 1-day-old (young) and 10-day-old (old) adult females and males of M. pygmaeus and N. tenuis on eggs of T. absoluta was determined on tomato at two temperatures (20 °C and 25 °C) and LD 16:8. Females of M. pygmaeus exhibited higher predation efficiency than males at both tested temperatures. Young M. pygmaeus females had a higher efficiency than old ones, whereas males had a low efficiency irrespective of age. The predation efficiency of N. tenuis was high (but lower than M. pygmaeus) in both young females and males, although old females had a higher efficiency than the respective males. Our results show that the two predatory species have different functional response characteristics to their prey depending mainly on sex and age, which may affect their role as biological control agents. [ABSTRACT FROM AUTHOR]

Simple Summary: In agriculture, managing pests like the sweetpotato whitefly, Bemisia tabaci MEAM1, which can severely affect the development and yield of vegetable crops, is crucial. This study explored different insecticide rotations to control this pest on tomato plants. We compared standard synthetic insecticide rotations with biopesticide rotations including biochemical and microbial products alone or combined. Our trials, conducted in the spring and fall of 2023, examined how different insecticide rotations impacted the number of whiteflies. The results showed that while traditional synthetic insecticides consistently reduced the whitefly numbers, biopesticides also provided whitefly control to a lower extent. Overall, although a standard synthetic insecticide rotation adopted in Florida to manage B. tabaci MEAM1 was very effective, microbial biopesticides could become an option to reduce the use of synthetic insecticides and potentially mitigate the risk resistance development. These findings offer farmers new options to manage whiteflies effectively while also considering environmental sustainability. In summary, this research contributes to the ongoing efforts in agriculture to balance effective pest control with the need to protect the environment and reduce chemical usage. The sweetpotato whitefly, Bemisia tabaci MEAM1, is a pest known to significantly impact tomato development and yields through direct damage and virus transmission. To manage this pest, the current study compared the effectiveness of various insecticide rotations. Field trials included rotations involving synthetic insecticides, biochemicals, and microbial agents, applied according to their highest labeled concentrations. The results indicated that while standard synthetic insecticides consistently reduced whitefly egg and nymph counts significantly, microbial biopesticide rotations also achieved reductions, although less consistently. This study demonstrated that while traditional chemical treatments remain highly effective, microbial biopesticides containing Beauveria bassiana and Cordyceps javanica present a viable alternative to manage MEAM1 in tomato fields. The data generated in this study provided baseline information for further investigations to determine the potential for optimizing integrated pest management (IPM) and insecticide resistance management (IRM) strategies by incorporating microbial biopesticides in rotations with a variety of modes of action to sustainably manage B. tabaci MEAM1 populations in agricultural settings. [ABSTRACT FROM AUTHOR]

Simple Summary: As an invasive pest, whitefly causes great losses in agricultural production, and resistance increases in whitefly to chemical insecticides are an important problem in plant protection. Our study revealed that imidacloprid stress inhibits the expression of AKH, thereby increasing ROS and the expression levels of the resistance gene CYP6CM1 and upstream regulatory factors in Bemisia tabaci. AKH silencing by RNA interference affected the resistance of whiteflies to imidacloprid. These results provide insight into the resistance mechanism in whitefly. Synthetic insecticides used to control Bemisia tabaci include organophosphorus, pyrethroids, insect growth regulators, nicotinoids, and neonicotinoids. Among these, neonicotinoids have been used continuously, which has led to the emergence of high-level resistance to this class of chemical insecticides in the whitefly, making whitefly management difficult. The adipokinetic hormone gene (AKH) and reactive oxygen species (ROS) play roles in the development of insect resistance. Therefore, the roles of AKH and ROS in imidacloprid resistance in Bemisia tabaci Mediterranean (MED; formerly biotype Q) were evaluated in this study. The expression level of AKH in resistant B. tabaci MED was significantly lower than that in sensitive B. tabaci (MED) (p < 0.05). AKH expression showed a decreasing trend. After AKH silencing by RNAi, we found that ROS levels as well as the expression levels of the resistance gene CYP6CM1 and its upstream regulatory factors CREB, ERK, and P38 increased significantly (p < 0.05); additionally, whitefly resistance to imidacloprid increased and mortality decreased (p < 0.001). These results suggest that AKH regulates the expression of resistance genes via ROS in Bemisia tabaci. [ABSTRACT FROM AUTHOR]

Simple Summary: The present study explores the impact of alternative prey on predator–prey dynamics in two contexts, without and with intraguild predation (IGP). It was found that without IGP, G. punctipes displayed a generalized functional response regardless of the alternative prey. However, under IGP conditions, the predator's functional response shifted to Type II, but the alternative prey did affect this response and it turned to a generalized type. In both contexts, handling times increased and consumption of the focal prey decreased as the density of the alternative prey increased. The presence of parasitized whitefly nymphs notably affected predator–prey dynamics, probably due to changes in prey characteristics. In biological control, joint releases of predators and parasitoids are standard. However, intraguild predation (IGP) can occur when a predator attacks a parasitoid, potentially affecting pest control dynamics. In addition to the focal prey (FP), Trialeurodes vaporariorum, the intraguild predator (IG-predator) Geocoris punctipes can consume the parasitoid Eretmocerus eremicus (IG-prey). In this IGP context with multiple prey, an alternative prey (AP), like the aphid Myzus persicae, may influence interactions. Theory predicts that, in simple interactions, a predator's functional response (FR) to the FP changes with the presence of an AP. However, whether this holds in an IGP context is unknown. In this study, we empirically tested that prediction. Our results show that without IGP, G. punctipes exhibits a generalized FR with and without AP. Nevertheless, with IGP, the predator exhibited a Type II FR at low and high AP densities, increasing pressure on the FP and potentially favoring short-term biological control strategies. However, when 25 AP were offered, the predator's response shifted, underscoring the importance of monitoring AP densities to prevent potential disruptions in FP control. In both contexts, the increase in AP produced a handling time increase and a decrease in consumption rate. These results indicate that the theoretical prediction of the effect of AP on the FR is met only under specific conditions, and the complexity of multitrophic interactions must be considered. [ABSTRACT FROM AUTHOR]

Simple Summary: As whiteflies, Bemisia tabaci (Genn.), are continually developing resistance to conventional insecticides, it is crucial and pressing to seek new approaches to management. In this study, the synergistic effect of lemongrass essential oil and flometoquin, flonicamid, and sulfoxaflor on B. tabaci was studied. Based on the found LC values, the decreasing order of toxicity to B. tabaci was as follows: sulfoxaflor > flonicamid > flometoquin > lemongrass EO. Sulfoxaflor and flonicamid exhibited significant inhibition of AchE activity, while only flonicamid demonstrated a significant impact on α-esterase. However, none of the tested compounds affected cytochrome P450 or GST. Additionally, lemongrass EO and the tested insecticides exhibited significant binding affinity to AchE. The whitefly, Bemisia tabaci (Genn.), is one of the most dangerous polyphagous pests in the world. Eco-friendly compounds and new chemical insecticides have gained recognition for whitefly control. In this study, the toxicity and biochemical impact of flometoquin, flonicamid, and sulfoxaflor, alone or combined with lemongrass essential oil (EO), against B. tabaci was studied. In addition, a molecular docking study was conducted to assess the binding affinity of the tested compounds to AchE. Based on the LC values, the descending order of the toxicity of the tested compounds to B. tabaci adults was as follows: sulfoxaflor > flonicamid > flometoquin > lemongrass EO. The binary mixtures of each of the tested compounds with lemongrass EO exhibited synergism in all combinations, with observed mortalities ranging from 15.09 to 22.94% higher than expected for an additive effect. Sulfoxaflor and flonicamid, alone or in combination with lemongrass EO, significantly inhibited AchE activity while only flonicamid demonstrated a significant impact on α-esterase, and none of the tested compounds affected cytochrome P450 or GST. However, the specific activity of P450 was significantly inhibited by the lemongrass/sulfoxaflor mixture while α-esterase activity was significantly inhibited by the lemongrass/flometoquin mixture. Moreover, the lemongrass EO and all the tested insecticides exhibited significant binding affinity to AchE with energy scores ranging from −4.69 to −7.06 kcal/mol. The current findings provide a foundation for utilizing combinations of essential oils and insecticides in the integrated pest management (IPM) of B. tabaci. [ABSTRACT FROM AUTHOR]

Simple Summary: Whitefly is one of the most devastating pests of cassava among smallholder farmers in East and Central Africa. The pest causes severe damage to plants through direct feeding as well as spreading the deadly cassava mosaic disease and cassava brown streak disease. Most of the improved cassava varieties in Uganda were developed for cassava mosaic disease resistance and cassava brown streak disease tolerance. Moreover, few research efforts have focused on ascertaining their reaction to whitefly infestation. A research study was therefore conducted to determine the reaction of several improved regional cassava varieties in a bid to identify those with resistance to whitefly in Uganda. The results reveal that cassava variety Mkumba consistently supports low whitefly populations across all locations. The findings of this study further indicate the potential of improved cassava varieties for the effective and sustainable management of whitefly, especially in the high-pest-pressure areas of Uganda and the continent at large. Cassava whitefly, Bemisia tabaci, directly damages cassava leaves by feeding on phloem, causing chlorosis and abscission, leading to a yield loss of up to 50%. The pest also causes indirect damage through sooty mold formation. Most Ugandan cassava varieties resist cassava mosaic disease (CMD) and tolerate cassava brown streak disease (CBSD), but little is known about their response to whitefly infestation. The main objective of this study was to identify cassava genotypes with putative resistance to whitefly in Uganda. This was conducted on 24 improved cassava varieties in three agro-ecological zones during the second rains of 2016. Monthly data were taken for adult and nymph counts, whitefly and sooty mold damage, and CMD and CBSD severities from 2 to 9 months after planting (MAPs). The results show that the whitefly population is highly significantly (p < 0.000) amongst varieties across the three agro-ecological zones. Mkumba consistently supported the low adult numbers and nymphs. The findings demonstrate the potential of the improved cassava varieties as sources of whitefly resistance for sustainable management. [ABSTRACT FROM AUTHOR]

Simple Summary: Cabbage whitefly (Aleyrodes proletella) is a destructive sucking insect pest of brassica crops, particularly white cabbage and kale. Its importance has been increased over the last decade in many geographic regions, particularly in European countries. The control of cabbage whiteflies largely relies on the application of synthetic insecticides to protect yield if populations reach economic damage thresholds. One class of insecticides to control this pest are cyclic ketoenols targeting acetyl-CoA carboxylase (ACC), an enzyme involved in fatty acid biosynthesis. In 2019, reduced efficacy of ketoenol insecticides at recommended label rates were reported. Subsequently, we collected field samples of A. proletella in different European countries and confirmed the presence of ketoenol resistance in laboratory bioassays. The resistance allele was shown to be an autosomal dominant trait in crossing experiments between susceptible and resistant individuals. RNA sequencing and subsequent analysis revealed a mutation, an amino acid substitution, at the ketoenol binding site in ACC. The mutation has been previously functionally validated to confer high levels of ketoenol insecticide resistance in cotton whiteflies, too. A molecular screening of 49 populations revealed the presence of the mutations in several countries. We recommend the implementation of resistance management strategies for sustainable cabbage whitefly control. Cabbage whitefly, Aleyrodes proletella L., is an invasive hemipteran pest of cruciferous plants, particularly field brassica crops. Its importance has been increased over the last decade, particularly in European countries. The control of cabbage whiteflies largely relies on the application of synthetic insecticides, including tetronic and tetramic acid derivatives such as spiromesifen and spirotetramat (cyclic ketoenol insecticides), acting as insect growth regulators targeting acetyl-CoA carboxylase (ACC). In 2019, reduced efficacy against cabbage whiteflies of ketoenol insecticides at recommended label rates has been reported. Subsequently we collected field samples of A. proletella in different European countries and confirmed the presence of ketoenol resistance in laboratory bioassays. Reciprocal crossing experiments revealed an autosomal dominant trait, i.e., heterozygotes express a fully resistant phenotype. Transcriptome sequencing and assembly of ACC variants from resistant strains revealed the presence of an ACC target-site mutation, A2083V, as previously described and functionally validated in Bemisia tabaci (A2084V in A. proletella). Next, we employed a molecular genotyping assay to investigate the geographic spread of resistance and analyzed 49 populations collected in eight European countries. Resistance allele frequency was highest in the Netherlands, followed by Germany. Finally, we provide a proposal for the implementation of appropriate resistance management strategies. [ABSTRACT FROM AUTHOR]

Simple Summary: Invasive alien species are a major element of global change and represent a threat to global biodiversity and ecosystem integrity. Early detection of invasive species is of capital importance for management success. We describe the process by which the invasive whitefly, Aleurocanthus spiniferus (Hemiptera, Aleyrodidae), listed as a European quarantine organism, was detected in France. The first observation was made by a volunteer who reported a picture of an adult Aleurocanthus spiniferus on the Inventaire National du Patrimoine Naturel (INPN Espèces), a citizen science resource developed by l'Office Français de la Biodiversité and the French Muséum National d'Histoire Naturelle. We outline the sequence of actions that led to the official reporting of this species in France and show how incursion preparedness contributed to a rapid response. This case exemplifies how citizen science can contribute to the early detection of invasive species and highlights the importance of informing both the general public and professionals about major environmental issues. We describe the process by which the quarantine whitefly, Aleurocanthus spiniferus (Hemiptera, Aleyrodidae), was detected in France. The initial observation was made by a volunteer who reported a picture of an adult in the Inventaire National du Patrimoine Naturel (INPN Espèces), a citizen science resource developed by l'Office Français de la Biodiversité and the French Muséum National d'Histoire Naturelle. The specimen was suspected to be A. spiniferus from this picture by one of the expert entomologists in charge of the Hemiptera group validation. Once the species was identified, it was mounted on a slide and the information was officially passed on to the ministry in charge of agriculture via a communication channel set up in advance for this type of situation. The ministry then triggered the regulatory actions planned in the event of the suspected detection of quarantine organisms. Sampling was quickly carried out and the specimens collected on this occasion were formally identified as belonging to the species A. spiniferus. This led to the formalization of an outbreak in France. This sequence of decisions took just two months from the first observation to the implementation of a management plan. This case presents how incursion preparedness contributes to a rapid response. Furthermore, this case exemplifies how citizen science can contribute to the early detection of invasive species and highlights the importance of informing both the general public and professionals about major environmental issues. [ABSTRACT FROM AUTHOR]

Simple Summary: Many obligate endosymbionts colonize an invertebrate host and are directly transferred maternally to the host's embryo. Consequently, the symbiotic bacteria from diverse host species evolve independently, reflecting the host's phylogeny. Whiteflies, which consist of thousands of species, harbor obligate endosymbionts of the Portiera genus. The divergence status of these bacteria, after a long history of coevolution with their hosts, remains ambiguous. In the present study, we aim to unravel the divergence of obligate endosymbionts from different whitefly species through genome comparison. Our findings indicate that these endosymbionts have diverged into at least three disparate genetic groups. Such findings underscore the divergence of whitefly obligate endosymbionts and provide a cue for investigation into the co-divergence between obligate endosymbionts and their hosts. Maternally inherited obligate endosymbionts codiverge with their invertebrate hosts and reflect their host's evolutionary history. Whiteflies (Hemiptera: Aleyrodidae) harbor one obligate endosymbiont, Candidatus Portiera aleyrodidarum (hereafter Portiera). Portiera was anciently acquired by whitefly and has been coevolving with its host ever since. Uncovering the divergence of endosymbionts provides a fundamental basis for inspecting the coevolutionary processes between the bacteria and their hosts. To illustrate the divergence of Portiera lineages across different whitefly species, we sequenced the Portiera genome from Aleyrodes shizuokensis and conducted a comparative analysis on the basic features and gene evolution with bacterial genomes from five whitefly genera, namely Aleurodicus, Aleyrodes, Bemisia, Pealius, and Trialeurodes. The results indicated that Portiera from Bemisia possessed significantly larger genomes, fewer coding sequences (CDSs), and a lower coding density. Their gene arrangement differed notably from those of other genera. The phylogeny of the nine Portiera lineages resembled that of their hosts. Moreover, the lineages were classified into three distinct genetic groups based on the genetic distance, one from Aleurodicus (Aleurodicinae), one from Bemisia (Aleyrodinae), and another from Aleyrodes, Pealius, and Trialeurrodes (Aleyrodinae). Synonymous and nonsynonymous rate analyses, parity rule 2 plot analyses, neutrality plot analyses, and effective number of codons analyses supported the distinction of the three genetic groups. Our results indicated that Portiera from distant hosts exhibit distinct genomic contents, implying codivergence between hosts and their endosymbionts. This work will enhance our understanding of coevolution between hosts and their endosymbionts. [ABSTRACT FROM AUTHOR]

Simple Summary: Sweet potato whitefly is a major pest in zucchini production due to the direct and indirect damage it causes to this crop. The present study evaluated reflective silver plastic mulch and an insect row cover as alternative methods to manage whiteflies in zucchini production in the southeastern U.S. Field experiments indicated reduced whitefly numbers under reflective silver plastic mulching and insect row cover treatments. These methods also improved plant growth and yield compared to conventional white plastic mulch and no-cover treatments. In conclusion, these alternative methods can be considered ready-to-use integrated pest management practices for growers. The challenges that sweet potato whitefly (Bemisia tabaci) creates for vegetable production have increased in the southeastern U.S. Growers must use intensive insecticide spray programs to suppress extremely high populations during the fall growing season. Thus, the objective of this study was to evaluate the use of a reflective plastic mulch and an insect row cover as alternative methods to the current grower practices to manage whiteflies in zucchini (Cucurbita pepo) production. Field experiments were conducted with a two-level factorial experimental design of cover and plastic mulch treatments arranged in a randomized complete block design, with four replications in Georgia in 2020 and 2021, and in Alabama in 2021. Cover treatments consisted of an insect row cover installed on zucchini beds at transplanting and removed at flowering and a no-cover treatment, while plastic mulch treatments consisted of reflective silver plastic mulching and white plastic mulching. During all growing seasons, weather conditions were monitored, whitefly populations were sampled weekly, zucchini biomass accumulation was measured at five stages of crop development, and fruit yield was determined at harvesting. Warm and dry weather conditions early in the growing season resulted in increased whitefly populations, regardless of location and year. In general, the reflective silver plastic mulching reduced whitefly populations compared to the conventional white plastic by 87% in Georgia in 2020, 33% in Georgia in 2021, and 30% in Alabama in 2021. The insect row cover treatment reduced whitefly populations to zero until its removal. Consequently, zucchini plants grown with the insect row cover and reflective silver plastic mulching had an increased rate of biomass accumulation due to the lower insect pressure in all locations. Zucchini grown using silver reflective plastic mulch and row covers had an overall increase of 17% and 14% in total yield compared to white plastic mulch and no-cover treatments, respectively. Significant differences in yield among locations were likely due to severe whitefly pressure early in the fall season, and total yields in Georgia in 2020 (11,451 kg ha−1) were 25% lower than in Georgia in 2021 (15,177 kg ha−1) and in Alabama in 2021 (15,248 kg ha−1). In conclusion, silver plastic mulching and row covers reduced the whitefly population and increased biomass accumulation and total yield. These treatments can be considered ready-to-use integrated pest management practices for growers. [ABSTRACT FROM AUTHOR]

Simple Summary: The orange spiny whitefly, Aleurocanthus spiniferus, has invaded Greece and expanded its distribution in other countries in the European Union since 2008. It is a polyphagous pest that includes several highly important crop plants, such as citrus. Damage symptoms and effects on plants are identical to those of the citrus blackfly, Aleurocanthus woglumi (both Hemiptera: Aleyrodidae). The species also share a complex of natural enemies that were successfully introduced to Hawaii during 1974–1998. A short expedition to the islands of Oahu, Hawaii, and Kauai was conducted to retrieve the prominent natural enemies for introduction into Greece. Hawaii was chosen because it does not have citrus diseases and because of the existence of connections to facilitate research and export permits. Infested leaves were shipped to a quarantine facility in Greece for parasitoid emergence and evaluation. The identity of emerged parasitoids and host testing on the orange-spiny whitefly Greece strain were conducted. Only one parasitoid was abundant, characterized using molecular analysis as Encarsis perplexa. A summary of infestation records, parasitism rates, and localities on the Hawaiian Islands has been reported here for the first time since the release of parasitoids. Results showed that the infestations of citrus trees were minimal on the islands of Hawaii and Oahu, primarily on pummelo and sweet orange. Citrus whiteflies were not detected on the island of Kauai during this survey. E. perplexa had parasitism rates ranging from 0 to 28% on the island of Hawaii and 11 to 65% on the island of Oahu. A starter colony of the parasitoids has been colonized in the Greece Quarantine Facility for evaluation. This was the first field survey of Hawaii since the introduction and release of citrus whitefly natural enemies. Further surveys should be repeated in different countries to eliminate the risk of disease introduction. Whitefly species of Aleurocanthus spiniferus (Quaintance) and A. woglumi Ashby (Hemiptera: Aleyrodidae) are serious pests of citrus and other important fruit crops. The problem of citrus has initiated the successful introduction of several natural enemies for biocontrol programs in Hawaii and many other countries. Here, we summarized the history of infestation and biocontrol efforts of the two whiteflies in Hawaii for possible parasitoid importation into Greece. Two Platygasteridae (Amitus hesperidum Silvestri, A. spiniferus (Brethes), and three Aphelinidae (Encarsia clypealis (Silvestri), E. smithi (Silvestri), E. perplexa Huang, and Polaszek) were released in Hawaii for biocontrol of the citrus whiteflies during the period 1974–1999. The aphelinid Cales noacki Howard, purposely released for Aleurothrixus flococcus (Maskell) in 1982, was also reported to attack other whiteflies, including Aleurocanthus species, on citrus. An additional aphelinid parasitoid, Encarsia nipponica Silvestri, native to Japan and China, was accidentally introduced and found to attack both citrus whiteflies on the islands. Since the colonization of introduced parasitoids in infested fields on four Hawaiian Islands, no survey has been conducted to evaluate their potential impact. We conducted two short surveys during September–November 2022 on the islands of Kauai, Hawaii, and Oahu to introduce the dominant parasitoids to Greece for the biocontrol of A. spiniferus. Results showed that the infestation level was very low on Kauai, Hawaii, and Oahu Islands, with a mean infestation level range of 1.4–3.1 on Hawaii and Oahu Islands, mostly on pummelo and sweet orange, with no detection on the island of Kauai. The dominant parasitoid was characterized as Encarsia perplexa, using molecular analysis. Its parasitism rates ranged from 0 to 28% on the island of Hawaii and 11 to 65% on the island of Oahu. Emerged parasitoids have been reared in Greece for evaluation. This was the first field survey of Hawaii since the introduction and release of citrus whitefly natural enemies. [ABSTRACT FROM AUTHOR]

Simple Summary: Bemisia tabaci is a complex of whitefly species, of which MEAM1 and MED species are highly invasive crop pests worldwide. The ecology of B. tabaci is affected by infections of facultative endosymbiotic bacteria, which may result in fitness benefits to their hosts, thus facilitating their adaptation to new environments. In some insects, endosymbionts protect their hosts from attack by parasitoid wasps by supplementing the host's genetic defences. Parasitoids are effective biological control agents of B. tabaci. Understanding the variation in susceptibility to parasitization between whitefly strains harbouring different endosymbiotic bacteria is of practical importance. Here, we focused on MED species using two strains of the Q1 lineage, one infected with Hamiltonella and Cardinium (BtHC), and the other with Hamiltonella and Rickettsia (BtHR). We first saw no difference between BtHC and BtHR in parasitization by Eretmocerus mundus when reared on BtHC. On the other hand, BtHC nymphs were more resistant than BtHR after E. mundus were reared on BtHR for four generations. The same was observed after seven generations. Our findings showed that host strain is a factor affecting the ability of E. mundus to parasitize B. tabaci and support the hypothesis of Cardinium as a protective symbiont of the MED species. Moreover, our findings suggest that counteradaptations to B. tabaci defence mechanisms that maximize the parasitoid fitness may be rapidly selected in E. mundus. In this study, two strains of the mitochondrial lineage Q1 of Bemisia tabaci MED species, characterized by a different complement of facultative bacterial endosymbionts, were tested for their susceptibility to be attacked by the parasitoid wasp Eretmocerus mundus, a widespread natural enemy of B. tabaci. Notably, the BtHC strain infected with Hamiltonella and Cardinium was more resistant to parasitization than the BtHR strain infected with Hamiltonella and Rickettsia. The resistant phenotype consisted of fewer nymphs successfully parasitized (containing the parasitoid mature larva or pupa) and in a lower percentage of adult wasps emerging from parasitized nymphs. Interestingly, the resistance traits were not evident when E. mundus parasitism was compared between BtHC and BtHR using parasitoids originating from a colony maintained on BtHC. However, when we moved the parasitoid colony on BtHR and tested E. mundus after it was reared on BtHR for four and seven generations, we saw then that BtHC was less susceptible to parasitization than BtHR. On the other hand, we did not detect any difference in the parasitization of the BtHR strain between the three generations of E. mundus tested. Our findings showed that host strain is a factor affecting the ability of E. mundus to parasitize B. tabaci and lay the basis for further studies aimed at disentangling the role of the facultative endosymbiont Cardinium and of the genetic background in the resistance of B. tabaci MED to parasitoid attack. Furthermore, they highlight that counteradaptations to the variation of B. tabaci defence mechanisms may be rapidly selected in E. mundus to maximize the parasitoid fitness. [ABSTRACT FROM AUTHOR]

Simple Summary: The results from this study, conducted under farmer field conditions, show that application of the insecticide flupyradifurone through cassava cutting dips is effective at reducing whitefly numbers and cassava mosaic disease incidence and increasing cassava root yield. Insecticide application through cutting dips is geared as an integrated pest management strategy that could limit the trophic transfer of pesticides. We found that the rate of parasitism by individual parasitoid species was not significantly affected by the application of flupyradifurone. This strategy could be scaled further for the management of whiteflies in cassava, while at the same time minimizing the impact on non-target beneficial insects. The cassava whitefly Bemisia tabaci causes damage in cassava through the feeding and vectoring of plant viruses that cause cassava mosaic and cassava brown streak diseases. This study sought to explore the efficacy of cutting dipping in flupyradifurone for whitefly control and the impact of the mode of application on whitefly parasitism under farmer field conditions. The insecticide treatment significantly reduced adult whiteflies by 41%, nymphs by 64%, and cassava mosaic disease (CMD) incidence by 16% and increased root yield by 49%. The whitefly parasitism rate by Encarsia spp. parasitoids was 27.3 and 21.1%, while Eretmocerus spp. had 26.7 and 18.0% in control and flupyradifurone, respectively, and these differences were not significant. Electropenetrography recordings of whitefly feeding behaviour on flupyradifurone-treated plants showed significantly reduced probing activity and a delay in reaching the phloem as compared to the control. The findings from this study demonstrated that cassava cutting dipping in flupyradifurone significantly reduces whitefly numbers and cassava mosaic disease incidence, thus contributing to a significant root yield increase in cassava. Flupyradifurone applied through cutting dips does not significantly impact parasitism rates in cassava fields. Routine monitoring of parasitoids and predators in insecticide-treated versus control fields should be emphasized to determine the impact of pesticides on these beneficial non-target organisms. [ABSTRACT FROM AUTHOR]

Simple Summary: Cassava (Manihot esculenta Crantz; Euphorbiaceae) plants have a long lifecycle. They remain in the field for at least 10 months and are exposed to numerous pests. Seventeen groups of pests that affect this crop have been identified. These include 35 species found in the Americas, 11 in Africa, and 6 in Asia, totalling approximately 200 arthropod species that feed on cassava. Whiteflies are considered one of the main pests of cassava worldwide. In northeastern Brazil, the most common whitefly species causing severe damage to cassava is Aleurothrixus aepim (Goeldi, 1886) (Hemiptera: Aleyrodidae). Cassava plants emit volatile organic compounds and secrete extrafloral nectar; these substances may be essential for developing biological control strategies against pests. Herein, we describe variations in the blend constitution and individual concentrations of constitutive volatile organic compounds released by two cassava genotypes. Additionally, we highlight the activity of a monoterpene, considering that the resistant genotype emitted higher concentrations of this compound. Cassava is an essential tuber crop used to produce food, feed, and beverages. Whitefly pests, including Aleurothrixus aepim (Goeldi, 1886) (Hemiptera: Aleyrodidae), significantly affect cassava-based agroecosystems. Plant odours have been described as potential pest management tools, and the cassava clone M Ecuador 72 has been used by breeders as an essential source of resistance. In this study, we analysed and compared the volatile compounds released by this resistant clone and a susceptible genotype, BRS Jari. Constitutive odours were collected from young plants and analysed using gas chromatography–mass spectrometry combined with chemometric tools. The resistant genotype released numerous compounds with previously described biological activity and substantial amounts of the monoterpene (E)-β-ocimene. Whiteflies showed non-preferential behaviour when exposed to volatiles from the resistant genotype but not the susceptible genotype. Furthermore, pure ocimene caused non-preferential behaviour in whiteflies, indicating a role for this compound in repellence. This report provides an example of the intraspecific variation in odour emissions from cassava plants alongside information on odorants that repel whiteflies; these data can be used to devise whitefly management strategies. A better understanding of the genetic variability in cassava odour constituents and emissions under field conditions may accelerate the development of more resistant cassava varieties. [ABSTRACT FROM AUTHOR]

While so many insect species are under pressure from environmental effects, insect pests seem to increase their population sizes under CC. Climate change (CC) poses one of the foremost challenges for humanity in the 21st century. This study clearly underlines that CC impact studies have to include different future timespans to identify significant effects on insects' lifecycles in a changing environment, potentially leading to changes in their spatio-temporal dynamics. Insects are the focus of CC impact studies due to their role as important pests in agriculture and forestry [2,3] as well as their role in contributing to different ecosystem services [4]. [Extracted from the article]

Simple Summary: Encarsia (Family Aphelinidae) is a genus of minute parasitoid wasps that target a diversity of agricultural pest insects including whiteflies and armoured scale insects. Since the genus was described in 1878, 450+ species of Encarsia have been described. Historically, it has been difficult to provide a subgeneric classification for the species of Encarsia. As a result, researchers have divided the group into numerous informal species-groups. Our work uses an alignment of ribosomal DNA sequences (sequences that code for ribosomal RNA) to construct a phylogenetic tree that shows that species of the genus Dirphys are correctly placed within Encarsia. With these results, we establish the Encarsia mexicana species-group (for the six species previously placed in Dirphys) and describe 14 new species. We also briefly discuss morphological characters that may correspond to the relationships recovered in the molecular phylogeny. With this information, we can better understand the patterns of evolution which brought about the present diversity within Encarsia and provide a more accurate classification of the genus. The genus Dirphys Howard 1914 syn. n. is synonymized with Encarsia Förster, and treated as a species-group of Encarsia, referred to henceforth as the Encarsia mexicana species-group. The monophyly of Encarsia is discussed in relation to Dirphys. The new synonymy is based on phylogenetic analyses of the nuclear ribosomal 28S-D2 gene region (43 taxa, 510 bp). The Encarsia mexicana species-group is recovered as strongly monophyletic within Encarsia. All species of the Encarsia mexicana species-group are revised. The group includes six previously described species, and fourteen newly described species. All species are described (or redescribed) and illustrated. Detailed distributional data, and, where available, plant associate and host records are provided for all species. Encarsia myartsevae Kresslein and Polaszek nom. nov. is here proposed as a replacement name for Encarsia mexicana Myartseva, now preoccupied by Encarsia mexicana (Howard). A dichotomous identification key, supplemented by an online multiple-entry key, is provided for all species. [ABSTRACT FROM AUTHOR]

Simple Summary: The sweet potato whitefly is a major pest of crops worldwide, causing significant damage. To control this pest, farmers often use insecticides, but the effectiveness of these treatments can vary depending on resistant population dynamics. We investigated the efficacy of insecticides on adult whiteflies in the field and laboratory conditions using maximum labeled rate methods. Fast-acting insecticides were more effective in controlling whitefly adults, and bioassays could be an effective tool for determining efficacy prior to expensive field applications. These findings will be valuable to farmers and researchers seeking to optimize control strategies for whiteflies, helping to reduce crop damage and improve yields. We conducted a rapid bioassay method to assess insecticide efficacy for controlling adult sweetpotato whitefly Bemisia tabaci in squash and cucumber crops before insecticide applications. The study aimed to evaluate the accuracy of a 24-hour laboratory bioassay in determining maximum dose insecticide efficacy in the field. Ten insecticides were evaluated using leaf-dip bioassays, and their effectiveness was tested across eight cucurbit field experiments in Georgia, USA, during the 2021 and 2022 field seasons. The maximum dose, defined as the highest labeled rate of an insecticide diluted in the equivalent of 935 L ha−1 of water, was used for all bioassays. Adult survival observed in the bioassay was compared to adult field count-based survival 24 h after treatment. A low concentration (1/10 rate) was used for imidacloprid, flupyradifurone, pyriproxyfen, and cyantraniliprole to assess insecticide tolerance in the whitefly population. Overall, significant positive correlation between laboratory bioassay and field efficacy was reported, explaining 50–91% of the observed variation. The addition of the low dosage was helpful, indicating that no rate response was consistent with susceptibility to the tested insecticide, while a rate response was associated with a loss of susceptibility between 2021 and 2022. [ABSTRACT FROM AUTHOR]

Simple Summary: Ethyl formate (EF) can be a potential alternative to methyl bromide for the disinfestation of the greenhouse whitefly, a quarantine pest that affects the exportation of Oriental melon. The study found that 8 g/m3 EF for 2 h at 5 °C could be used as a new phytosanitary treatment for melons (C. melo) for export with modified atmosphere packaging (MAP) to disinfest the greenhouse whitefly. Trialeurodes vaporariorum (Hemiptera: Aleyrodidae), commonly known as greenhouse whitefly, is one of the main insect pests of Oriental melon (Cucumis melo var L.) in South Korea. T. vaporariorum is of concern as a quarantine pest for the exportation of C. melo in Southeast Asian countries. Due to future restrictions on the use of methyl bromide (MB) during quarantine, ethyl formate (EF) represents a potential alternative. In this study, we evaluated EF for its efficacy (probit-9 values) in enabling the export of Oriental melons. The probit-9 value of EF for controlling T. vaporariorum was 3.02 g·h/m3 after 2 h of fumigation. We also assessed the phytotoxicity of EF on melons when using modified atmosphere packaging (MAP) under low-temperature conditions, which is required for export and trade, to extend shelf-life. In scaled-up trials, we found 8 g/m3 EF for 2 h at 5 °C to be suitable as a new phytosanitary treatment against greenhouse whitefly for exported Oriental melons when using MAP. No phytotoxic damage was found 28 d after fumigation at 5 °C in terms of five quality parameters (firmness, sugar content, mass loss, color change, and external damage). [ABSTRACT FROM AUTHOR]

Simple Summary: A study was conducted to survey the populations of insect pests and beneficials on different cultivars of snap bean in Georgia, USA. It is important to conserve the beneficials and to understand both the abundance and diversity of beneficials and pests in crops. The population dynamics of insect pests, pollinators, and natural enemies were evaluated on 24 snap bean cultivars weekly for six weeks. The number of sweetpotato whitefly eggs was lowest on cultivar 'Jade', whereas cultivars 'Gold Mine', 'Golden Rod', 'Long Tendergreen', and 'Royal Burgundy' supported the fewest whitefly nymphs. Cultivars 'Greencrop' and 'PV-857′ harbored fewer adult potato leafhoppers and tarnished plant bugs. The population peaks of adults were observed in Week 1 (25 days after plants emerged) for whitefly and Mexican bean beetle; Week 3 for cucumber beetle, kudzu bug, and potato leafhopper; Weeks 3 and 4 for thrips; Week 4 for tarnished plant bugs; and Weeks 5 and 6 for bees. Temperature and relative humidity correlated with the populations of whitefly, Mexican bean beetle, bees, and predator ladybird beetle. These results contribute crucial information to the agricultural community for the management of insect pests on snap beans. Snap bean is an important crop in the United States. Insecticides are commonly used against pests on snap bean, but many pests have developed resistance to the insecticides and beneficials are threatened by the insecticides. Therefore, host plant resistance is a sustainable alternative. Population dynamics of insect pests and beneficials were assessed on 24 snap bean cultivars every week for six weeks. The lowest number of sweetpotato whitefly (Bemisia tabaci) eggs was observed on cultivar 'Jade', and the fewest nymphs were found on cultivars 'Gold Mine', 'Golden Rod', 'Long Tendergreen', and 'Royal Burgundy'. The numbers of potato leafhopper (Empoasca fabae) and tarnished plant bug (Lygus lineolaris) adults were the lowest on cultivars 'Greencrop' and 'PV-857′. The highest numbers of adults were found in Week 1 (25 days following plant emergence) for B. tabaci and Mexican bean beetle (Epilachna varivestis); Week 3 for cucumber beetle, kudzu bug (Megacopta cribraria), and E. fabae; Weeks 3 and 4 for thrips; Week 4 for L. lineolaris; and Weeks 5 and 6 for bees. Temperature and relative humidity correlated with B. tabaci, E. varivestis, bee, and predator ladybird beetle populations. These results provide valuable information on the integrated pest management of snap beans. [ABSTRACT FROM AUTHOR]

Simple Summary: The whitefly Bemisia tabaci is an invasive pest that causes extensive damage to many vegetable crops and ornamental plants. To control this pest, the release of natural enemies has become increasingly important as an ecologically safe and effective method of biological control. Some species in the family Miridae are effective at controlling whitefly populations, but because they feed on both insect prey and plant tissue, their overall effect on plant performance is not well understood. In this study, the impact of the mirid predator Macrolophus pygmaeus on the morphological and physiological traits of Solanum melongena in the presence of Bemisia tabaci was evaluated. Overall, the results show how the presence of this natural enemy mitigates the damage caused by whitefly infestations. They also help to clarify the multitrophic relationships between plant, pest, and natural enemy, enabling the prediction of plant development in the presence of both pest and predator. Nowadays, in protected vegetable crops, pest management based mainly on biological control represents the most sustainable alternative to pesticide use. The cotton whitefly, Bemisia tabaci, is one of the key pests that negatively impact the yield and quality of such crops in many agricultural systems. The predatory bug Macrolophus pygmaeus is one of the main natural enemies of the whitefly and is widely used for its control. However, the mirid can sometimes behave as a pest itself, causing damage to crops. In this study, we investigated the impact of M. pygmaeus as a plant feeder, by analyzing the combined impact of the whitefly pest and the predator bug on the morphology and physiology of potted eggplants under laboratory conditions. Our results showed no statistical differences between the heights of plants infested by the whitefly or by both insects compared with noninfested control plants. However, indirect chlorophyll content, photosynthetic performance, leaf area, and shoot dry weight were all greatly reduced in plants infested only by B. tabaci, compared with those infested by both pest and predator or with noninfested control plants. Contrarily, root area and dry weight values were more reduced in plants exposed to both of the insect species, compared with those infested only by the whitefly or compared with noninfested control plants, where the latter showed the highest values. These results show how the predator can significantly reduce the negative effects of B. tabaci infestation, limiting the damage it causes to host plants, though the effect of the mirid bug on the underground parts of the eggplant remains unclear. This information might be useful for a better understanding of the role that M. pygmaeus plays in plant growth, as well as for the development of management strategies to successfully control infestations by B. tabaci in cropping environments. [ABSTRACT FROM AUTHOR]

Simple Summary: The cassava is an important food crop in many regions of the world, mainly in the African continent and Brazilian regions. Pest occurrence has been the main limiting factor towards high productivity. The objective of this study was to identify the relationship between two whitefly species' occurrences and leaf characteristics in different cassava cultivars. Fewer whitefly nymphs were observed in cultivars with the lowest trichome density, highest light reflection and chroma in leaves. These cultivars could be recommended in areas where whiteflies have an infestation history. The morphological characteristics of cassava leaves such as trichome density, light reflection and chroma, should all be considered in future resistance breeding programs. The whitefly species Bemisia tuberculata and Aleurotrixus aepim (Hemiptera: Aleyrodidae) are considered important cassava (Manihot esculenta) pests. Leaf color and other morphological characteristics can influence the pest's interactions with the host plants. Thus, this study aimed to identify the relationship between whitefly occurrence and trichome density and leaf color in different cassava cultivars. The study was conducted in the field during the 2014/2015 and 2016/2017 crop seasons. The whitefly occurrence was surveyed in the cultivars, IAPAR 19, IPR Upira, IPR União, IAC 576-70, IAC 14, IAC 90, Catarina Branca, Santa Helena and Baianinha. The whitefly nymph quantification was correlated with non-glandular trichome density, luminosity (L*) and chroma (a* and b*) of the cassava leaves. IAPAR 19 and IAC 14 were less infested by whitefly nymphs when contrasted with IPR União, IPR Upira and Baianinha, which were the most infested. The lowest B. tuberculata infestations were correlated with lesser trichome density, highest light reflection and highest chroma in the sprout and the plant's superior third portion leaves. Low A. aepim infestation in both crop seasons made it impossible to verify its correlation with the studied cassava plant characteristics. The cultivars IAPAR 19 and IAC 14 could contribute towards B. tuberculata management in regions with a history of whitefly infestation. [ABSTRACT FROM AUTHOR]

Simple Summary: Rickettsia is a maternally transmitted endosymbiotic bacterium that infects most insect species. In the current study, we investigated the biological and physiological effects of Rickettsia infection on whitefly, Bemisia tabaci. Our results revealed that infection with Rickettsia increased the fertility, survivorship, and shortened the nymphal developmental duration of whitefly Bemisia tabaci. Rickettsia infected B. tabaci had significantly higher glycogen, soluble sugar and trehalose contents than those of Rickettsia negative B. tabaci individuals. When exposed to the entomopathogenic fungus Akanthomyces attenuatus and the insecticides imidacloprid and spirotetramat, Rickettsia infested B. tabaci had lower mortality rates and higher semi-lethal concentrations (LC50). The parasitism by Encarsia formosa was also reduced by Rickettsia infection. Endosymbionts play an essential role in the biology, physiology and immunity of insects. Many insects, including the whitefly Bemisia tabaci, are infected with the facultative endosymbiont Rickettsia. However, the mutualism between Rickettsia and its whitefly host remains unclear. This study investigated the biological and physiological benefits of Rickettsia infection to B. tabaci. Results revealed that infection of Rickettsia increased the fertility, the survival rate from nymph to adult and the number of female whiteflies. In addition, this facilitation caused a significant reduction in nymphal developmental duration but did not affect percentage rate of egg hatching. Rickettsia infected B. tabaci had significantly higher glycogen, soluble sugar and trehalose contents than Rickettsia negative B. tabaci individuals. Rickettsia also improved the immunity of its whitefly hosts. Rickettsia infested B. tabaci had lower mortality rates and higher semi-lethal concentrations (LC50) when exposed to the fungus Akanthomyces attenuatus and the insecticides imidacloprid and spirotetramat. The percentage of parasitism by Encarsia formosa was also reduced by Rickettsia infection. Overall, Rickettsia infection benefits B. tabaci by improving the nutritional composition of its host, and also protects B. tabaci by enhancing its resistance towards insecticides (imidacloprid and spirotetramat), entomopathogenic fungi (A. attenuatus) and its main parasitoid (E. formosa); all of which could significantly impact on current management strategies. [ABSTRACT FROM AUTHOR]

Simple Summary: Cassava-colonizing Bemisia tabaci whitefly negatively impact cassava production in sub-Saharan Africa through transmission of viruses that cause cassava mosaic disease (CMD) and cassava brown streak disease (CBSD). This study evaluated the efficacy of a novel insecticide flupyradifurone against this whitefly pest through standard spraying and cutting dip methods. The results from the laboratory, screenhouse and field experiments consistently showed flupyradifurone is effective at reducing whiteflies compared to control treatments. A single cutting dip using this insecticide was highly effective at reducing whiteflies under field conditions and, therefore, should be considered as an alternative to insecticide spraying in cassava systems. Additionally, whiteflies were least abundant during the long rainy season (Masika) and on cassava variety Mkuranga1. A novel butenolide insecticide—flupyradifurone (Sivanto SL 200)—was evaluated for efficacy against cassava-colonizing Bemisia tabaci whitefly under laboratory, screenhouse and field conditions. LC50 values from leaf disc spray assays were comparable for both flupyradifurone (12.7 g a.i/100 L) and imidacloprid (12.6 g a.i/100 L). Both insecticides caused high levels of adult whitefly mortality in leaf disc and leaf dip assays when compared to untreated controls. In screenhouse-based trials, longer soaking (60 min) with flupyradifurone or imidacloprid was more effective than shorter soaking durations (15 or 30 min). In field spraying experiments, flupyradifurone significantly reduced whiteflies, and both insecticides demonstrated powerful knockdown effects on whitefly adult abundances over a period up to 24 h. Single cutting dip application of flupyradifurone reduced whitefly adult abundance by 2 to 6 times, and nymphs by 2 to 13 times. Lower whitefly abundances resulting from insecticide application reduced the incidence of CMD or CBSD. In addition, in field experiments, whiteflies were fewer during the long rainy season (Masika) and on cassava variety Mkuranga1. The findings from this study demonstrate that cutting dips with flupyradifurone could be incorporated as a management tactic against cassava whiteflies. This would ideally be combined in an IPM strategy with other cassava virus and virus vector management tactics including host-plant resistance, phytosanitation and the use of clean seed. [ABSTRACT FROM AUTHOR]

Simple Summary: The whitefly species Bemisia tabaci is a known pest of cassava and a vector of cassava geminiviruses in Africa and India, but its role in the recent spread of Cassava Mosaic Disease (CMD) in Southeast Asia is not well known. This is in part due to a lack of data on the occurrence and distribution of B. tabaci in this region. We show here the first results of any country-wide survey and identification of B. tabaci colonizing cassava in Lao PDR. Cassava Mosaic Disease (CMD) caused by Sri Lankan cassava mosaic virus (SLCMV), has rapidly spread in Southeast Asia (SEA) since 2016. Recently it has been documented in Lao PDR. Previous reports have identified whitefly species of B. tabaci as potential vectors of CMD in SEA, but their occurrence and distribution in cassava fields is not well known. We conducted a countrywide survey in Lao PDR for adult whiteflies in cassava fields, and determined the abundance and genetic diversity of the B. tabaci species complex using mitochondrial cytochrome oxidase I (mtCOI) sequencing. In order to expedite the process, PCR amplifications were performed directly on whitefly adults without DNA extraction, and mtCOI sequences obtained using nanopore portable-sequencing technology. Low whitefly abundances and two cryptic species of the B. tabaci complex, Asia II 1 and Asia II 6, were identified. This is the first work on abundance and genetic identification of whiteflies associated with cassava in Lao PDR. This study indicates currently only a secondary role for Asia II in spreading CMD or as a pest. Routine monitoring and transmission studies on Asia II 6 should be carried out to establish its potential role as a vector of SLCMV in this region. [ABSTRACT FROM AUTHOR]

Whitefly Sampling Adults of cassava-colonizing whiteflies were collected from the shoot tips of 3-7-month-old cassava plants during surveys carried out in five provinces of DRC (Haut-Katanga, Ituri, Nord-Kivu, Sud-Kivu, and Tanganyika) from 2016 to 2018. Sequencing data from this study suggest that I B. afer i comprises approximately 45% of the whiteflies collected on cassava in eastern DRC and is predominant in the provinces of Tanganyika and Haut-Katanga compared to cassava I B. tabaci i . Cassava plants in Africa are colonized by several whitefly species, but the most predominant are I Bemisia tabaci i and I B. afer. i The greatest damage is caused by I B. tabaci i through the transmission of cassava mosaic begomoviruses (CMBs) [[9]] and cassava brown streak ipomoviruses (CBSIs) [[11]]. 29096025 26 Chen W., Wosula E.N., Hasegawa D.K., Casinga C., Shirima R.R., Fiaboe K.K.M., Hanna R., Fosto A., Goergen G., Tamò M. Genome of the African cassava whitefly Bemisia tabaci and distribution and genetic diversity of cassava-colonizing whiteflies in Africa. [Extracted from the article]

The current morphological characteristics, number of submarginal spines, number of marginal teeth, arrangement of submedian abdominal spines, and microscopic papillae failed to separate I Aleurocanthus i cf. I A. spiniferus i (F2X20) from I A. spiniferus i , which is genetically different from I A. spiniferus i and I A. camelliae i (Figure 2). The discovery of the novel cryptic species, I Aleurocanthus i cf. I A. spiniferus i , linked the history of adaptation among I A. spiniferus i and I A. camelliae i , suggesting that the most recent common ancestor of I A. camelliae i morphospecies is the I A. spiniferus i morphospecies that inhabits I Theaceae i sensu lato ( I Pentaphylacaceae i ). Whiteflies morphologically identical to I A. spiniferus i ( I Aleurocanthus i sp. in I E. japonica i and I A. spiniferus i in I Citrus i ) were grouped into uninfected populations, whereas I A. camelliae i B1 from I C. sinensis i was considered the I Wolbachia i -infected population. The I A. camelliae i cryptic species complex consists of at least three related species ( I Aleurocanthus woglumi i , I Aleurocanthus spiniferus i , and I A. camelliae i ) [[16]] and five associated haplotypes ( I A. camelliae i haplotypes B1-B3 and I A. spiniferus i haplogroup A1 and A2) [[19]]. [Extracted from the article]

Simple Summary: Bemisia tabaci Middle East–Asia Minor I (MEAM1) is a widely distributed invasive agricultural pest that causes extensive damage to agricultural, horticultural, and ornamental crops. Laccase2 (Lac2), a phenol oxidase, plays an important role in cuticle tanning of some insects. However, the function of Lac2 in whitefly remains unclear. In this study, we identified a BtLac2 gene in MEAM1 that is expressed in all developmental stages, and its expression in the cuticle is especially high. Knockdown of BtLac2 in nymphs produced thinner and fragile cuticles, which significantly increased the mortality rate and extended the development duration of nymphs, as well as further decreasing the emergence rate of adults. Overall, BtLac2 plays an important role in cuticle hardening of whitefly, suggesting a potential management strategy using RNAi to knock down BtLac2 expression. Cuticle sclerotization is critical for insect survival. Laccase2 (Lac2) is a phenol oxidase that plays a key role in cuticle formation and pigmentation in a variety of insects. However, the function of Lac2 in whitefly, Bemisia tabaci, remains unclear. In this study, we identified a BtLac2 gene in B. tabaci MEAM1 and found that BtLac2 was expressed in all stages. It was highly expressed in the egg stage, followed by nymph and adult. Moreover, the expression of BtLac2 was higher in the cuticle than in other tissues. Knockdown of BtLac2 in nymphs produced thinner and fragile cuticles, which significantly increased the mortality rate, extended the development duration of nymphs, and decreased the emergence rate of adults. This result demonstrates that BtLac2 plays an important role in the cuticle hardening of B. tabaci and suggests a potential management strategy using RNAi to knock down BtLac2 expression. [ABSTRACT FROM AUTHOR]

Simple Summary: Transposable elements (TEs) are mobile DNA sequences hosted in the genomes of various organisms. These elements have the ability to mediate regulatory changes, which can result in changes in gene expression. Bemisia tabaci is an important agricultural pest that has been linked to several cases of insecticide resistance. In this study, we conducted a genome-wide screening of TEs in the B. tabaci genome using bioinformatics tools. Results revealed a total of 1,292,393 TE copies clustered into 4872 lineages. The TE insertion site analysis revealed 94 insertions within or near defensome genes. Transposable elements (TEs) are genetically mobile units that move from one site to another within a genome. These units can mediate regulatory changes that can result in massive changes in genes expression. In fact, a precise identification of TEs can allow the detection of the mechanisms involving these elements in gene regulation and genome evolution. In the present study, a genome-wide analysis of the Hemipteran pest Bemisia tabaci was conducted using bioinformatics tools to identify, annotate and estimate the age of TEs, in addition to their insertion sites, within or near of the defensome genes involved in insecticide resistance. Overall, 1,292,393 TE copies were identified in the B. tabaci genome grouped into 4872 lineages. A total of 699 lineages were found to belong to Class I of TEs, 1348 belong to Class II, and 2825 were uncategorized and form the largest part of TEs (28.81%). The TE age estimation revealed that the oldest TEs invasion happened 14 million years ago (MYA) and the most recent occurred 0.2 MYA with the insertion of Class II TE elements. The analysis of TE insertion sites in defensome genes revealed 94 insertions. Six of these TE insertions were found within or near previously identified differentially expressed insecticide resistance genes. These insertions may have a potential role in the observed insecticide resistance in these pests. [ABSTRACT FROM AUTHOR]

Simple Summary: Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) has a cosmopolitan distribution, and it is a feared pest of many agricultural crops. It is a complex of numerous genetically differentiated species, most of which may rapidly acquire insecticide resistance, consequently making their control problematic. This study aims to improve knowledge on the direct damage of this pest, as well as its impact on the main traits of vegetable crops. Overall, the results confirm how different host plants display variable susceptibility to B. tabaci infestation and explain trophic links between plant and pest forecasting plant growth and development under B. tabaci presence. Although many crops have developed several adaptation mechanisms that allow them to defend against limiting factors, some biotic and abiotic stresses may cause reversible or irreversible changes in plants. Among the biotic stresses, the whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is probably one of the main important pests that negatively affect several vegetable crops that are grown in greenhouses. The present study evaluated its impact on the morphology and physiology of two solanaceous plants, i.e., tomato (Solanum lycopersicum L.) and eggplant (S. melongena L.), under laboratory conditions. The results showed that, for tomatoes, plant height, shoot dry weight, leaf area, and indirect chlorophyll content were strongly reduced in infested plants, compared to the uninfested control, by 39.36%, 32.37%, 61.01%, and 37.85%, respectively. The same has been shown for eggplant, although the reduction percentages of plant height, root dry weight, and indirect chlorophyll content were less marked (i.e., 16.15%, 31.65%, and 11.39%, respectively). These results could represent interesting information for a better understanding of the B. tabaci influence on plant growth, as well as for the development of management strategies to successfully control its infestations in a cropping system. [ABSTRACT FROM AUTHOR]

Bemisia tabaci (Gennadius), Trialeurodes vaporariorum (Westwood), and Siphoninus phillyreae (Haliday) are whitefly species that harm agricultural crops in many regions of the world. These insects live in close association with bacterial symbionts that affect host fitness and adaptation to the environment. In the current study, we surveyed the infection of whitefly populations in Southeast Europe by various bacterial symbionts and performed phylogenetic analyses on the different symbionts detected. Arsenophonus and Hamiltonella were the most prevalent symbionts in all three whitefly species. Rickettsia was found to infect mainly B. tabaci, while Wolbachia mainly infected both B. tabaci and S. phillyreae. Furthermore, Cardinium was rarely found in the investigated whitefly populations, while Fritschea was never found in any of the whitefly species tested. Phylogenetic analyses revealed a diversity of several symbionts (e.g., Hamiltonella, Arsenophonus, Rickettsia), which appeared in several clades. Reproductively isolated B. tabaci and T. vaporariorum shared the same (or highly similar) Hamiltonella and Arsenophonus, while these symbionts were distinctive in S. phillyreae. Interestingly, Arsenophonus from S. phillyreae did not cluster with any of the reported sequences, which could indicate the presence of Arsenophonus, not previously associated with whiteflies. In this study, symbionts (Wolbachia, Rickettsia, and Cardinium) known to infect a wide range of insects each clustered in the same clades independently of the whitefly species. These results indicate horizontal transmission of bacterial symbionts between reproductively isolated whitefly species, a mechanism that can establish new infections that did not previously exist in whiteflies. [ABSTRACT FROM AUTHOR]

Whiteflies, Bemisia tabaci (Gennadius) are major insect pests that affect many crops such as cassava, tomato, beans, cotton, cucurbits, potato, sweet potato, and ornamental crops. Bemisia tabaci transmits viral diseases, namely cassava mosaic and cassava brown streak diseases, which are the main constraints to cassava production, causing huge losses to many small-scale farmers. The aim of this work was to determine the phylogenetic relationships among Bemisia tabaci species in major cassava growing areas of Kenya. Surveys were carried out between 2013 and 2015 in major cassava growing areas (Western, Nyanza, Eastern, and Coast regions), for cassava mosaic disease (CMD) and cassava brown streak disease (CBSD). Mitochondrial cytochrome oxidase I (mtCOI-DNA) was used to determine the genetic diversity of B. tabaci. Phylogenetic trees were constructed using Bayesian methods to understand the genetic diversity across the study regions. Phylogenetic analysis revealed two B. tabaci species present in Kenya, sub-Saharan Africa 1 and 2 comprising five distinct clades (A-E) with percent sequence similarity ranging from 97.7 % to 99.5%. Clades B, C, D, and E are predominantly distributed in the Western and Nyanza regions of Kenya whereas clade B is dominantly found along the coast, the eastern region, and parts of Nyanza. Our B. tabaci clade A groups with sub-Saharan Africa 2-(SSA2) recorded a percent sequence similarity of 99.5%. In this study, we also report the identification of SSA2 after a 15 year absence in Kenya. The SSA2 species associated with CMD has been found in the Western region of Kenya bordering Uganda. More information is needed to determine if these species are differentially involved in the epidemiology of the cassava viruses. [ABSTRACT FROM AUTHOR]

Our greenhouse tomatoes have suffered from attacks by viruliferous whiteflies Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) over the last 10 years. The fundamental countermeasure was the application of an electric field screen to the greenhouse windows to prevent their entry. However, while the protection was effective, it was incomplete, because of the lack of a guard at the greenhouse entrance area; in fact, the pests entered from the entrance door when workers entered and exited. To address this, we developed a portable electrostatic insect sweeper as a supplementary technique to the screen. In this sweeper, eight insulated conductor wires (ICWs) were arranged at constant intervals along a polyvinylchloride (PVC) pipe and covered with a cylindrical stainless net. The ICWs and metal net were linked to a DC voltage generator (operated by 3-V alkaline batteries) inside the grip and oppositely electrified to generate an electric field between them. Whiteflies on the plants were attracted to the sweeper that was gently slid along the leaves. This apparatus was easy to operate on-site in a greenhouse and enabled capture of the whiteflies detected during the routine care of the tomato plants. Using this apparatus, we caught all whiteflies that invaded the non-guarded entrance door and minimized the appearance and spread of the viral disease in tomato plants in the greenhouse. [ABSTRACT FROM AUTHOR]

The sweetpotato whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a pest of global importance on both outdoor and glasshouse crops. To date, B. tabaci has not become established in the UK. The UK holds Protected Zone status against this pest and, as a result, B. tabaci entering on plant material is subjected to a policy of eradication. Mediterranean species is now the most prevalent Bemisia species entering the UK. Increasing neonicotinoid resistance is becoming increasingly widespread and problematic with this species. As a result, this continues to pose problems for eradication strategies. The current study investigates the efficacy of Tri-Tek (a petroleum horticultural oil awaiting UK registration) and the fungus Beauveria bassiana to act as control agents against Mediterranean species in UK glasshouses. Tri-Tek provided 100% egg mortality compared to 74% for B. bassiana. When tested against second instar larvae, mortalities of 69% and 65% respectively were achieved. Both products can be successfully "tank-mixed". A tank-mix application provided 95.5% mortality of second instar larvae under glasshouse conditions. The potential integration of both products into current Bemisia eradication strategies in UK glasshouses is discussed. [ABSTRACT FROM AUTHOR]

Simple Summary: Temperature is an important factor affecting all physiological activities of ectotherms. Invasive whiteflies can quickly adapt to new environments probably regulated by epigenetics. The results of a chromatin openness test also showed that the position of the chromatin opening of Bemisia tabaci undergoes significant change under different temperature stresses. However, the specific regulatory factors in this process have not yet been verified. In this study, we verified two key factors, cytochrome P450 4C1 and carbonic anhydrase 3, regulated by chromatin accessibility. Our findings can provide a potential mechanism for responses to temperature stress and a direction for other behavioral activities of insects, as well as in proposing strategies for controlling invasive populations of whitefly. The position of the chromatin opening of Bemisia tabaci undergoes significant changes under different temperature stresses, and numerous regulatory factors have been found. In this study, we verified two key factors, cytochrome P450 4C1 and carbonic anhydrase 3. The results showed that invasive whiteflies had a significantly lower heat resistance after silencing BtCYP 4C1 and BtCar3. In addition, whiteflies had a higher cold tolerance after silencing BtCYP 4C1. These results indicate that BtCYP 4C1 and BtCar3 are key regulators in the temperature adaptation of B. tabaci. Moreover, they may be key factors in influencing the geographical distribution and dispersal of B. tabaci as an invasive species in China. [ABSTRACT FROM AUTHOR]

Simple Summary: In the tropical and sub-tropical regions of Asia, Africa, and America, the Bemisia tabaci (cotton whitefly) has attained a major pest status of cotton. It produces injury to the plant by feeding, excreting honeydews, and by transmitting viruses on many crops. The heavy application of insecticides for controlling the insect pest is one of the main reasons for the outbreaks of whitefly. Due to several reports of control failure of the whitefly, the present study was conducted to evaluate the resistance development in B. tabaci. Therefore, the field population of B. tabaci was collected, and the resistance development was evaluated against the commonly used insecticides. For evaluating the development of resistance, the B. tabaci was selected with the insecticides under the controlled laboratory conditions. The data of mortality was calculated at each generation, and the overall development of resistance up to five generations was evaluated. Results showed that the field collected population was susceptible to the selected insecticides at G1, indicating their effectiveness. However, a continuous selection for only five generations resulted in a significant increase in the resistance development. The present study provided very valuable information on the resistance development in B. tabaci. Cotton is a major crop of Pakistan, and Bemisia tabaci (Homoptera: Aleyrodidae) is a major pest of cotton. Due to the unwise and indiscriminate use of insecticides, resistance develops more readily in the whitefly. The present study was conducted to evaluate the resistance development in the whitefly against the different insecticides that are still in use. For this purpose, the whitefly population was selected with five concentrations of each insecticide, for five generations. At G1, compared with the laboratory susceptible population, a very low level of resistance was observed against bifenthrin, cypermethrin, acetamiprid, imidacloprid, thiamethoxam, nitenpyram, chlorfenapyr, and buprofezin with a resistance ratio of 3-fold, 2-fold, 1-fold, 4-fold, 3-fold, 3-fold, 3-fold, and 3-fold, respectively. However, the selection for five generations increased the resistance to a very high level against buprofezin (127-fold), and to a high level against imidacloprid (86-fold) compared with the laboratory susceptible population. While, a moderate level of resistance was observed against cypermethrin (34-fold), thiamethoxam (34-fold), nitenpyram (30-fold), chlorfenapyr (29-fold), and acetamiprid (21-fold). On the other hand, the resistance was low against bifenthrin (18-fold) after selection for five generations. A very low level of resistance against the field population of B. tabaci, at G1, showed that these insecticides are still effective, and thus can be used under the field conditions for the management of B. tabaci. However, the proper rotation of insecticides among different groups can help to reduce the development of resistance against insecticides. [ABSTRACT FROM AUTHOR]

Simple Summary: Silverleaf whiteflies (Bemisia tabaci), vegetable leafminers (Liriomyza sativae), and western flower thrips (Frankliniella occidentalis) are very serious pests of greenhouse tomatoes. In Japan, growers of organic tomatoes currently use large numbers of yellow sticky traps to control insects, but these traps need replacing very regularly, as the sticky surface becomes clogged with insects. An electric field-generating apparatus, described herein, is a potential physical tool to control these pests that have entered greenhouses. The electric field was formed in the space between oppositely electrified insulated conductors arrayed in parallel with fixed separation. Although these conductors created a sufficiently strong force to capture insects entering the field, the force was insufficient to capture insects outside the field. The positive phototaxis of these insects was an inspiration to develop an improved electrostatic insect trap, which was constructed by introducing oppositely charged yellow-colored water into paired transparent insulator tubes to produce opposite poles. The finished apparatus exhibited coloration and insect attraction characteristics similar to commercial yellow sticky traps, but had the advantage that they could be cleaned easily and remain effective for long periods. The surfaces of the insulator tubes containing the charged yellow water were electrostatically active, but not excessively sticky, thus, the apparatus could be placed close to the plants. The close location of the devices enabled preferential attraction of flying or plant-settling insects to the trap. The present study provided an experimental basis for developing an electrostatic device to attract and capture insects that enter greenhouses. Our aim was to develop an electrostatic apparatus to lure and capture silverleaf whiteflies (Bemisia tabaci), vegetable leafminers (Liriomyza sativae), and western flower thrips (Frankliniella occidentalis) that invade tomato greenhouses. A double-charged dipolar electric field producer (DD-EFP) was constructed by filling water in two identical transparent soft polyvinyl chloride tubes arrayed in parallel with fixed separation, and then, inserting the probes of grounded negative and positive voltage generators into the water of the two tubes to generate negatively and positively charged waters, respectively. These charged waters electrified the outer surfaces of the opposite tubes via dielectric polarization. An electric field formed between the oppositely charged tubes. To lure these phototactic insects, the water was colored yellow using watercolor paste, then introduced into the transparent insulator tubes to construct the yellow-colored DD-EFP. This apparatus lured insects in a manner similar to commercially available yellow sticky traps. The yellow-colored DD-EFP was easily placed as a movable upright screen along the plants, such that invading pests were preferentially attracted to the trap before reaching the plants. Furthermore, pests settling on the plants were attracted to the apparatus, which used a plant-tapping method to drive them off the plants. Our study provided an experimental basis for developing an electrostatic device to attract and capture insects that enter greenhouses. [ABSTRACT FROM AUTHOR]

Simple Summary: The cabbage whitefly Aleyrodes proletella is a major insect pest of many cabbage crops. Natural enemies, in particular Encarsia tricolor as well as different hoverfly larvae and spiders, do not decrease pest populations sufficiently. The objective of this study is to promote local natural enemy populations by permanently establishing a non-pest whitefly species, which is an alternative host and additional food source when A. proletella is scarce or even absent. Therefore, the perennial abundance of the non-pest honeysuckle whitefly Aleyrodes lonicerae and natural enemies on different plants were evaluated in the open field. Wood avens Geum urbanum was the best host plant for A. lonicerae in terms of reproduction and overwintering. Most E. tricolor and spiders were also found on this plant species. In the future, G. urbanum might be used in non-crop habitats to increase natural enemy abundances in the agricultural landscape and decrease damage caused by A. proletella on adjacent cabbage plants. Aleyrodes proletella causes severe economic damage to several Brassica crops. Its naturally occurring enemies often immigrate late in the season or appear in low numbers on cabbage. This field study aims to permanently increase the local abundance of A. proletella's natural enemies by providing the non-pest whitefly Aleyrodes lonicerae as an alternative and overwintering host/prey. Therefore, the population dynamics of natural enemies on different perennial herbaceous plants pre-infested with A. lonicerae were determined at two field locations over two winter periods. Most A. lonicerae colonized (on average 166.22 puparia per m²) and overwintered (342.19 adults per m²) on wood avens Geum urbanum. Furthermore, the abundance of A. proletella main parasitoid Encarsia tricolor (28.50 parasitized puparia per m²) and spiders (12.13 per m²) was 3–74 times and 3–14 times higher, respectively, on G. urbanum compared to the other experimental plants. Conclusively, G. urbanum pre-infested with A. lonicerae permanently promoted natural enemies of A. proletella by serving as shelter, reproduction, and overwintering habitat. A potential implementation of G. urbanum in conservation biological control strategies (e.g., tailored flower strips, hedgerows) against A. proletella are discussed and suggestions for future research are given. [ABSTRACT FROM AUTHOR]

Simple Summary: The silverleaf whitefly (B. tabaci) is an important agricultural pest damaging several agricultural and horticultural crops worldwide. Keeping in mind the status of insecticide overuse, the current experiment was designed to evaluate the sensitivity of B. tabaci towards imidacloprid and thiamethoxam (two popularly used neonicotinoids in India). The lab population of B. tabaci was found to be more susceptible to thiamethoxam compared to imidacloprid. qPCR studies revealed a higher expression of insecticide-resistant genes, CYP6CM1 and CYP6CX1, after imidacloprid treatment that might be responsible for increased resistance to insecticides. Our results also put forward the different interactions between symbionts and insecticide resistance. qPCR studies revealed thiamethoxam-treated B. tabaci populations harbored a higher amount of primary endosymbiont Portiera and a lower amount of secondary symbiont Rickettsia. The silverleaf whitefly, Bemisia tabaci (Gennadius, Hemiptera: Aleyrodidae), is a major threat to field and horticultural crops worldwide. Persistent use of insecticides for the management of this pest is a lingering problem. In the present study, the status of sensitivity of B. tabaci to two neonicotinoids, imidacloprid and thiamethoxam, was evaluated. The expression pattern of two cytochrome P450 (cyp) genes and changes in the relative amount of symbionts in insecticide-treated B. tabaci were also assessed. Quantitative PCR (qPCR) studies indicate that the CYP6CM1 and CYP6CX1 genes were always expressed higher in imidacloprid-treated whitefly, suggesting a correlation between gene expression and the insect's ability to detoxify toxic compounds such as insecticides. In addition, the thiamethoxam-treated population harbored higher Portiera and lower Rickettsia titers, whereas the imidacloprid-treated population harbored more Rickettsia at different time intervals. Interestingly, we also examined that an increase in exposure to both the insecticides resulted in a reduction in the mutualistic partners from their insect host. These differential responses of endosymbionts to insecticide exposure imply the complex interactions among the symbionts inside the host insect. The results also provide a deeper understanding of the molecular mechanism of resistance development that might be useful for formulating effective management strategies to control B. tabaci by manipulating symbionts and detoxifying genes. [ABSTRACT FROM AUTHOR]

Simple Summary: Despite being a pest of global importance, effective management of whiteflies by the implication of environmentally friendly approaches is still a far-reaching task. In this review, we have tried to bring the readers' attention to next-generation control strategies such as RNA interference and genetic modifications of plants for the expression of anti-whitefly proteins. These strategies offer huge promise to provide an effective and sustainable solution to the problem of whiteflies, either in isolation or in combination with other widely used practices under the regimes of integrated pest management. Focus has also been given to advanced technologies such as nanotechnology and genome editing, with promising prospects for field applications. The importance, applicability, and demand of these technologies for the control of whiteflies have been highlighted. We have also attempted to present the holistic picture of challenges in the path of commercial application of these promising technologies. To underline the pest status of whiteflies concisely, we have enlisted all economically important species of the pest along with their host plants/crops across the world. A comprehensive list of various insecticides of chemical, microbial, and botanical origin, applied in the field for the control of sweetpotato whitefly along with their resistance status, ecotoxicities, and effects on biological control agents, has been provided for readers. Whiteflies are a group of universally occurring insects that are considered to be a serious pest in their own way for causing both direct and indirect damages to crops. A few of them serve as vectors of plant viruses that are detrimental to the crop in question and cause an actual loss in productivity. A lot of attention is focused on pest control measures under the umbrella of IPM. In this review, we attempt to summarize the existing literature on how and why whiteflies are a serious concern for agriculture and society. We reviewed why there could be a need for fresh insight into the ways and means with which the pest can be combated. Here, we have emphasized next-generation strategies based on macromolecules, i.e., RNA interference and genetic engineering (for the expression of anti-whitefly proteins), as these strategies possess the greatest scope for research and improvement in the future. Recent scientific efforts based on nanotechnology and genome editing, which seem to offer great potential for whitefly/crop pest control, have been discussed. Comprehensive apprehensions related to obstacles in the path of taking lab-ready technologies into the farmers' field have also been highlighted. Although the use of RNAi, GM crops, nanotechnologies, for the control of whiteflies needs to be evaluated in the field, there is an emerging range of possible applications with promising prospects for the control of these tiny flies that are mighty pests. [ABSTRACT FROM AUTHOR]

Simple Summary: Biological control (BC) is an effective way to regulate pest populations in horticultural crops, allowing the decrease of pesticide usage. On tomato, predatory insects like plant bugs or mirids provide BC services against several insect pests. Native predators are adapted to local conditions of climate and ecology and therefore may be well suited to provide BC services. Dicyphus cerastii is a predatory mirid that is present in the Mediterranean region and occurs in tomato greenhouses in Portugal. However, little is known about its contribution to BC in this crop. In this study, we evaluated how prey consumption is affected by increasing prey abundance on four different prey, in laboratory conditions. We found that the predator can increase its predation rate until a maximum is reached and that prey characteristics like size and mobility can affect predation. Dicyphus cerastii showed high predation rates for all prey species tested, allowing us to conclude that this species is an interesting predator for BC in tomato crops. Dicyphine mirids are important biological control agents (BCAs) in horticultural crops. Dicyphus cerastii Wagner can be found in protected tomato crops in Portugal, and has been observed feeding on several tomato pests. However, the predation capacity of this species is poorly studied. In order to investigate the predation capacity of D. cerastii, and how it is affected by prey size and mobility, we evaluated the functional response (FR) and predation rate of female predators on different densities of four prey species: Myzus persicae 1st instar nymphs (large mobile prey), Bemisia tabaci 4th instar nymphs, Ephestia kuehniella eggs (large immobile prey) and Tuta absoluta eggs (small immobile prey). Experiments were performed on tomato leaflets in Petri dish arenas for 24 h. Dicyphus cerastii exhibited type II FR for all prey tested. The predator effectively preyed upon all prey, consuming an average of 88.8 B. tabaci nymphs, 134.4 E. kuehniella eggs, 37.3 M. persicae nymphs and 172.3 T. absoluta eggs. Differences in the FR parameters, attack rate and handling time, suggested that prey size and mobility affected predation capacity. Considering the very high predation rates found for all prey species, D. cerastii proved to be an interesting candidate BCA for tomato crops. [ABSTRACT FROM AUTHOR]

Simple Summary: Bemisia tabaci is a key pest of horticultural, fibre and ornamental crops, primarily as a vector of plant viruses. This whitefly is considered as a complex of morphologically indistinguishable species that differ in several biological traits. In Italy, the Mediterranean (MED) and Middle East–Asia Minor 1 (MEAM1) species are known to be present in southern regions as well as in Sicily and Sardinia, where they have been responsible for economically important yield losses to horticultural crops since the 1990s. Recent reports of infestations in some areas of central Italy prompted a reassessment of the species distribution in the country, and several sites have been inspected at different central and southern regions and in the main islands. The survey confirmed that B. tabaci is nowadays established in central Italy even at more northern latitudes than those noticed before, with MED that is clearly prevailing on MEAM1 species throughout the country. The extensive presence of B. tabaci in Italy causes new concerns for the growing number of horticultural and ornamental productive sites that are potentially endangered by whitefly-transmitted viruses. The prevalence of the MED species is even more worrying for its ability to rapidly develop insecticide resistances. Bemisia tabaci is a key pest of horticultural, fibre and ornamental crops worldwide, primarily as a vector of plant viruses. In Italy, B. tabaci has established since the 1980s–1990s in southern regions as well as in Sicily and Sardinia. Recent reports of infestations in some areas of central Italy prompted a new survey to assess the whitefly distribution in the country as well as to update the species and haplotype composition of the populations present in southern Italy and in the main islands. The survey confirmed that B. tabaci is nowadays established in central Italy even at more northern latitudes than those noticed before. Most of the specimens collected throughout the country belonged to the Mediterranean (MED) species. The MEDQ1 and Q2 haplogroups were prevailing in open-field and greenhouse cultivations, respectively, except in Sardinia where only Q1 specimens were found on a wide range of crops and weeds. Population genetics analyses showed that several MEDQ1 haplotypes currently occur in Italy and their distribution is unrelated to evident temporal and geographic trends, except for a new genetic variant which seems to have originated in Sardinia. The MED species is known to better adapt to insecticide treatments and high temperatures, and its northward spread in Italy may have been favoured by the intensive agricultural practices and steady increase in both winter and summer temperatures occurring in the last few decades. The extensive presence of B. tabaci in Italy proves that a strict surveillance for possible new outbreaks of whitefly-transmitted viruses should be addressed to a range of sites that are expanding northwards. [ABSTRACT FROM AUTHOR]

Whitefly-transmitted viruses often cause much greater harm to the crop than the whitefly itself. Integration of host plant resistance and other control tactics may ultimately provide the best solution for both whitefly and whitefly-transmitted virus management [[7]]. Host plant resistance against whitefly-transmitted viruses [[6]] has been one of the more challenging and effective tactics for mitigating this complicating virus-effect on whitefly management. Whiteflies (Hemiptera: Aleyrodidae), especially the sweetpotato or cotton whitefly, I Bemisia tabaci i (Gennadius), are among the most destructive and difficult to manage polyphagous insect pests around the globe. [Extracted from the article]

Simple Summary: Whiteflies are pests and vectors of plant viruses which cause devastating yield losses globally to numerous food, cash and ornamental crops. The main whitefly (Bemisia tabaci) populations that infest cassava, a food security crop for sub-Saharan Africa (SSA), can reach highly abundant populations and are SSA1 and SSA2. SSA1 has been divided into separate species/subgroups (SG1/SG2 and SG3) and these can differ in their abundance and prevalence in the field in east Africa. In this study, biological traits of 12 whitefly populations collected from Uganda and Tanzania were investigated to determine whether their genotypes alone are significant drivers of the observed field abundance. Development of B. tabaci populations (SSA1 subgroups SG1/SG2 and SSA2) under insectary conditions were similar, hence not supporting previous suggestions of SSA1-SG1 being predominant in eastern Africa, due to distinct biological traits. SSA1-SG3 development time was the shortest, whereas SSA1-SG2 generated the greatest number of emerged adults. These results assist understanding of factors contributing to the outbreaking phenomenon of whitefly populations that drive cassava-virus pandemics in eastern Africa. In East Africa, the prevalent Bemisia tabaci whiteflies on the food security crop cassava are classified as sub-Saharan Africa (SSA) species. Economically damaging cassava whitefly populations were associated with the SSA2 species in the 1990s, but more recently, it has been to SSA1 species. To investigate whether biological traits (number of first instar nymphs, emerged adults, proportion of females in progeny and development time) of the cassava whitefly species are significant drivers of the observed field abundance, our study determined the development of SSA1 sub-group (SG) 1 (5 populations), SG2 (5 populations), SG3 (1 population) and SSA2 (1 population) on cassava and eggplant under laboratory conditions. SSA1-(SG1-SG2) and SSA2 populations' development traits were similar. Regardless of the host plant, SSA1-SG2 populations had the highest number of first instar nymphs (60.6 ± 3.4) and emerged adults (50.9 ± 3.6), followed by SSA1-SG1 (55.5 ± 3.2 and 44.6 ± 3.3), SSA2 (45.8 ± 5.7 and 32.6 ± 5.1) and the lowest were SSA1-SG3 (34.2 ± 6.1 and 32.0 ± 7.1) populations. SSA1-SG3 population had the shortest egg–adult emergence development time (26.7 days), followed by SSA1-SG1 (29.1 days), SSA1-SG2 (29.6 days) and SSA2 (32.2 days). Regardless of the whitefly population, development time was significantly shorter on eggplant (25.1 ± 0.9 days) than cassava (34.6 ± 1.0 days). These results support that SSA1-(SG1-SG2) and SSA2 B. tabaci can become highly abundant on cassava, with their species classification alone not correlating with observed abundance and prevalence. [ABSTRACT FROM AUTHOR]

Simple Summary: For the sake of growth and development, old exuviums of Bemisia tabaci nymphs should be periodically substituted by new ones until a final emergence turns them into adults. During ecdysis, chitinases are of great importance in chitin degradation and turnover of cuticles, which provides us potential targets for RNA interference-based B. tabaci management. Therefore, we annotated 14 chitinase and chitinase-like genes in B. tabaci based on data of genome and transcriptomes. With the help of a nanomaterial-promoted RNAi method, we found that silencing of BtCht10, BtCht5, and BtCht7 resulted in significant increase of death rate on B. tabaci nymphs and the developmental duration was noticeably postponed for BtCht2-silenced nymphs. Chitinases are of great importance in chitin degradation and remodeling in insects. However, the genome-wide distribution of chitinase-like gene family in Bemsia tabaci, a destructive pest worldwide, is still elusive. With the help of bioinformatics, we annotated 14 genes that encode putative chitinase-like proteins, including ten chitinases (Cht), three imaginal disk growth factors (IDGF), and one endo-β-N-acetylglucosaminidase (ENGase) in the genome of the whitefly, B. tabaci. These genes were phylogenetically grouped into eight clades, among which 13 genes were classified in the glycoside hydrolase family 18 groups and one in the ENGase group. Afterwards, developmental expression analysis suggested that BtCht10, BtCht5, and BtCht7 were highly expressed in nymphal stages and exhibit similar expression patterns, implying their underlying role in nymph ecdysis. Notably, nymphs exhibited a lower rate of survival when challenged by dsRNA targeting these three genes via a nanomaterial-promoted RNAi method. In addition, silencing of BtCht10 significantly resulted in a longer duration of development compared to control nymphs. These results indicate a key role of BtCht10, BtCht5, and BtCht7 in B. tabaci nymph molting. Our research depicts the differences of chitinase-like family genes in structure and function and identified potential targets for RNAi-based whitefly management. [ABSTRACT FROM AUTHOR]

Simple Summary: Tomato yellow leaf curl viruses cause disease epidemics in tomato crops in tropical and subtropical areas worldwide. The sweet potato whitefly, Bemisia tabaci, is a vector of this group of viruses. This research studied the transmission biology of tomato yellow leaf curl Thailand virus (TYLCTHV) by B. tabaci, including virus-infected tissues, virus translocation, virus replication, and transovarial transmission (i.e., transmission from mother to progeny via ovaries). We discovered that the virus first infects the alimentary gut, then the hemolymph, and finally the salivary glands of the whitefly. The virus did not replicate in the whitefly during infection. In addition, TYLCTHV was detected in only 10% of infected females' first-generation progeny, but the progeny was unable to cause viral infection of tomato plants; therefore, there was no evidence of transovarial transmission. When combined with the current literature, our results suggest that B. tabaci transmits TYLCTHV in a persistent-circulative mode. Viruses that cause tomato yellow leaf curl disease are part of a group of viruses of the genus Begomovirus, family Geminiviridae. Tomato-infecting begomoviruses cause epidemics in tomato crops in tropical, subtropical, and Mediterranean climates, and they are exclusively transmitted by Bemisia tabaci in the field. The objective of the present study was to examine the transmission biology of the tomato yellow leaf curl Thailand virus (TYLCTHV) by B. tabaci, including virus-infected tissues, virus translocation, virus replication, and transovarial transmission. The results demonstrated that the virus translocates from the alimentary gut to the salivary glands via the hemolymph, without apparent replication when acquired by B. tabaci. Furthermore, the virus was detected in 10% of the first-generation progeny of viruliferous females, but the progeny was unable to cause the viral infection of host plants. There was no evidence of transovarial transmission of TYLCTHV in B. tabaci. When combined with the current literature, our results suggest that B. tabaci transmits TYLCTHV in a persistent-circulative mode. The present study enhances our understanding of virus–vector interaction and the transmission biology of TYLCTHV in B. tabaci. [ABSTRACT FROM AUTHOR]

Simple Summary: The whitefly Bemisia tabaci has become a primary pest in soybean fields in Brazil over the last decades, causing losses in the yield. Its reduced size and fast population growth make monitoring a challenge for growers. The use of hyperspectral proximal sensing (PS) is a tool that allows the identification of arthropod infested areas without contact with the plants. This optimizes the time spent on crop monitoring, which is important for large cultivation areas, such as soybean fields in Brazilian Cerrado. In this study, we investigated differences in the responses obtained from leaves of soybean plants, non-infested and infested with Bemisia tabaci in different levels, with the aim of its differentiation by using hyperspectral PS, which is based on the information from many contiguous wavelengths. Leaves were collected from soybean plants to obtain hyperspectral signatures in the laboratory. Hyperspectral curves of infested and non-infested leaves were differentiated with good accuracy by the responses of the bands related to photosynthesis and water content. These results can be helpful in improving the monitoring of Bemisia tabaci in the field, which is important in the decision-making of integrated pest management programs for this key pest. Although monitoring insect pest populations in the fields is essential in crop management, it is still a laborious and sometimes ineffective process. Imprecise decision-making in an integrated pest management program may lead to ineffective control in infested areas or the excessive use of insecticides. In addition, high infestation levels may diminish the photosynthetic activity of soybean, reducing their development and yield. Therefore, we proposed that levels of infested soybean areas could be identified and classified in a field using hyperspectral proximal sensing. Thus, the goals of this study were to investigate and discriminate the reflectance characteristics of soybean non-infested and infested with Bemisia tabaci using hyperspectral sensing data. Therefore, cages were placed over soybean plants in a commercial field and artificial whitefly infestations were created. Later, samples of infested and non-infested soybean leaves were collected and transported to the laboratory to obtain the hyperspectral curves. The results allowed us to discriminate the different levels of infestation and to separate healthy from whitefly infested soybean leaves based on their reflectance. In conclusion, these results show that hyperspectral sensing can potentially be used to monitor whitefly populations in soybean fields. [ABSTRACT FROM AUTHOR]

Simple Summary: Whiteflies are one of the most important and widespread pests in the world. In South America, the currently most important species occurring are Bemisia afer,Trialeurodes vaporariorum, and the cryptic species Middle East-Asia Minor 1, Mediterranean, and New World, from Bemisia tabaci complex. The present review compiles information from several studies conducted in South America regarding these insects, providing data related to the dynamics and distribution of whiteflies, the associated viruses, and the management strategies to keep whiteflies under the economic damage threshold. By having an extensive territory and suitable climate conditions, South America is one of the most important agricultural regions in the world, providing different kinds of vegetable products to different regions of the world. However, such favorable conditions for plant production also allow the development of several pests, increasing production costs. Among them, whiteflies (Hemiptera: Aleyrodidae) stand out for their potential for infesting several crops and for being resistant to insecticides, having high rates of reproduction and dispersal, besides their efficient activity as virus vectors. Currently, the most important species occurring in South America are Bemisia afer, Trialeurodes vaporariorum, and the cryptic species Middle East-Asia Minor 1, Mediterranean, and New World, from Bemisia tabaci complex. In this review, a series of studies performed in South America were compiled in an attempt to unify the advances that have been developed in whitefly management in this continent. At first, a background of the current whitefly distribution in South American countries as well as factors affecting them are shown, followed by a background of the whitefly transmitted viruses in South America, addressing their location and association with whiteflies in each country. Afterwards, a series of management strategies are proposed to be implemented in South American fields, including cultural practices and biological and chemical control, finalizing with a section containing future perspectives and directions for further research. [ABSTRACT FROM AUTHOR]