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BACKGROUND: Elucidating fitness cost associated with field‐evolved insect resistance to insecticide is of particular importance to current sustainable pest control. The global pest whitefly Bemisia tabaci has developed resistance to many members of neonicotinoids, but little is known about whitefly resistance to neonicotinoid nitenpyram and its associated fitness cost. Using insecticide bioassay and life‐table approach, this study aims to investigate nitenpyram resistance status in field‐collected whitefly populations, and to explore whether such resistance is accompanied by a fitness cost. RESULTS: The bioassay results revealed that 14 of 29 whitefly populations displayed moderate to extremely high resistance to nitenpyram, demonstrating a widespread field‐evolved resistance to nitenpyram. This field‐evolved resistance in the whitefly has increased gradually over the past 3 years from 2021 to 2023. Further life‐table study showed that two resistant whitefly populations exhibited longer developmental time, shorter lifespans of adult, and lower fecundity compared with the most susceptible population. The relative fitness cost of the two resistant populations was calculated as 0.69 and 0.56 by using net productive rate R0, which suggests that nitenpyram resistance comes with fitness cost in the whitefly, especially on reproduction. CONCLUSION: Overall, these results represent field‐evolved high resistance to nitenpyram in the whitefly. The existing fitness costs associated with nitenpyram resistance are helpful to propose a suitable strategy for sustainable control of whiteflies by rotation or mixture of insecticide with different modes of action. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Plant viruses exist in a broader ecological community that includes non-vector herbivores that can impact vector abundance, behavior, and virus transmission within shared host plants. However, little is known about the effects of non-vector herbivore infestation on virus transmission by vector insects on neighboring plants through inter-plant airborne chemicals. In this study, we investigated how volatiles emitted from tomato plants infested with the two-spotted spider mite (Tetranychus urticae) affect the infection of neighboring plants by tomato yellow leaf curl virus (TYLCV) transmitted by whitefly (Bemisia tabaci). Exposure of neighboring tomato plants to volatiles released from T. urticae -infested tomato plants reduced subsequent herbivory as well as TYLCV transmission and infection, and the jasmonic acid signaling pathway was essential for generation of the inter-plant defense signals. We also demonstrated that (E)-β-ocimene and methyl salicylic acid were two volatiles induced by T. urticae that synergistically attenuated TYLCV transmission and infection in tomato. Thus, our findings suggest that plant–plant communication via volatiles likely represents a widespread defensive mechanism that substantially contributes to plant fitness. Understanding such phenomena may help us to predict the occurrence and epidemics of multiple herbivores and viruses in agroecosystems, and ultimately to manage pest and virus outbreaks. [ABSTRACT FROM AUTHOR]

Common bean (Phaseolus vulgaris L.) is a widely cultivated crop, representing an important protein source in the human diet in developing countries. The production of this crop faces serious challenges, such as virus diseases transmitted by the whitefly Bemisia tabaci. Although there is a lot of information about some of these viruses, most of what we know has been developed using model systems, such as tomato plants and tomato yellow leaf curl virus (TYLCV). There is still very little information on the most relevant common bean viruses, such as bean golden mosaic virus (BGMV), bean golden yellow mosaic virus (BGYMV), bean dwarf mosaic virus (BDMV), cowpea mild mottle virus (CPMMV), and bean yellow disorder virus (BnYDV). In this review, we discuss the available data in the most up-to-date literature and suggest future research avenues to contribute to the development of management tools for preventing or reducing the damage caused by viruses in this important crop. [ABSTRACT FROM AUTHOR]

Whitefly, Bemisia tabaci, nymphs and sucking sap adults, is one of the most damaging pests of potato, Solanum tuberosum. Excessive use of pesticides causes environmental pollution and the death of beneficial insects, so it is necessary to search for safer controlling alternatives. An experiment was carried out during seasons 2020–2021 and 2021–2022, under field conditions in Egypt. The objective of this study was to identify the main constituent compounds of peppermint and eucalyptus essential oils prepare coarse emulsion (CE) and nanoemulsion (NE) of both peppermint and eucalyptus essential oils and evaluate their efficiency against the whitefly, B. tabaci, in potato cultivars and the effect of these emulsions on the chemical components of potato leaves. The results revealed that the toxicity of the emulsions decreased with increasing time after spraying. The second spray which took place at a 10-day interval was more effective than the first spray. During the season of 2021, three days following the second spray, the tested emulsions' toxicity was highly effective. The reduction percentages of nymph for peppermint coarse emulsion (PCE), peppermint nanoemulsion (PNE), eucalyptus coarse emulsion (ECE), eucalyptus nanoemulsion (ENE) and imidacloprid were 82.64, 84.14, 73.26, 72.72 and 89.03, but they were 78.58, 83.27, 77.85, 69.97 and 89.26 compared with 2022. A moderately positive correlation was identified between temperature, specific humidity, wind speed and the effectiveness of the emulsions. This indicates that higher levels of temperature, humidity and wind speed were associated with increased efficacy of the emulsions. The study of the phytochemicals (total soluble protein, total carbohydrate, total phenolic contents and peroxidase activity). PCE and ECE achieved a slight decrease in protein levels. Also, ECE increased total plant carbohydrates. All treatments did not affect the phenolic compounds of potato leaf plants except ENE, which caused an increase in phenolic compounds. All treatments decreased the nitrogen plants' contents, while PCE, PNE, and ENE increased the potassium content. All treatments increase the activity of peroxidase (POX) compared with untreated plants. The formulations PNE and ENE might be an interesting alternative for integrated pest management of B. tabaci nymphs. [ABSTRACT FROM AUTHOR]

Cotton leaf curl Multan virus (CLCuMuV), a serious viral disease causative agent in cotton plants in South Asia, is transmitted by the Bemisia tabaci cryptic species complex in a persistent circulative manner. A previous study indicated that Asia II-7 whiteflies could transmit CLCuMuV, while Mediterranean (MED) whiteflies failed to transmit CLCuMuV. However, little is known about the genes involved in this process. In this study, Asia II-7 and MED B. tabaci were utilized to determine transcriptomic responses after 48 h of acquisition access periods (AAPs). Result of Illumina sequencing revealed that, 14,213 and 8,986 differentially expressed genes (DEGs) were identified. Furthermore, DEGs related to the immune system and metabolism of Asia II-7 and MED in response to CLCuMuV-infected plants were identified and analyzed using Gene Ontologies (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG), and the number of related DEGs in MED was lower than that of Asia II-7. The most abundant groups of DEGs between both viruliferous and aviruliferous whitefly species were the zf-C2H2 family of transcription factors (TFs). Notably, in comparison to viruliferous MED, Asia II-7 exhibited more DEGs related to cathepsin biosynthesis. Overall, this study provides the basic information for investigating the molecular mechanism of how begomoviruses affect B. tabaci metabolism and immune response either as vector cryptic species or non-vector species. [ABSTRACT FROM AUTHOR]

This method of planting is developing in the United States and according to the obtained reports, it has saved water consumption, reduced the cost of weeding, increased production and maturity, and reduced the population of pests and damage to cotton. The advantages of this planting method include increasing maturity as well as crop yield. To investigate this issue in Golestan province, some important studies such as the effect of pix material, different fertilizers, pests and diseases and irrigation in planting very narrow row spacing were evaluated over two years. This experiment is to examine and compare the population of cotton whiteflies on 3 cluster cultivars and one control, using the method of narrow planting distance of 20 × 20 and 20 × 80 cm as a factorial design in the form of an RCBD with 3 replications in Hashemabad cotton research station in Gorgan during two years 2018-2019 was evaluated. Statistics of different stages of cotton whitefly pest were recorded weekly in the tested treatments and recorded in special tables. Based on the studies, the results of the combined analysis of variance showed that the yield in the cultivars tested in the Sajedi cultivar with a distance of 80 cm with an average wash of 1696 gr in the plot and Golestan® cultivar 80 cm with 1622.9 gr in the plot with the highest yield and cultivar T2 with a distance of 20 cm, 847.2 gr had the lowest yield in the plot. Infestation rate of cluster cultivars tested in very narrow cultivation of whitefly population density on Golestan® cultivars with a distance of 80 cm, Sajedi with a distance of 20 cm with 65.50 and 57.75 whitefly in the leaves had the highest infestation, respectively, and on Sajedi cultivars with a distance of 80 cm with a density of 46.75 whitefly on the leaves had the least infestation. [ABSTRACT FROM AUTHOR]

Simple Summary: Bemisia tabaci is as a major pest of vegetable crops in Cameroon, and several species have developed resistance against insecticides. Here, we investigated the frequency of infection by endosymbiont and the genetic diversity of whiteflies in Cameroon. Mitochondrial cytochrome oxidase I (mtCOI) markers and Kompetitive Allele Specific PCR (KASP) were used for the characterization. Overall, an analysis of the mtCOI sequences showed six mitotypes of Bemisia tabaci, and two distinct clades of Bemisia afer and Trialeurodes vaporariorum. Bemisia tabaci mitotypes identified included: Mediterranean (MED) on tomato, pepper, okra, and melon; and sub-Saharan Africa (SSA) groups and sub-groups (SG)–SSA1-SG1, SSA1-SG2, SSA1-SG5, SSA3, and SSA4 on cassava. The six mitotypes of cassava B. tabaci were split into three SNP haplogroups including sub-Saharan Africa–West Africa (SSA-WA), sub-Saharan East and Central Africa (SSA-ECA), and SSA4 by KASP genotyping. The endosymbionts identified infecting the whiteflies were Arsenophonus, Rickettsia, and Wolbachia. Bemisia tabaci (Gennadius) is as a major pest of vegetable crops in Cameroon. These sap-sucking insects are the main vector of many viruses infecting plants, and several cryptic species have developed resistance against insecticides. Nevertheless, there is very little information about whitefly species on vegetable crops and the endosymbionts that infect them in Cameroon. Here, we investigated the genetic diversity of whiteflies and their frequency of infection by endosymbionts in Cameroon. Ninety-two whitefly samples were collected and characterized using mitochondrial cytochrome oxidase I (mtCOI) markers and Kompetitive Allele Specific PCR (KASP). The analysis of mtCOI sequences of whiteflies indicated the presence of six cryptic species (mitotypes) of Bemisia tabaci, and two distinct clades of Bemisia afer and Trialeurodes vaporariorum. Bemisia tabaci mitotypes identified included: MED on tomato, pepper, okra, and melon; and SSA1-SG1, SSA1-SG2, SSA1-SG5, SSA3, and SSA4 on cassava. The MED mitotype predominated in all regions on the solanaceous crops, suggesting that MED is probably the main phytovirus vector in Cameroonian vegetable cropping systems. The more diverse cassava-colonizing B. tabaci were split into three haplogroups (SNP-based grouping) including SSA-WA, SSA4, and SSA-ECA using KASP genotyping. This is the first time that SSA-ECA has been reported in Cameroon. This haplogroup is predominant in regions currently affected by the severe cassava mosaic virus disease (CMD) and cassava brown streak virus disease (CBSD) pandemics. Three endosymbionts including Arsenophonus, Rickettsia, and Wolbachia were present in female whiteflies tested in this study with varying frequency. Arsenophonus, which has been shown to influence the adaptability of whiteflies, was more frequent in the MED mitotype (75%). Cardinium and Hamiltonella were absent in all whitefly samples. These findings add to the knowledge on the diversity of whiteflies and their associated endosymbionts, which, when combined, influence virus epidemics and responses to whitefly control measures, especially insecticides. [ABSTRACT FROM AUTHOR]

Cassava is an important food crop in western Kenya, yet its production is challenged by pests and diseases that require routine monitoring to guide development and deployment of control strategies. Field surveys were conducted in 2022 and 2023 to determine the prevalence, incidence and severity of cassava mosaic disease (CMD) and cassava brown streak disease (CBSD), whitefly numbers and incidence of cassava green mite (CGM) in six counties of western Kenya. Details of the encountered cassava varieties were carefully recorded to determine the adoption of improved varieties. A total of 29 varieties were recorded, out of which 13 were improved, although the improved varieties were predominant in 60% of fields and the most widely grown variety was MM96/4271. The CMD incidence was higher in 2022 (26.4%) compared to 2023 (10.1%), although the proportion of CMD attributable to whitefly infection was greater (50.6%) in 2023 than in 2022 (18.0%). The CBSD incidence in 2022 was 6.4%, while in 2023 it was 4.1%. The CMD incidence was significantly lower (5.9%) for the improved varieties than it was for the local varieties (35.9%), although the CBSD incidence did not differ significantly between the improved (2.3%) and local varieties (9.7%). Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV) were both detected. Most infections were single CBSV infections (82.9%), followed by single UCBSV (34.3%) and coinfection with both viruses (16.7%). Whiteflies were more abundant in 2023, in which 28% of the fields had super-abundant populations of >100/plant, compared to 5% in 2022. KASP SNP genotyping designated 92.8% of the specimens as SSA-ECA for 2022, while it was 94.4% for 2023. The cassava green mite incidence was 65.4% in 2022 compared to 79.9% in 2023. This study demonstrates that cassava viruses, whiteflies and cassava green mites continue to be important constraints to cassava production in western Kenya, although the widespread cultivation of improved varieties is reducing the impact of cassava viruses. The more widespread application of high-quality seed delivery mechanisms could further enhance the management of these pests/diseases, coupled with wider application of IPM measures for whiteflies and mites. [ABSTRACT FROM AUTHOR]

To clarify the predation potential of Orius sauteri on the nymphs of Bemisia tabaci, the preference of the 5th instar nymphs and female adults of O. sauteri for the 2nd-4th instar nymphs of B. tabaci, the predation ability of O. sauteri on the 4th instar nymphs of B. tabaci, and the interference effect of different O. sauteri density on the predation of B. tabaci were investigated under indoor conditions. The results indicated that O. sauteri showed a negative preference for both the 2nd and 3rd instar nymphs of B. tabaci, while exhibiting a positive preference for the 4th instar nymphs of B. tabaci. The daily predation rates of the 5th instar nymphs and female adults of O. sauteri on the 4th instar nymphs of B. tabaci were 14.00 and 16.00, respectively, with instantaneous attack rates of 0.878 and 0.888, and handling time per B. tabaci of 0.047 and 0.034 days, respectively. The predatory ability of female O. sauteri adults was superior to that of the 5th instar nymphs. The daily predation rate of O. sauteri positively correlated with the density of B. tabaci but negatively correlated with its searching efficiency. The predation rate of O. sauteri decreased with the increase in its own density. [ABSTRACT FROM AUTHOR]

Abstract In many insects the surface of the eye is nanostructured by arrays of protuberances termed ommatidial gratings which provide the cuticle with anti-reflective, anti-wetting and self-cleaning properties. The hypothesised anti-contamination role of the gratings against dust and pollen results from theoretical predictions on grating geometry and experiments on synthetic replicas of ommatidia surfaces but has not yet been proven in an animal. Whiteflies are biological test beds for anti-contamination surfaces because they deliberately distribute wax particles extruded from abdominal plates over their entire bodies. The numerous particles protect the animal against water evaporation and radiation, but may severely impair vision. Using scanning electron microscopy (SEM) and CryoSEM, we here show that the cornea of whiteflies exhibits ~ 220 nm wide mesh-like structures forming hexagonal gratings with thin ~ 40 nm connecting walls. Quantitative measurements of wax particles on the eye show that the nanostructures reduce particle contamination by more than ~ 96% compared to other areas of the cuticle. Altogether, our study is the first description of a predicted optimized grating geometry for anti-contamination in an arthropod. The findings serve as evidence of the high effectiveness of nanostructured surfaces for reducing contact area and thus adhesion forces between biological surfaces and contaminating particles.

Bemisia tabaci is one of the limiting factors in chili farming, because it can cause damage both directly and indirectly as a vector for the Pepper yellow leaf curl virus (PepYLCV). Intercropping chili with corn is one of the efforts to control B. tabaci. Physically, corn plants are able to withstand the presence of B. tabaci, in addition to producing volatile compounds that are repellent to B. tabaci. This research was conducted to determine the optimal age of corn plants to be intercropped with chili plants. The research was conducted in Pleret District, Bantul Regency by testing five different ages of corn: 2 weeks after planting, 6 weeks after planting, 8 weeks after planting, 10 weeks after planting and control (without intercropping with corn). Weeks after planting are counted from the first day the corn seeds were planted. Yellow sticky trap (YST) was used to determine the presence of B. tabaci population in each treatment plot. YST was tied to bamboo sticks and placed on treatment beds with as many as 2 (two) traps per treatment plot. The distance between the yellow sticky trap and the plant was 30 cm, so the height of the trap was always adjusted according to the height of the plant. Observation of B. tabaci population was carried out every 5 days by counting the number of B. tabaci caught in yellow sticky traps. The results showed that the population of B. tabaci in the chili plots intercropped with corn was lower than that in the control plot, especially at the age of 6 weeks after planting (WAP). However, the intercropping of chilies and corn had no significant effect on the incidence of yellow disease in chilies.

Abstract The cotton whitefly, Bemisia tabaci, is considered as a species complex with 46 cryptic species, with Asia II-1 being predominant in Asia. This study addresses a significant knowledge gap in the characterization of odorant-binding proteins (OBPs) and chemosensory proteins (CSPs) in Asia II-1. We explored the expression patterns of OBPs and CSPs throughout their developmental stages and compared the motif patterns of these proteins. Significant differences in expression patterns were observed for the 14 OBPs and 14 CSPs of B. tabaci Asia II-1, with OBP8 and CSP4 showing higher expression across the developmental stages. Phylogenetic analysis reveals that OBP8 and CSP4 form distinct clades, with OBP8 appearing to be an ancestral gene, giving rise to the evolution of other odorant-binding proteins in B. tabaci. The genomic distribution of OBPs and CSPs highlights gene clustering on the chromosomes, suggesting functional conservation and evolutionary events following the birth-and-death model. Molecular docking studies indicate strong binding affinities of OBP8 and CSP4 with various odour compounds like β-caryophyllene, α-pinene, β-pinene and limonene, reinforcing their roles in host recognition and reproductive functions. This study elaborates on our understanding of the putative roles of different OBPs and CSPs in B. tabaci Asia II-1, hitherto unexplored. The dynamics of the expression of OBPs and CSPs and their interactions with odour compounds offer scope for developing innovative methods for controlling this global invasive pest.

Whitefly (Bemisia tabaci Gennadius) (Hemiptera: Aleyrodidae) is a serious pest of several summer crops in hot and dry climates with diverse cryptic species complex worldwide. Cotton is one of the favorite hosts of B. tabaci, where it feeds and spread different plant viruses. The major clade of B. tabaci; Asia-II is predominant in the cotton zone of Punjab-Pakistan. The control of B. tabaci in cotton ecosystem mostly depends upon the sprays of synthetic insecticides in Pakistan. Monitoring of insecticidal resistance is an essential tool in effective management of B. tabaci. Different cotton field strains were collected from the four major cotton growing districts of South Punjab to assess their genetic mitotype and resistance levels compared with the laboratory susceptible population against most commonly used insecticides during 2020 and 2021. Leaf-dip bioassays were performed on 2nd instar nymphal (N2) stage; while adult bioassays were conducted on field collected populations. Genetic analysis of mtCOI revealed that all the populations were belonged to Asia II-1 clade. A mixture of three haplotypes of Asia II-I including haplotypes-2, haplotype-3 and haplotype-4 was identified from Jampur and Bahawalpur samples. However, haplotype-4 and haplotype-3 were identified from Multan population while Vehari samples comprised of haplotype-4 and haplotype-2. Buprofezin (RR ranged 25.75–36.71), pyriproxyfen (RR ranged 7.98–12.78) and diafenthiuron (RR ranged 20.59–28.12) were least efficient products in adult bioassays and had moderate to low level of resistance. However, spirotetramat and flonicamid both were relatively effective against adults with low to very low resistance during both the years. Pyriproxyfen demonstrated least efficacy for reducing adult emergence followed by flonicamid and buprofezin with moderate to very low resistance ratio respectively. In contrast spirotetramat (RR ranged 2.20–4.01), was highly effective against nymphs followed by diafenthiuron (RR ranged 4.63–7.68), having very low resistance ratio. However an upward trend of resistance development was observed against all the five tested insecticides during both the monitoring years. It can be concluded that, in the aftermath of the emergence of resistance to old conventional insecticides, various chemistries with unique modes of action having no, very low, or low levels of resistance can be substituted in rotation. [ABSTRACT FROM AUTHOR]

The tobacco whitefly, Bemisia tabaci MEAM1, is a destructive pest that damages plants by sucking plant juice and transmitting viruses. B. tabaci insecticide resistance contributes to population resurgence, and new insecticides are continually needed. Flonicamid and afidopyropen are selective pesticides with high insecticidal activity against piercing–sucking pests and safety to non-target species. We determined the toxicity of flonicamid and afidopyropen to B. tabaci, investigated the sublethal effects on life parameters, and studied physiological responses to them. Flonicamid and afidopyropen were highly toxic to B. tabaci, with LC50 values of 12.795 mg/L (afidopyropen) and 25.359 mg/L (flonicamid) to nymphs and 4.711 mg/L (afidopyropen) and 11.050 mg/L (flonicamid) to adults. Sublethal concentrations (LC10 and LC20) reduced the longevity and fecundity of the B. tabaci F0 generation. Transgenerational effects were caused by exposure to sublethal concentrations of flonicamid and afidopyropen. Nymph mortality increased, development was delayed, fecundity decreased, and adult longevity was shortened. Population parameters such as the intrinsic rate of growth (r), net reproductive rate (R0), and finite rate of growth (λ) were significantly decreased compared to the control. The activity of detoxifying enzymes, such as GSTs and P450, were induced by flonicamid and afidopyropen at 72 h, while CarE was inhibited. The expression levels of eleven P450 genes and four GST genes were significantly higher than in the control. In conclusion, flonicamid and afidopyropen have excellent acute toxicity and continuous control effects on B. tabaci. Higher GST and P450 activities and gene expression levels may play important roles in the detoxification metabolic process. [ABSTRACT FROM AUTHOR]

Although cowpea mild mottle virus (CPMMV) has been reported in Brazil since 1983, it has only become a significant concern for researchers and farmers in recent years. The objective of this work was to investigate the genetic basis of CPMMV tolerance, mapping and reporting the first loci associated with this trait in common bean (cv. BRS Sublime). Phenotypic assays were carried out on 180 individual plants (F2 generation) and 180 F2:3 progenies comprising 12 plants per family and their parents (BRS Sublime, tolerant parent × CNFCT 16207, susceptible parent). CPMMV was mechanically inoculated and symptoms were evaluated at 35 days after inoculation, using a 1–5 scoring scale. A linkage map was constructed using 1695 single‐nucleotide polymorphism (SNP) and SilicoDArT markers that segregated in the F2 and F2:3 generations as expected. Markers were distributed across 11 common bean chromosomes, resulting in a total length of 2864 cM, with an average distance between markers of 1.8 cM. Phenotypic observations revealed that tolerance in cv. BRS Sublime is controlled by a single dominant gene. The main effect quantitative trait locus (QTL; CPMMV.Pv08) associated with CPMMV tolerance was identified in the terminal region on chromosome 8 (Pv08). This QTL explained approximately 77% of phenotypic variation, indicating that the inheritance of tolerance to CPMMV is monogenic, controlled by a major locus. As far as we know, this study represents the first investigation into the inheritance and genetic mapping of CPMMV tolerance in common bean, with potential for the development of elite lines with multiple virus resistance/tolerance. [ABSTRACT FROM AUTHOR]

The whitefly Bemisia tabaci (Gennadius) has coevolved with intracellular endosymbiotic bacteria that help supplement their nutrient-poor diets with essential amino acids and carotenoids; however the type of host species and the agricultural practices can influence the composition of the endosymbiotic bacterial community. In this study, the main goal was to explore the diversity of endosymbiont communities in whitefly populations growing in peppers (Capsicum chinense Jacq. under greenhouse and Capsicum annuum L. backyard) exposed to chemical insecticides (treatment MB1) and non-exposed (treatment MB2). The whiteflies were identified through phylogenetic analysis of the mitochondrial Cytochrome Oxidase I gene sequences. Bacterial endosymbionts were characterized by high-throughput sequencing of the V3 region of the 16S rRNA gene, which amplifies a fragment of around 180 bp. Sequence analysis yielded in MB1 eight Phylum, nine classes, 30 orders, 35 families, 64 genera, and 20 species, while in MB2 it was obtained eight Phylum, 11 classes, 26 orders, 37 families, 61 genera, and 18 species. The most abundant phylum in the two samples analyzed was Proteobacteria followed by Chlamydiae and Bacteroidetes. The phyla that presented the greatest taxonomic diversity of bacteria at the genus level in both samples were Proteobacteria, Actinobacteria and Firmicutes. According to the evaluated alpha diversity indices, low richness and diversity were obtained in the two samples, but when comparing the two samples, MB2 showed the greatest richness and diversity with 1,698 with the Shannon index.. The results obtained are a first approximation to describe the impact of insecticides used on peppers on the diversity and richness of whitefly endosymbiotic bacteria. [ABSTRACT FROM AUTHOR]

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Summary: RNA interference (RNAi) has emerged as an efficient technology for pest control by silencing the essential genes of targeted insects. Owing to its nucleotide sequence‐guided working mechanism, RNAi has a high degree of species‐specificity without impacts on non‐target organisms. However, as plants are inevitably under threat by two or more insect pests in nature, the species‐specific mode of RNAi‐based technology restricts its wide application for pest control. In this study, we artificially designed an intermediate dsRNA (iACT) targeting two β‐Actin (ACT) genes of sap‐sucking pests Bemisia tabaci and Myzus persicae by mutual correction of their mismatches. When expressing hairpin iACT (hpiACT) from tobacco nuclear genome, transgenic plants are well protected from both B. tabaci and M. persicae, either individually or simultaneously, as evidenced by reduced fecundity and suppressed ACT gene expression, whereas expression of hpRNA targeting BtACT or MpACT in transgenic tobacco plants could only confer specific resistance to either B. tabaci or M. persicae, respectively. In sum, our data provide a novel proof‐of‐concept that two different insect species could be simultaneously controlled by artificial synthesis of dsRNA with sequence optimization, which expands the range of transgenic RNAi methods for crop protection. [ABSTRACT FROM AUTHOR]

BACKGROUND: Temperature is a primary factor that determines the eco‐geographical distribution and population development of invasive insects. Temperature stress leads to various negative effects, including excess reactive oxygen species (ROS), and catalase (CAT) is a key enzyme against ROS in the antioxidant pathway. The whitefly Bemisia tabaci MED is a typical invasive pest that causes damage worldwide. Our previous studies have shown that CAT promotes whitefly adaptation to high temperature by eliminating ROS. However, the mechanism underlying the low‐temperature adaptation of whiteflies is still unknown. RESULTS: In this study, we investigated the role of CAT in the low‐temperature tolerance of B. tabaci MED by analyzing its survival rate, reproduction, and ROS levels at 25 °C (as a control, suitable temperature), 20 °C (moderately decreased temperature), and 4 °C (severely decreased temperature). Silencing of BtCAT1, BtCAT2, or BtCAT3 reduced the viability of whiteflies under a short‐term severely decreased temperature (4 °C), which manifested as decreases in survival and fecundity accompanied by significant increases in ROS levels. Moreover, even at a moderately decreased temperature (20 °C), silencing of BtCAT1 led to high ROS levels and low survival rates in adults. CONCLUSION: Silencing of BtCATs significantly increased the sensitivity of B. tabaci MED to low temperatures. BtCAT1 is likely more essential than other BtCATs for low‐temperature tolerance in whiteflies. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

In tropical countries, combating leaf curl disease in hot peppers has become important in improvement programs. Leaf curl disease is caused by whitefly (Bemisia tabaci) transmitted begomoviruses, which mainly include chilli leaf curl virus (ChiLCV). However, multiple begomoviruses have also been found to be associated with this disease. The Capsicum annuum line, DLS-Sel-10, was found to be a tolerant source against this disease during field screening. In this study, we characterized the resistance of DLS-sel-10 against chilli leaf curl virus (ChiLCV) in comparison to the susceptible cultivar Phule Mukta (PM), focusing on the level, stage, and nature of resistance. Comprehensive investigations involved screening of DLS-Sel-10 against the whitefly vector ChiLCV. The putative tolerant line displayed reduced virus infection at the seedling stage, with increasing resistance during vegetative, flowering, and fruiting stages. Both DLS-Sel-10 and PM could be infected with ChiLCV, although DLS-Sel-10 remained symptomless. Insect feeding assays revealed DLS-Sel-10 as a less preferred host for whiteflies compared to PM. In conclusion, DLS-Sel-10 demonstrated tolerance not only to ChiLCV but also served as an unfavorable host for the whitefly vector. The study highlighted an age-dependent increase in tolerance within DLS-Sel-10, showcasing its potential for effective leaf curl disease management in chilli. [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: Bemisia tabaci (Gennadius) is a worldwide agricultural pest and is one of the most harmful invasive insect pests in the world. The overuse of insecticides has caused B. tabaci to develop high resistance against multiple insecticidal chemicals. It is well recognized that over-expression of cytochrome P450s involved in insecticide detoxification is one common and major mechanism of resistance to various classes of insecticides in insects. In addition to gene duplication and amplification, up-regulation of P450s at the transcriptional level is a common and important mechanism for P450-mediated insecticide resistance. Here, two new CYP450 genes from B. tabaci MEAM1 were cloned, and their expression patterns were studied in response to two different insecticides, high temperature, and their combined effects. The results showed that the insecticide tolerance could be reduced by high temperatures; under combined stress, the mortality of B. tabaci MEAM1 increased. This study is an important addition to the research on insecticide tolerance in B. tabaci and may help to reduce the overreliance on insecticides for B. tabaci control. Bemisia tabaci (Gennadius) is one of the most important invasive species in China, with strong insecticide resistance and thermotolerance. In this study, we investigated the effects of elevated temperature on the tolerance of B. tabaci MEMA1 to abamectin (AB) and thianethixam (TH) insecticides. We firstly cloned two new CYP450 genes from B. tabaci MEAM1, including one CYP6 family gene (BtCYP6k1) and one CYP305 family gene (BtCYP305a1). The expression patterns of the two BtCYP450 genes were compared in response to high-temperature stress and insecticide exposure, and RNAi was then used to demonstrate the role that these two genes play in insecticide tolerance. The results showed that expression of the two BtCYP450 genes could be induced by exposure to elevated temperature or insecticide, but this gene expression could be inhibited to a certain extent when insects were exposed to the combined effects of high temperature and insecticide treatment. For AB treatment, the expression of the two BtCYP450 genes reached the lowest level when insects were exposed to a temperature of 41 °C and treated with AB (combined effects of temperature and insecticide). In contrast, TH treatment showed a general decrease in the expression of the two BtCYP450 genes with exposure to elevated temperatures. These findings suggest that insecticide tolerance in B. tabaci MEAM1 could be mediated by high temperatures. This study provides a prospective method for the more effective application of insecticides for the control of B. tabaci in the field. [ABSTRACT FROM AUTHOR]

Bemisia tabaci poses a major threat to tomato crops, causing significant yield losses and economic damage to farmers. This study investigates the conidia filtration method as a potential management strategy for B. tabaci under greenhouse conditions. Evaluating the efficacy of this approach in controlling the whitefly population while potentially promoting plant growth is crucial for developing sustainable solutions for tomato production. Both Trichoderma viride and Beauveria bassiana fungi effectively killed adult whiteflies in this study, significantly exceeding the untreated control. Beauveria bassiana showed slightly higher mortality rates at all time points, achieving a maximum of 69.47% compared to T. viride's 62.22% after 14 days. Trichoderma viride and Beauveria bassiana significantly stimulated plant growth compared to the untreated control. However, T. viride emerged as the superior growth promoter across all assessed parameters: plant height, fresh weight, and dry weight. It achieved the tallest plants (27.31 cm), exceeding both the control and B. bassiana. Similarly, its impact on fresh and dry weight surpassed both the control and B. bassiana, reaching respective values of 14.21 and 2.83 g. These findings suggest that T. viride holds greater potential as a plant growth promoter under the examined conditions. [ABSTRACT FROM AUTHOR]

Abstract Piercing sucking pests are destructive to many strategic crops all over the world. Botanical pesticides can be used to control these pests. A new withanolide derivative 3 named sominone A ((20R,22R)-1α,3β,20,27-tetrahydroxywitha-5,24-dienolide) was isolated from the alkaloid fraction of the whole plant of Withania somnifera. In addition, there are three known compounds named withasomine 1, methyl isoferulate 2, and coagulin Q 4 were also isolated. The structures of isolated compounds were identified using different spectroscopic methods such as 1D, 2D NMR, and HRESIMS spectroscopy. The alkaloid fraction and the four isolated compounds were tested for their pesticidal activity against four piercing sucking pests (Aphis craccivora Koch, Bemisia tabaci Gennadius, Nezara viridula Linnaeus, and Tetranychus urticae Koch) that attack many strategic crops under laboratory conditions, along with azadirachtin (Okios 3.2% EC) as a positive control. The results showed that the alkaloid compound (withasomine 1) was the most toxic to A. craccivora, B. tabaci, N. viridula, and T. urticae, with LC50 values of 15.44, 36.61, 85.11, and 128.28 ppm, respectively, compared with the control. Withanolide compounds had moderate effects on all tested pests. Biochemical parameters of six enzymes; α-esterase, β-esterase, chitinase, acetylcholinesterase, glutathione-S-transferase, and peroxidase of A. craccivora were estimated at the LC50 value of the most potent compound, withasomine 1 and the values were 38.83, 72.86, 31.45, 506.4, 2.62, and 251.0, respectively. The results demonstrated that all enzymes activity levels were increased compared with the control except a remarkable inhibition in AChE enzyme level was observed compared with control. Therefore, the alkaloid fraction of W. somnifera is a promising extract that contains many active compounds that can be used as a natural pesticide against many harmful pests in agriculture crops. Graphical Abstract

Plant fertilization may impact directly on insect pest behavior and biology. Fertilization may be accomplished by using synthetic mineral or organic fertilizers. The effect of different doses of boiled hen chicken manure, Penergetic®, Bokashi compound and mineral fertilizer on the adult population of Bemisia tabaci and Myzus persicae on collards leaves were evaluated. The experiment was conducted in the greenhouse using the treatments: Bokashi, Penergetic® bioactivator, 2.5%, 5%, and 7.5% of solution of boiled manure, mineral fertilization and control. The number of insects was counted directly on the leaves, and the nitrogen, potassium content, and total phenolic compound in the leaves were determined. Higher populations of Bemisia tabaci and M. persicae were observed on NPK-fertilized plants compared to other treatments. Higher levels of nitrogen foliar were found for Bokashi-fertilized plants; and higher concentrations of total phenolic compounds were found in the control. A negative correlation between total phenolics and B. tabaci was established suggesting the importance of these compounds in the species development. The results indicate the importance of the source of the fertilization for sustainable pest management. [ABSTRACT FROM AUTHOR]

Bemisia tabaci is an important agricultural pest that has been causing significant economic losses to crops across the globe. Destruxins are secondary metabolites of entomopathogenic fungi which can be used as a potential biopesticide against B. tabaci. However, little is known about the molecular mechanism involved in the regulation of the immune response of B. tabaci post-destruxin application. In this study, we explored the molecular responses of B. tabaci exposed to destruxin A (DA) using RNA-Seq. A total of 1702, 616, and 555 differentially expressed genes (DEGs) were identified in B. tabaci after 4, 8, and 12 h of DA treatment. In addition, 39 putative detoxification-related DEGs including 29 cytochrome P450s (P450s), 5 glutathione S-transferases (GSTs), and 5 carboxylesterases (CarEs) were also identified. Quantitative real-time PCR analysis indicated that the expression profiles of 19 random DEGs were consistent with the RNA-Seq results. These findings serve as valuable information for a better understanding of the interaction and molecular mechanisms involved in the defense response of B. tabaci against DA. [ABSTRACT FROM AUTHOR]

Cassava (Manihot esculenta) is among the most important staple crops globally, with an imperative role in supporting the Sustainable Development Goal of 'Zero hunger'. In sub-Saharan Africa, it is cultivated mainly by millions of subsistence farmers who depend directly on it for their socio-economic welfare. However, its yield in some regions has been threatened by several diseases, especially the cassava brown streak disease (CBSD). Changes in climatic conditions enhance the risk of the disease spreading to other planting regions. Here, we characterise the current and future distribution of cassava, CBSD and whitefly Bemisia tabaci species complex in Africa, using an ensemble of four species distribution models (SDMs): boosted regression trees, maximum entropy, generalised additive model, and multivariate adaptive regression splines, together with 28 environmental covariates. We collected 1,422 and 1,169 occurrence records for cassava and Bemisia tabaci species complex from the Global Biodiversity Information Facility and 750 CBSD occurrence records from published literature and systematic surveys in East Africa. Our results identified isothermality as having the highest contribution to the current distribution of cassava, while elevation was the top predictor of the current distribution of Bemisia tabaci species complex. Cassava harvested area and precipitation of the driest month contributed the most to explain the current distribution of CBSD outbreaks. The geographic distributions of these target species are also expected to shift under climate projection scenarios for two mid-century periods (2041–2060 and 2061–2080). Our results indicate that major cassava producers, like Cameron, Ivory Coast, Ghana, and Nigeria, are at greater risk of invasion of CBSD. These results highlight the need for firmer agricultural management and climate-change mitigation actions in Africa to combat new outbreaks and to contain the spread of CBSD. [ABSTRACT FROM AUTHOR]

Plants can respond to insect infestation and virus infection by inducing plant defenses, generally mediated by phytohormones. Moreover, plant defenses alter host quality for insect vectors with consequences for the spread of viruses. In agricultural settings, other organisms commonly interact with plants, thereby inducing plant defenses that could affect plant–virus–vector interactions. For example, plant defenses induced by omnivorous insects can modulate insect behavior. This study focused on tomato yellow leaf curl virus (TYLCV), a plant virus of the family Geminiviridae and genus Begomovirus. It is transmitted in a persistent circulative manner by the whitefly Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae), posing a global threat to tomato production. Mirids (Hemiptera: Miridae) are effective biological control agents of B. tabaci, but there is a possibility that their omnivorous nature could also interfere with the process of virus transmission. To test this hypothesis, this study first addressed to what extent the mirid bug Dicyphus hesperus Knight induces plant defenses in tomato. Subsequently, the impact of this plant–omnivore interaction on the transmission of TYLCV was evaluated. Controlled cage experiments were performed in a greenhouse setting to evaluate the impact of mirids on virus transmission and vector acquisition by B. tabaci. While we observed a reduced number of whiteflies settling on plants exposed to D. hesperus, the plant defenses induced by the mirid bug did not affect TYLCV transmission and accumulation. Additionally, whiteflies were able to acquire comparable amounts of TYLCV on mirid-exposed plants and control plants. Overall, the induction of plant defenses by D. hesperus did not influence TYLCV transmission by whiteflies on tomato. [ABSTRACT FROM AUTHOR]

Identifying cryptic species poses a substantial challenge to both biologists and naturalists due to morphological similarities. Bemisia tabaci is a cryptic species complex containing more than 44 putative species; several of which are currently among the world's most destructive crop pests. Interpreting and delimiting the evolution of this species complex has proved problematic. To develop a comprehensive framework for species delimitation and identification, we evaluated the performance of distinct data sources both individually and in combination among numerous samples of the B. tabaci species complex acquired worldwide. Distinct datasets include full mitogenomes, single‐copy nuclear genes, restriction site‐associated DNA sequencing, geographic range, host speciation, and reproductive compatibility datasets. Phylogenetically, our well‐supported topologies generated from three dense molecular markers highlighted the evolutionary divergence of species of the B. tabaci complex and suggested that the nuclear markers serve as a more accurate representation of B. tabaci species diversity. Reproductive compatibility datasets facilitated the identification of at least 17 different cryptic species within our samples. Native geographic range information provides a complementary assessment of species recognition, while the host range datasets provide low rate of delimiting resolution. We further summarized different data performances in species classification when compared with reproductive compatibility, indicating that combination of mtCOI divergence, nuclear markers, geographic range provide a complementary assessment of species recognition. Finally, we represent a model for understanding and untangling the cryptic species complexes based on the evidence from this study and previously published articles. [ABSTRACT FROM AUTHOR]

Phytosanitary management on tomato crop is a challenge for organic and conventional growers. Whitefly Bemisia tabaci (Gennadius) and mite Tetranychus evansi Baker and Pritchard are among the major pests. Methyl-salicylate (MeSa) is a methyl ester from salicylic acid and activates secondary metabolism pathways in plants. Zingiberene (ZGB) is a secondary compound associated with resistance to B. tabaci. The aim of the study was to study the relationship between the exogenous MeSA spraying and zingiberene content in tomato leaves and adult whitefly and mite responses. MeSa concentrations [0 (control), 100, 200, 300, 400, 500 µg L−1)] were applied on tomato to evaluate the ZGB content and the relationship with whitefly and spider mite on plants. After the last ZGB analysis, plants were placed in B. tabaci-highly infested greenhouse. The number of adult whiteflies on plants was determined three days later. Tomato leaflets were collected from treated plants and infested with five T. evansi e females. The number of larvae emerging from eggs was evaluated after 96 and 120 h. Reduction of adult whiteflies (from 78 to 8%) was also observed in plants exogenously treated with MeSa [significant and negative correlation (0.88)]. The number of eggs and number of larvae were linearly reduced with increase of MeSa concentration. Positive correlation (0.97) between exogenous MeSa concentrations vs. ZGB contents was observed. Negative correlations (0.90, 0.89 and 0.94) were estimated, between MeSa concentration vs. tomato red spider mite oviposition and egg hatchability (96 and 120 h), respectively. These results indicate that exogenous MeSa applications increases ZGB content and plant resistance to B. tabaci and T. evansi. [ABSTRACT FROM AUTHOR]

Polyunsaturated fatty acids (PUFAs) are essential nutrients for all living organisms. PUFA synthesis is mediated by Δ12 desaturases in plants and microorganisms, whereas animals usually obtain PUFAs through their diet. The whitefly Bemisia tabaci is an extremely polyphagous agricultural pest that feeds on phloem sap of many plants that do not always provide them with sufficient PUFAs. Here, a plant‐derived Δ12 desaturase gene family BtFAD2 is characterized in B. tabaci and it shows that the BtFAD2‐9 gene enables the pest to synthesize PUFAs, thereby significantly enhancing its fecundity. The role of BtFAD2‐9 in reproduction is further confirmed by transferring the gene to Drosophila melanogaster, which also increases the fruit fly's reproduction. These findings reveal an extraordinary evolutionary scenario whereby a phytophagous insect acquired a family of plant genes that enables it to synthesize essential nutrients, thereby lessening its nutritional dependency and allowing it to feed and reproduce on many host plants. [ABSTRACT FROM AUTHOR]

Piercing sucking pests are destructive to many strategic crops all over the world. Botanical pesticides can be used to control these pests. A new withanolide derivative 3 named sominone A ((20R,22R)-1α,3β,20,27-tetrahydroxywitha-5,24-dienolide) was isolated from the alkaloid fraction of the whole plant of Withania somnifera. In addition, there are three known compounds named withasomine 1, methyl isoferulate 2, and coagulin Q 4 were also isolated. The structures of isolated compounds were identified using different spectroscopic methods such as 1D, 2D NMR, and HRESIMS spectroscopy. The alkaloid fraction and the four isolated compounds were tested for their pesticidal activity against four piercing sucking pests (Aphis craccivora Koch, Bemisia tabaci Gennadius, Nezara viridula Linnaeus, and Tetranychus urticae Koch) that attack many strategic crops under laboratory conditions, along with azadirachtin (Okios 3.2% EC) as a positive control. The results showed that the alkaloid compound (withasomine 1) was the most toxic to A. craccivora, B. tabaci, N. viridula, and T. urticae, with LC50 values of 15.44, 36.61, 85.11, and 128.28 ppm, respectively, compared with the control. Withanolide compounds had moderate effects on all tested pests. Biochemical parameters of six enzymes; α-esterase, β-esterase, chitinase, acetylcholinesterase, glutathione-S-transferase, and peroxidase of A. craccivora were estimated at the LC50 value of the most potent compound, withasomine 1 and the values were 38.83, 72.86, 31.45, 506.4, 2.62, and 251.0, respectively. The results demonstrated that all enzymes activity levels were increased compared with the control except a remarkable inhibition in AChE enzyme level was observed compared with control. Therefore, the alkaloid fraction of W. somnifera is a promising extract that contains many active compounds that can be used as a natural pesticide against many harmful pests in agriculture crops. [ABSTRACT FROM AUTHOR]

Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is one of the most economically significant and widely distributed whitefly species. Encarsia lutea Masi (Hymenoptera: Aphelinidae) is a heteronomous hyperparasitoid and is reported to be one of the key factors in the management of B. tabaci populations in Mediterranean countries. This study aimed to evaluate the interactions among E. lutea, B. tabaci, and the host plant, obtaining comprehensive data to enhance its application in biological control programmes. Therefore, laboratory studies were carried out to determine the host-feeding capacity and parasitism of E. lutea at six B. tabaci nymph densities (10, 20, 40, 60, 80, and 100) on three host plant species: bean, cotton, and eggplant. The number of nymphs killed by the parasitoid through feeding and parasitism increased with increasing nymph densities for all host plants. The lowest (4.06) and the highest (27.5) mean numbers of parasitised nymphs were observed at host densities of 10 and 100 nymphs, respectively. The feeding behaviour of E. lutea was affected by the host plant, and the mean number of nymphs killed by feeding was found to be statistically significant and higher in cotton (6.7) than in bean (4.6) and eggplant (4.3), when pooled over all nymph densities. In conclusion, although the results showed that E. lutea can act as a density-dependent parasitoid, and its performance varies depending on the host plant, further studies on its hyperparasitism behaviour should be conducted before evaluating it as a potential candidate for the biological control agent of B. tabaci. [ABSTRACT FROM AUTHOR]

Effective management of tomato pests such as Bemisia tabaci and Tuta absoluta requires the integration of more sustainable control methods. Applying integrated pest management (IPM) approaches using combinations of biocontrol agents with agronomic practices such as the modulation of fertilisation offers opportunities toward more efficient pest control, all the more so since the underlying bottom-up and top-down regulations are interdependent. We investigated the relative influence of the bottom-up effects of reduced fertilisation (by 47%) and the use of the mirid predators Dyciphus errans or Macrolophus pygmaeus in combination with Nesidiocoris tenuis on the control of B. tabaci and T. absoluta. Densities of B. tabaci and T. absoluta population decreased more rapidly when fertilisation was reduced. The presence of D. errans caused reduction in N. tenuis densities and in the number of necrotic rings caused by N. tenuis. The negative effects of bottom-up forces triggered by reduced fertilisation on B. tabaci, T. absoluta and N. tenuis populations and damage were greater in the presence of D. errans. Our study shows that interactions between predators and fertilisation management are important in agro-ecosystems and should be considered in the development of sustainable IPM strategies. [ABSTRACT FROM AUTHOR]

Alternative control techniques are increasingly preferred in the management of vegetable pests because of the detrimental effects of pesticides on the environment and human health. Two popular environmentally friendly control strategies include natural enemy release and intercropping. In this study, the impact of intercropping aromatic plants (sweet pepper, sweet fennel, and marjoram) with three cucumber varieties (Hule, Muluki, and Basha) on the population density of Whitefly and Bemisia tabaci compared with non-intercropped plants was indicated during two consecutive seasons (2021 and 2022) under greenhouse conditions. The results showed that planting marjoram significantly reduced the population density of B. tabaci, followed by sweet pepper and sweet fennel. Our findings demonstrate the possibility of optimizing sustainable pest management through the integration of alternative pest control technologies. [ABSTRACT FROM AUTHOR]

Landscape fragmentation caused by agricultural expansion directly influences the spatial distribution of habitats and resources, favoring populations of pest insects such as the polyphagous whitefly Bemisia tabaci. Therefore, pest insects may constantly be dispersing between large- and small-scale crops that vary in quality and size at the landscape level. We aimed to understand how habitat use, dispersal movement and population dynamics of B. tabaci occur between large-scale and small-scale crops. We conducted a field experiment in large-scale soybean farms and small-scale farms cropping tomato plants in Brazil for two years. We collected soybean and tomato plant samples and adult whiteflies on these plants at different times of the phenological cycle of the crops. We determined the carbon and nitrogen stable isotope ratios of the plants and the whiteflies collected on these plants. We also estimated the population densities of whiteflies over time on these crops. We found that whitefly populations behave as metapopulations connected by dispersal. The isotopic ratios of B. tabaci revealed that large-scale soybean crops are source habitats of whitefly populations that, after harvest, disperse and redistribute among small-scale tomato farms causing a cascading effect on population growth on the latter. Therefore, understanding the spatial dynamics and management of pests such as whiteflies requires regional strategies, including large-scale and adjacent small-scale crops. C and N stable isotopes used here were able to track pest populations at the landscape level and, therefore, could be helpful to subsidize area-wide pest management strategies of whiteflies. [ABSTRACT FROM AUTHOR]

Bemisia tabaci MEAM1, the sweetpotato or silverleaf whitefly, transmits tomato yellow leaf curl virus, which significantly impacts production of tomato in Florida. This publication provides information on managing Bemisia tabaci and tomato yellow leaf curl virus to growers, UF/IFAS Extension agents, and other crop protection professionals. The publication describes and explains management strategies including the prompt destruction of harvested fields, the use of metalized plastic mulches and tolerant tomato varieties, and treatment of crops with insecticides and biopesticides for the control of Bemisia tabaci.

Abstract This research aimed to predict the seasonal incidence of whitefly, B. tabaci (Asia II 5) with its management by new plant systemic insecticides and their influence on natural enemies on potato crop. Results concluded that the whitefly population was slightly higher in 2020-21 than in 2019-20 and temperature (minimum and maximum), relative humidity (minimum), evaporation, and sunshine hours were key factors in determining the B. tabaci population buildup with reasonable accuracy (R2=0.82). Sequential spray of Diafenthiuron and Thiamethoxam (1.61 adults/3 compound leaves) was noticed to be the most effective treatment with the highest cost-benefit ratio (1:2.55), whereas two sequential sprays of Pymetrozine (3.17 adults/3 compound leaves) was found to be the least effective with the lowest cost-benefit ratio (1:1.61). All of the insecticides sequential spray examined were found to be either harmless or slightly detrimental to natural enemies (spiders and coccinellids). The current study concluded that B. tabaci population growth and seasonal incidence were greatly influenced by weather factors and this information validates the monitoring for early decision-making prior to developing insect pest management strategies against B. tabaci. Sequential spray of Imidacloprid and Thiamethoxam were shown reliable both from bio-efficacy and economic point of view in managing B. tabaci infestations in potato crop and can be incorporated into the IPM module.