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The recent discovery of the horizontal transfer of a toxin-neutralizing gene from plant to whitefly (Bemisia tabaci), a polyphagous insect, sparked a new area of study. In this forum, we discuss some potential biotechnological applications of this newly discovered knowledge in the coevolutionary arms race between plants and whitefly. [ABSTRACT FROM AUTHOR]

Tma12 is a fern-derived biopesticide (22 kDa) whose LPMO activity is associated with its insecticidal activity. The absence of the last 9 amino acids in the crystal structure of Tma12 suggested a possibility of its C-terminus processing. In this communication, we have shown the importance of protein C-terminus in the insecticidal activity. Additionally, we have also established the role of N-linked glycosylation in protein stability. Pichia produced (His) 6 tagged Tma12 in two forms. The 30 kDa protein comprising 192 amino acid residues did not show insecticidal activity. Contrary, 24 kDa protein exhibited toxicity to whiteflies with an LC 50 1.38 μg/ml. Absence of (His) 6 tag in 24 kDa protein indicated processing at the C-terminus which was confirmed with deletion mutagenesis. Failure in expressing glycosylation defective mutant suggested the importance of glycans in the stability of Tma12. New findings together with earlier reports suggest that along with the N-terminal catalytic center, correct C-terminus is pivotal for anti-whitefly activity of Tma12. [Display omitted] • Expression and purification of the first plant-based AA10 LPMO in P. pastoris. • C-terminus processing of Tma12 is critical for its anti-whitefly activity. • N-linked glycan is essential for protein stability. [ABSTRACT FROM AUTHOR]

Cotton Leaf Curl Virus (CLCuV) is a significant threat to cotton production, as it causes Cotton Leaf Curl Disease (CLCuD). Whitefly serves as a vector for the transmission of this virus. It can be controlled by developing barriers against whitefly infestation. The leaf epicuticle wax acts as a protective barrier against whitefly attacks. Research into wax biosynthesis and the fatty acid elongation pathway has highlighted the role of the 3-ketoacyl-CoA synthase (KCS) gene family in producing very-long-chain fatty acids (VLCFAs) in plants. The 3-ketoacyl-CoA synthase 6 (GaKCS6) gene, isolated from the CLCuV-resistant FDH-170 variety of Gossypium arboreum , was cloned under the control of the Ca MV35S constitutive promoter and transformed into the CLCuV-susceptible Gossypium hirsutum variety CKC-3 resulting in significantly higher leaf epicuticle wax deposition. Overexpression of GaKCS6 in the transgenic cotton plants was confirmed through quantitative real-time PCR. The transgenic plants not only exhibited average growth but also showed improvements in agronomic traits. Scanning Electron Microscope (SEM) analysis further validated the enhanced leaf epicuticle wax deposition in transgenic plants compared to non-transgenic (control). A free-choice bioassay against whiteflies demonstrated that the transgenic plants remained free of viral infection, as confirmed by real-time PCR. These findings indicate that increased leaf epicuticle wax deposition in transgenic cotton effectively prevents whitefly attacks and the transmission of CLCuV. It suggests that the GaKCS6 gene plays a crucial role in producing leaf epicuticle wax through the VLCFAs biosynthesis pathway. • Leaf epicuticle wax layer acts as a barrier against whiteflies in cotton plant. • Cotton Leaf Curl Virus (CLCuV) can be controlled by reduced whitefly attack on cotton crop. • Overexpression of 3-ketoacyl-CoA synthase 6 (KCS6) gene in cotton plants showed the role in wax biosynthesis pathway. • Gossypium arboreum (GaKCS6) CLCuV resistant gene improved leaf epicuticle wax in CLCuV susceptible Gossypium hirsutum. • GaKCS6 gene has no effect on fiber quality traits of transgenic cotton plants. [ABSTRACT FROM AUTHOR]

Specificity and efficiency of plant virus transmission depend largely on protein-protein interactions of vectors and viruses. Cucurbit chlorotic yellows virus (CCYV), transmitted specifically by tobacco whitefly, Bemisia tabaci , in a semi-persistent manner, has caused serious damage on cucurbit and vegetable crops around the world. However, the molecular mechanism of interaction during CCYV retention and transmission are still lacking. CCYV was proven to bind particularly to the whitefly foregut, and here, we confirmed that the minor coat protein (CPm) of CCYV is participated in the interaction with the vector. In order to identify proteins of B. tabaci that interact directly with CPm of CCYV, the immunoprecipitation (IP) assay and DUALmembrane cDNA library screening technology were applied. The cytochrome c oxidase subunit 5A (COX), tubulin beta chain (TUB) and keratin, type I cytoskeletal 9-like (KRT) of B. tabaci shown strong interactions with CPm and are closely associated with the retention within the vector and transmission of CCYV. These findings on whitefly protein-CCYV CPm interactions are crucial for a much better understanding the mechanism of semi-persistent plant virus transmission by insect vectors, as well as for implement new strategies for effective management of plant viruses and their vector insects. • The minor coat protein (CPm) of CCYV is a binding protein with vector Bemisia tabaci. • Six proteins in the foregut of B. tabaci (COX, TUB, KRT, ZFP, BTF and BTB) can directly interact with CPm. • RNAi-mediated knockdown of COX , TUB and KRT inhibits transmission of CCYV. [ABSTRACT FROM AUTHOR]

• Two resistant genotypes (IHR 4300 and IHR 4338) have been identified. • Cuticle thickness significantly negative correlated with adult survival, oviposition and nymphal population of whiteflies. • Higher concentration of phenolics and flavonoids are metabolic candidates for indirect selection of resistant genotypes. Whitefly is most devastating insect pest which causes damage by direct feeding on the host plant and also act as vector for transmission of many plant viruses causing severe yield losses in chilli. Host plant resistance is best advocated strategy in controlling the damage. We have screened the selected genotypes for white fly resistance using more accurate no-choice screening assays. Three types of assays i.e. clip-on-cage, detached branch and detached leaf methods of screening have been followed. Two resistant genotypes (IIHR 4300 and IIHR 4338) have been identified based on highest adult mortality, low oviposition rate, higher egg mortality and nymphal death. Cuticle thickness found significantly negative correlated with adult survival, oviposition and nymphal population. Semio-chemicals differing significantly amongst resistant and susceptible genotypes were identified through GC–MS and LC-MS and these can be used as metabolic candidates for indirect selection in screening genotypes/ populations for resistance. These two resistant chilli genotypes viz., IIHR 4300 and IIHR 4338 can be explored for breeding for white fly resistance. [ABSTRACT FROM AUTHOR]

Promoting arthropod biodiversity to increase ecosystem services through ecological intensification is a challenge for agriculture. And recent evidence suggests that standard pesticide applications not only harm natural enemies but may also fail to deliver long-term pest control solutions. To fuel ecological intensification and build predictive frameworks for pest management incorporating estimates of pest abundance, natural enemy abundance and their associated interactions is essential. Within this framework, there is a need to shift the focus from a single pest and predator to consider the community of predatory arthropods that interact with communities of prey. We took a network-based approach to investigate community interactions of predatory arthropods that feed on key pests and alternative prey in cotton over a three-year period. We merged prey activity, generalist predator communities collected from cotton canopies, and reconstructed trophic interactions with DNA detection frequencies estimated from molecular gut content analysis. Overall, many predator diets overlap, resulting in similar foraging patterns on groups of cotton pests. Moreover, predation on key cotton pests, such as stink bugs and white flies, was low. Therefore, ecological intensification that increases specialized arthropod predators within the community should improve biological control service delivery. • Predatory arthropod communities and associated prey communities are dynamic over a season and between years. • Crop stages contain dissimilar predatory communities for biological services. • Gut analysis and network estimates of predators shows overlap in biological services. • Aphids appear to provide food for many predator species. • Whiteflies and stink bugs in cotton represent weaknesses in natural pest regulation. [ABSTRACT FROM AUTHOR]

Pealius kufriensis Dubey sp. nov. is described from a native and invasive plant, Rubus ellipticus Sm. (Rosaceae) from the Western Himalaya, India. Puparial characteristics of the genus Pealius Quaintance and Baker are discussed. The new species and its associated plant are considered of quarantine importance. Pealius kufriensis Dubey sp. nov. , puparium on Rubus ellipticus Sm. [Display omitted] • Pealius kufriensis Dubey sp. nov. infesting Rubus ellipticus Sm. is described. • Puparial characteristics of the genus Pealius Quaintance and Baker are discussed. • The new species is of quarantine importance along with its associated plant species. Puparia of Pealius kufriensis Dubey sp. nov. found infesting a native and highly invasive plant, Rubus ellipticus Sm. (Rosaceae) are described. The host shrub was found highly infested with the new whitefly on the underside of leaves. Puparial characteristics of the genus Pealius Quaintance and Baker shared with Aleyrodes Latreille and Bemisia Quaintance and Baker are discussed. [ABSTRACT FROM AUTHOR]

• Coinfection of cassava with Cassava brown streak disease virus and its Ugandan variant is a threat to cassava production. • Coinfection is highly sensitive to roguing frequency and vector mortality. • Temperature variability causes multiple seasonal whitefly generations resulting in multiple epidemics. • Management of nymph development is more important than whitefly fecundity rate for epidemics' control. Mixed infections of Cassava brown streak virus (CBSV) and its Ugandan variant (UCBSV) in cassava hosts are increasingly threatening food security in East and Central Africa. The possibility of these viruses spreading to cassava producing countries in West Africa is of great concern. Most epidemiological models developed to address this challenge do not include the possibility of coinfection and whitefly lifecycle in managing these viruses. The question is: how does the inclusion of whitefly lifecycle and temperature variability influence disease outbreak and spread? We develop a host-vector-virus coinfection model that incorporates the whitefly life cycle and temperature variability as drivers of an epidemic. Using a combination of analytical and numerical simulations, we identify the key factors that drive disease outbreaks in cassava plantations. We also demonstrate that management of the whitefly's immature development stage can reduce disease prevalence and crop losses associated with these outbreaks. These results suggest that biological control agents using natural enemies should be given higher priority than the use of insecticides in management strategies. [ABSTRACT FROM AUTHOR]

One of the most destructive invasive pests worldwide is the whitefly, Bemisia tabaci MEAM1. The Florida vegetable crop market, worth millions of dollars annually, suffers major losses because of whitefly injury. Spirotetramat is frequently used by Florida vegetable crop growers to control whitefly nymphs. A previous study based on maximum dose bioassays indicated that MEAM1 populations in Florida may be developing resistance to spirotetramat. Thus, the long-term efficacy of this active ingredient depends on the development of baseline susceptibility data and the continued monitoring of MEAM1 populations' susceptibility. In the present study, 16 populations of whiteflies collected in south Florida were tested for resistance to spirotetramat through serial dilution bioassays designed to test whitefly nymphs. The field populations' responses were compared with a susceptible MEAM1 laboratory colony. Median lethal concentrations (LC 50) and resistance ratios (RRs) were quantified to determine MEAM1 resistance levels. Among the populations tested, 12.5% remained relatively susceptible (3–4 RR) to spirotetramat. Low to moderate resistance was found in 56% of the populations (16–58 RR). Over 30% of the populations tested were highly or extremely resistant (126–795 RR). Overall, the variable susceptibility of spirotetramat in some field populations indicates that resistance to this insecticide has developed in certain regions of south Florida. This is the first report of spirotetramat resistance in the United States. These results will directly refine management recommendations for spirotetramat use in areas where MEAM1 populations exhibit resistance. • This study represents the first report of B. tabaci resistance to spirotetramat in the United States. • 12.5% of the populations were susceptible to spirotetramat, and the remaining populations had low to extreme resistance. • Resistance patterns may be influenced by local agricultural practices, with variations in different counties and crops. • Results underscore the need for region-specific IPM strategies to combat escalating resistance to spirotetramat. [ABSTRACT FROM AUTHOR]

Whitefly and the viruses they transmit pose a serious threat to crops globally. Recently, Jain et al. showed that BioClay-mediated double-stranded RNA (dsRNA) spray provides an eco-friendly approach to controlling whitefly. This 'transgene-free next-generation' insect-specific crop protection strategy may help to reduce the use of chemical pesticides for controlling whitefly. [ABSTRACT FROM AUTHOR]

• Whitefly is a hazardous insect pest that causes significant damage to crops worldwide. • The study focused on three genes (BG, NPR1, and PAL) in cotton to understand their role in whitefly stress response. • Insilico analysis revealed the functional domains and phylogeny of these genes in different cotton species. • Gene down-regulation through VIGS resulted in reduced whitefly egg and nymph production, indicating the importance of these genes in whitefly resilience. Whitefly is one of the most hazardous insect pests that infests a wide range of host plants and causes huge damage to crop worldwide. In order to engineer plants resilient to whitefly stress, it is important to identify and validate the responsive genes by exploring the molecular dynamics of plants under stress conditions. In this study three genes BG, NPR1, and PAL genes have been studied in cotton for elucidating their role in whitefly stress response. Initially, insilico approach was utilized to investigate the domains and phylogeny of BG, NPR1 and PAL genes and found out that these genes showed remarkable resemblance in four cotton species Gossypium hirsutum, G. barbadense, G. arboreum, and G. raimondii. In BG proteins the main functional domain was X8 belonging to glycohydro superfamily, in NPR1 two main functional domains were BTB_POZ at N terminal and NPR1_like_C at C terminal. In PAL functional domain PLN was found which belongs to Lyase class I superfamily. The promoter analysis of these genes displayed enrichment of hormone, stress and stimuli responsive cis elements. Through Virus Induced Gene Silencing (VIGS), these genes were targeted and kept under whitefly infestation. Overall, the whitefly egg and nymph production were observed 60–70% less on gene down regulated plants as compared to control plants. The qPCR-based expression analysis of certain stress-responsive genes showed that in BG down regulated plants the elevated expression of these whitefly responsive genes was detected, in NPR1 down regulated plants JAZ1 and HSP were found up regulated, ERF1 and WRKY40 didn't show significant differential expression, while MAPK6 was slightly down regulated. In PAL down regulated plants ERF1 and JAZ1 showed elevated expression while others didn't show significant alternation. Differential expression in gene down-regulated plants showed that whitefly responsive genes act in a complex inter signaling pathway and their expression impact each other. This study provides valuable insight into the structural and functional analysis of important whitefly responsive genes BG, NPR1, and PAL. The results will pave a path to future development of whitefly resilient crops. [ABSTRACT FROM AUTHOR]

The whitefy Bemisia tabaci , a species complex consisting of many morphologically indistinguishable species divided into distinct clades, is one of the most globally important agricultural pests and plant virus vectors. Cassava-colonizing B. tabaci transmits viruses that cause cassava mosaic disease (CMD) and cassava brown streak disease (CBSD). Half of all cassava plants in Africa are affected by these viral diseases, resulting in annual production losses of more than US$ 1 billion. Here we report the draft genome of the cassava whitefly B. tabaci Sub-Saharan Africa - East and Central Africa (SSA-ECA), the super-abundant population that has been associated with the rapid spread of viruses causing the pandemics of CMD and CBSD. The SSA-ECA genome assembled from Illumina short reads has a total size of 513.7 Mb and a scaffold N50 length of 497 kb, and contains 15,084 predicted protein-coding genes. Phylogenetic analysis suggests that SSA-ECA diverged from MEAM1 around 5.26 million years ago. A comprehensive genetic analysis of cassava-colonizing B. tabaci in Africa was also conducted, in which a total of 243 whitefly specimens were collected from 18 countries representing all major cassava-growing regions in the continent and genotyped using NextRAD sequencing. Population genomic analyses confirmed the existence of six major populations linked by gene flow and inferred the distribution patterns of these populations across the African continent. The genome of SSA-ECA and the genetic findings provide valuable resources and guidance to facilitate whitefly research and the development of strategies to control cassava viral diseases spread by whiteflies. Image 1 • A draft genome of the African cassava whitefly Bemisia tabaci was generated, which contained 15,084 protein-coding genes. • Comparative genomic analyses were performed to infer divergence time between different whitefly species. • A total of 243 whitefly specimens were collected from all major cassava-growing regions in Africa and genotyped. • Genetic diversity and distribution patterns of cassava-colonizing whiteflies in Africa were analyzed. [ABSTRACT FROM AUTHOR]

The Economic Injury Level (EIL) for pest insects is conventionally expressed in terms of the number of insects, because the level of pest injury to plants is usually difficult to quantify. However, when insect injury is mainly caused indirectly by transmission of plant pathogens, the number of insects may not be an ideal measure to calculate the EIL. The greenhouse whitefly (GWF) Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae) is the only known vector of the Potato yellow vein virus (PYVV), the causal agent of potato yellow vein disease (PYVD), but the direct injury caused by insect feeding may not be significant since potato is not a preferred host for the GWF. Here, we quantified the effect of GWF feeding and PYVD incidence on potato yield, as compared to potato market value and control costs to determine the EIL for this system. We found that the direct injury caused by GWF feeding does not affect potato yield. However, an exponential reduction in crop yield was observed with the increase of PYVD incidence. Thus, the criteria to decide upon applying a control measure ranges between 100 and 1200 infected plants/ha depending mainly on potato market price. We suggest that disease incidence should be used to calculate the EIL for PYVD management, instead of focusing on estimations of vector population size. Furthermore, we stress that potato market price is fundamental in defining an appropriate, case specific EIL for decision-making in PYVD management. Image 1 • We developed a decision-making criterion for PYVD management. • GWF feeding has a negligible effect on potato yield. • Potato yield decreases exponentially with PYVD incidence. • PYVD incidence is key to decide upon interventions to control disease spreading. • Good predictions of produce price are key to define decision-making thresholds. [ABSTRACT FROM AUTHOR]

Horizontal gene transfer (HGT) is a well-documented evolutionary driving phenomenon in prokaryotes and eukaryotes, but its impact on the plant kingdom has remained elusive. A recent study provides compelling evidences, which support the idea that a plant-derived gene allows for the detoxification of plant defense metabolites in a polyphagous arthropod herbivore. [ABSTRACT FROM AUTHOR]

Within the Bemisia tabaci group of cryptic whitefly species, many are damaging agricultural pests and plant-virus vectors, conferring upon this group the status of one of the world's top 100 most invasive and destructive species, affecting farmers' income and threatening their livelihoods. Studies on the microbiome of whitefly life stages are scarce, although their composition and diversity greatly influence whitefly fitness and development. We used high-throughput sequencing to understand microbiome diversity in different developmental stages of the B. tabaci sub-Saharan Africa 1 (SSA1-SG1) species of the whitefly from Uganda. Endosymbionts (Portiera , Arsenophonus , Wolbachia, and Hemipteriphilus were detected but excluded from further statistical analysis as they were not influenced by life stage using Permutational Multivariate Analysis of Variance Using Distance Matrices (ADONIS, p = 0.925 and Bray, p = 0.903). Our results showed significant differences in the meta microbiome composition in different life stages of SSA1-SG1. The diversity was significantly higher in eggs (Shannon, p = 0.024; Simpson, p = 0.047) than that in nymphs and pupae, while the number of microbial species observed by the amplicon sequence variant (ASV) was not significant (n(ASV), p = 0.094). At the phylum and genus levels, the dominant constituents in the microbiome changed significantly during various developmental stages, with Halomonas being present in eggs, whereas Bacillus and Caldalkalibacillus were consistently found across all life stages. These findings provide the first description of differing meta microbiome diversity in the life stage of whiteflies, suggesting their putative role in whitefly development. [ABSTRACT FROM AUTHOR]

Glycine max (L) soybean (Merr) is the world's most widely produced and consumed oilseed. Since its establishment in Brazilian fields, the sweetpotato whitefly Bemisia tabaci (Gennadius 1899) Hemiptera: Aleyrodidae became a notorious pest in soybean fields. However, there is not a sampling plan specifically designed to scout B. tabaci adults in tropical soybean crops. Hence, this study aimed to develop a standardized sampling plan for scouting B. tabaci adults in tropical agriculture. This study was conducted in commercial soybean fields in the Brazilian Savanah from 2017 to 2021, encompassing the vegetative, flowering, and fruiting stages. B. tabaci adults were evaluated to establish a conventional sampling plan, following a five-step approach: (i) determination of the appropriate sample unit, (ii) sampling technique evaluation, (iii) analysis of the frequency distribution of B. tabaci were evaluated to establish a conventional sampling plan, following a five-step approach density, (iv) calculation of the optimal number of samples, and (v) assessment of costs and sampling time. The apical part of the soybean canopy was the ideal sampling unit for assessing B. tabaci populations throughout the plant cycle. Beating the apical part of the plant against a plastic tray proved to be the most suitable sampling technique. A total of 49 samples per field were required to effectively scout this pest. The sample process lasted no more than 5 min per hectare, and the associated costs did not exceed US$ 0.74 per hectare. These results provide the first precise and representative standardized sampling plan to scout B. tabaci adults in tropical soybean fields. [Display omitted] • The first standardized sampling plan to scout B. tabaci adults in soybean fields. • The ideal sampling unit to scout whitefly is the apical part of the soybean plant. • Whitefly sampling technique was beating the soybean plant against a plastic tray. • The number of soybean plants demanded to scout whitely was 49 samples per field. [ABSTRACT FROM AUTHOR]

Integrated Pest Management (IPM) is an essential approach used in smart agriculture to manage pest populations and sustainably optimize crop production. One of the cornerstones underlying IPM solutions is pest monitoring, a practice often performed by farm owners by using chromotropic sticky traps placed on insect hot spots to gauge pest population densities. In this paper, we propose a modular model-agnostic deep learning-based counting pipeline for estimating the number of insects present in pictures of chromotropic sticky traps, thus reducing the need for manual trap inspections and minimizing human effort. Additionally, our solution generates a set of raw positions of the counted insects and confidence scores expressing their reliability, allowing practitioners to filter out unreliable predictions. We train and assess our technique by exploiting PST - Pest Sticky Traps, a new collection of dot-annotated images we created on purpose and we publicly release, suitable for counting whiteflies. Experimental evaluation shows that our proposed counting strategy can be a valuable Artificial Intelligence-based tool to help farm owners to control pest outbreaks and prevent crop damages effectively. Specifically, our solution achieves an average counting error of approximately 9 % compared to human capabilities requiring a matter of seconds, a large improvement respecting the time-intensive process of manual human inspections, which often take hours or even days. • Pest monitoring is an essential pillar of IPM strategies requiring great human effort. • Deep learning pipeline for counting insects on chromotropic sticky trap pictures. • Novel dot-labeled dataset for counting whiteflies on sticky trap images. • In-depth assessment of counting and localization performance of several approaches. • Counting error of 9% compared to human capabilities through a few-seconds processing. [ABSTRACT FROM AUTHOR]

Highlights • High-throughput sequencing of RNA from whiteflies reveals a new ss(+)RNA virus. • This is the first dicistrovirus identified in Bemisia tabaci. • This virus is detected in both adults and nymphs. • The name Bemisia-associated dicistrovirus 1 (BaDV-1) is proposed. Abstract A novel single-stranded RNA virus was detected in a whitefly (Bemisia tabaci) sample subjected to high-throughput sequencing. The 8293 nt-long genome presents a polyadenylated 3' end, and contains two ORFs encoding putative 1596 and 849 aa-long proteins. These putative proteins display significant similarity to replicase and capsid polyproteins, respectively, of discitroviruses. Its complete genome sequence shared the highest nucleotide identity (59.8%) with cricket paralysis virus (family Dicistroviridae , genus Cripavirus). Phylogenetic analyses showed that this new virus putative protein sequences clustered with those from members of Dicistroviridae. However, the replicase and capsid polyprotein sequences clustered with those of members of different genera, respectively to Aparavirus and Cripavirus. RT-PCR using newly collected adult and nymph whitefly samples confirmed the presence of this virus in field populations of B. tabaci. Genome sequence and organization, and polyproteins comparison indicate that this virus is a new species of the family Dicistroviridae. The name Bemisia-associated dicistrovirus 1 is proposed for this virus. [ABSTRACT FROM AUTHOR]

Papaya virus Q (PpVQ) is an umbra-like virus found in papaya plantings of Ecuador. A most recent study conducted in Brazil has reported the presence of a virus with 70% nucleotide identity to PpVQ. The Brazilian virus was shown to act synergistically with Papaya meleira virus (PMeV) to induce a devastating disorder known as papaya meleira. This finding prompted us to investigate epidemiology aspects of PpVQ, especially its transmission and potential involvement with meleira like symptoms in Ecuador. Three out of ten plants inoculated with ‘viruliferous’ whiteflies ( Bemisia tabaci ) tested positive for PpVQ; whereas no mechanical or seed transmission was observed. Surveys using a multiplex RT-PCR assay for the simultaneous detection of PpVQ, PMeV and Papaya ringspot virus (PRSV) revealed that PpVQ is found most commonly in co-infections with PRSV, but also in single infections in asymptomatic plants. PMeV, on the other hand, was not detected in any of the tested plants. Interestingly, two virus sequences with homology to PpVQ and PMeV, respectively, were found in leaf samples from babaco ( Vasconcellea x heilbornii, syn. Carica pentagona ), a sub-tropical relative of papaya native to Ecuador, highlighting the importance of implementing a surveillance scheme for papaya meleira disease in Ecuador as a preventative management and control strategy. [ABSTRACT FROM AUTHOR]

Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) cryptic species complex represents a major threat to several important crops including vegetables, cereals, fruits, and ornamentals worldwide. One important mode of its dispersal is through the trans-boundary (domestic, international) movement of infested plant materials. To prevent the spread of this invasive insect pest on inter-state ornamental shipments, the efficacy of biopesticides was tested through dip treatments of plant material pre-shipping. In several experiments, clean Mentha sp. (Lamiaceae), mint plants were exposed to adults of B. tabaci for 1 or 6 days. Adults were removed from plants and eggs, and immature stages were treated with one or a combination of the following: entomopathogenic fungi Beauveria bassiana (BotaniGard ® ), Isaria fumosorosea (Preferal ® ), the surfactant Natur'l Oil™, and soap (Publix ® ). After treatment application, plants were placed in commercial cardboard boxes and shipped from Apopka, Florida (FL) to Fort Pierce, FL. Assessments for the treatment efficacies were conducted at 3, 7, and 14 days post arrival of the shipment. Fungal entomopathogens; B. bassiana, I. fumosorosea , and the surfactant Natur'l Oil™, showed significant reduction in the whitefly population compared to the untreated control ( P  < 0.05). Significantly higher corrected mortality of the whitefly populations was observed when B. bassiana was applied alone (81%) or in combination with Natur'l Oil™ (86%), as well as I. fumosorosea applied in combination with Natur'l Oil™ (77%). Our results showed that pre-shipping dip treatment applications of either Natur'l Oil™ mixed with B. bassiana or I. fumosorosea or B. bassiana applied alone could help mitigate the inter-state spread of whitefly on ornamental shipments. [ABSTRACT FROM AUTHOR]

Whiteflies are important insect pests in a wide variety of agricultural crops that are targeted with large quantities of insecticides on a global scale. Chemical control is the most common strategy to manage whiteflies, however, recent studies had reported that whiteflies and other hemipterans can excrete insecticides through their honeydew, which could have unanticipated, non-target effects. The objective of this study was to determine the concentration of imidacloprid in honeydew excreted by whiteflies feeding on tomato plants. Imidacloprid was applied at its labeled rate to soil at the base of whitefly-infested plants. Densities of whiteflies were assessed before insecticide treatment and 21 days after treatment (DAT). Honeydew was collected in Petri dishes from 1 to 4 DAT and from 5 to 8 DAT. The volume of the honeydew was calculated using stereo microscopy and then rinsed with ethanol. The rinsates were analyzed to determine imidacloprid concentration using liquid chromatography coupled to mass spectrometry. Honeydew production was further quantified by using water sensitive papers. Imidacloprid reduced densities of nymph and adult whiteflies by 81.5% and 76.0% compared to the control at 21DAT. The non-metabolized parent compound imidacloprid was detected from honeydew samples at both collection dates. At 1–4 DAT, imidacloprid concentrations were 180 ng/30 mL in a volume of 39 mm3 of honeydew. At 5–8 DAT, the imidacloprid concentration was 218 ng/30 mL in a volume of 25 mm3 of honeydew. Though the volume of honeydew decreased, the concentration of imidacloprid numerically increased. Last, whiteflies were still producing honeydew 22 DAT in both treatments. These results revealing significant imidacloprid concentrations in honeydew suggest a strong potential for negative secondary impacts on beneficial insects. The insecticide imidacloprid was detected in honeydew excreted by whitefly adults and nymphs after feeding on tomato leaves on plants that received via soil applications of imidacloprid. Honeydew was collected in Petri dishes through time after treatment for quantitation and chemical analysis. Honeydew production extended to 22 days after treatment (DAT) with increasing imidacloprid concentrations occurring in the honeydew over time. [Display omitted] • Whiteflies excreted non-metabolized imidacloprid through honeydew in tomato plants • Imidacloprid concentrations increased despite reductions in honeydew amount over time • Whiteflies produced honeydew in imidacloprid treatments to 22 DAT • Imidacloprid in honeydew likely has an impact on beneficial insects [ABSTRACT FROM AUTHOR]

Flower strips are advocated as a strategy to promote beneficial insects as well as the services they deliver to adjacent crops. Flower strips have, however, often been developed separately for pollinators and natural enemies and, additionally, little consideration has been given to effects on insect herbivores. We sampled insect herbivores, their natural enemies and parasitism of pest eggs using vacuum sampling, sticky cards and egg cards in nine pairs of bee-attractive wildflower plantings and control field borders, as well as in adjacent tomato and watermelon crop fields in Yolo County, California 2015–2016. Control field borders had a higher total number of herbivores on sticky traps than did wildflower plantings, a pattern that was driven by more aphids, hoppers, psyllids and whiteflies, whereas wildflower plantings had more lace bugs and Lygus bugs. The total number of herbivores in the adjacent crop fields did not differ between treatments, but there were more leaf beetles near (at 10 m but not 50 m from) wildflower plantings. Control field borders had a higher total number of predators, driven by more big-eyed bugs, lady beetles and minute pirate bugs, whereas spiders were more common in wildflower plantings. The total number of predators in adjacent crop fields was, however, higher in those next to wildflower plantings, which was driven by more minute pirate bugs. Parasitoid wasps were more common in wildflower plantings and at 10 m but not 50 m into adjacent crop fields. Stink bug egg parasitism rate did not differ between treatments, either in the borders or in the crop fields. In conclusion, wildflower plantings clearly affect the insect herbivore and natural enemy community, but do so in a highly taxon-specific manner, which can lead to both positive and negative outcomes for pest control as a result. • Effects of wildflower plantings on herbivores and natural enemies were taxon-specific. • •Wildflower plantings promoted natural enemies in adjacent crop fields. • No consistent effect on herbivores and egg parasitism in adjacent crop fields. [ABSTRACT FROM AUTHOR]

The betel vine (Piper betle L.) is one of the plantation crops commercially cultivated for its leaf in South and Southeast Asia. The leaf production is often threatened by different insect pests including Aleurocanthus rugosa Singh (Hemiptera: Aleyrodidae). Currently, infestations of A. rugosa in betel vine are primarily controlled using excessive conventional broad-spectrum chemical pesticides that pose serious human health risks due to the masticatory nature of consumption. This study was carried out to investigate the performance of colored sticky traps and biopesticides against A. rugosa as an ecofriendly approach by conducting multilocation field trials from 2019 to 2021. It was observed that the A. rugosa population prevailed throughout the year, however, insect infestation was higher in May and October due to the high temperature. Among the sticky traps, A. rugosa was highly attracted to the yellow-colored traps compared to white or blue traps. Whereas alternating sprays of either D-lemonine (Bio clean® 5% SL) or spinosad (Success® 2.5% SC) with sodium lauryl ether sulphate (Fizimite® 10%) reduced the A. rugosa population by 71.4–79.0% over control. Further, a combination of these spray regimes with yellow-colored sticky traps as IPM packages showed improved results in reducing pest populations by 83.8–86.0% and increasing leaf yield by 60.4–63.6% over control. Even the performance of the IPM packages was better than farmers' practice i.e., broad-spectrum chemical pesticides. Thus, the outcome of this study indicates that the IPM program could be a sustainable and environmentally friendly method of controlling A. rugosa in betel vine production. [Display omitted] • Aleurocanthus rugosa in betel vine appears throughout the year with peaks in May and October. • Yellow colored sticky trap is more effective to capture A. rugosa adult. • Alternate spraying of D-Lemonine or Spinosad with sodium lauryl ether sulphate are effective to control A. rugosa. • Yellow colored sticky traps with spraying of biopesticides are an effective IPM package against A. rugosa. [ABSTRACT FROM AUTHOR]

Pigments are important in vegetable kingdom. However, little is known regarding role of their combination in pepper. In this study, three pepper strains were crossed to get F1 pepper plants, and exposed to whitefly attack at 6–8 leaves stage. Populations (M1–M9) differing in leaf color divulged that leaf color inherited to progenies at different extent and intensively showed matrocliny. Furthermore, in purple-colored population, the accumulation of anthocyanin improved the physiology and resistance to whitefly, with increased photosynthetic rate (Pn), Fv/Fm as well as root activity and reduction in superoxide dismutase (SOD), peroxidase (POD), malonaldehyde (MDA) and pest index (PI). Best manifestation of these parameters was observed in M3 population, indicating plant development be related to the optimum combination of anthocyanin and chlorophyll in the investigated leaves. Interestingly, M3 population possessed highest resistance to whitefly, while level of its anthocyanin and chlorophyll was in moderate level. Besides, no significant difference was observed in the expression levels of genes related to carotenoid metabolism in all populations. significant correlation was observed between PI and expression of genes related to pigment, namely CaGLK and CaCHS genes (R2 > 0.8), while the correlation was also found between ANS and GUN 4 genes. These results suggested that the combination of anthocyanin and chlorophyll could enhance the resistance of pepper plants against whitefly attack. [ABSTRACT FROM AUTHOR]

[Display omitted] • Insects recurrently acquired RIP-encoding genes via horizontal gene transfer. • Insectś RIP genes showed temporal/spatial expression convergence. • Pathogen infection induces RIP expression in A. aegypti. • RIP depurinate pathogenś ribosomes suggesting that they retain their enzymatic activity. Ribosome-inactivating proteins (RIPs) are RNA N -glycosidases that depurinate an adenine residue in the conserved alpha-sarcin/ricin loop (SRL) of rRNA, inhibiting protein synthesis. Previously, we reported the existence of these toxins in insects, whose presence is restricted to mosquitoes from the Culicinae subfamily (e.g., Aedes aegypti) and whiteflies from the Aleyrodidae family (e.g., Bemisia tabaci). Both groups of genes are derived from two independent horizontal gene transfer (HGT) events and are evolving under purifying selection. Here, we report and characterize the occurrence of a third HGT event in the Sciaroidea superfamily, which supports the recurrent acquisition of RIP genes by insects. Transcriptomic experiments, available in databases, allowed us to describe the temporal and spatial expression profiles for these foreign genes in these organisms. Furthermore, we found that RIP expression is induced after infection with pathogens and provided, for the first time, transcriptomic evidence of parasite SRL depurination. This evidence suggests a possible role of these foreign genes as immune effectors in insects. [ABSTRACT FROM AUTHOR]

The sweetpotato whitefly Bemisia tabaci is a destructive pest on a wide variety of agricultural crops. Whiteflies are managed largely through the use of insecticides, but B. tabaci has developed tolerance or resistance to a broad range of active ingredients. Identifying events where insecticide applications could be delayed or eliminated may mitigate insecticide resistance. One such event is cold weather, which can decrease whitefly activity including dispersal and mating, or kill a substantial proportion of the whitefly population when temperatures fall below freezing. The objective of this research was to quantify the effects of exposure period to subfreezing temperatures on the mortality of adult whitefly. Results showed that whitefly mortality could be predicted through a non-linear function of a composite variable of temperature and exposure time (x). This model was applied retroactively to six seasons of field data collected in southwest Florida during the months of November through February. Based on observation and model output, significant drops in the whitefly population were mostly associated with two or more cold events – separated by no more than 7 days – with at least one of those events with x > 13. Moreover, the decrease was sustained for 4–6 weeks after the last event. The ability to predict decreases in the whitefly population in response to freeze events gives growers the opportunity to relax insecticide schedules, particularly in the spring cropping season, with high confidence that their crop is at low risk to whitefly damage. • Whitefly mortality is predictable during cold events. • Serial cold events increases whitefly mortality in agroecosystems. • Whitefly population recovery lags plant recovery. • The recovery lag affords producers an opportunity for relaxed management. [ABSTRACT FROM AUTHOR]

The whitefly Bemisia tabaci (Gennadius) is the vector of cassava mosaic viruses causing cassava viral diseases, which are the most important biotic constraints of cassava production in sub-Saharan Africa (SSA). Presently, B. tabaci management in cassava fields calls for the development of an integrated approach that relies on host plant resistance and biological control. Data on B. tabaci's natural enemies, particularly parasitoids, in Central Africa are limited. Field surveys were conducted from 2015 to 2017 to identify parasitoids associated with B. tabaci in 5 Cameroon agro-ecological zones. Additionally, population dynamics studies were conducted in replicated fields experiments were conducted from 2016 to 2018 to identify cassava genotypes that can best promote B. tabaci parasitism. Two parasitoids, Encarsia sophia (Girault & Dodd) and Encarsia lutea (Masi) were found parasitizing B. tabaci nymphs with higher parasitism by E. lutea compared with E. sophia. The average parasitism rate during the survey was 33.4% for E. lutea and 8.4% for E. Sophia, regardless of AEZ. The highest parasitism rates by E. lutea (48.2% and 24.2% from field trials and surveys, respectively) were observed in the Western Highlands (AEZ 3) while parasitism by E. sophia was less than 12.4%. Four cassava genotypes (I090590, I011797, I090574, and I070593) promoted higher parasitism rates of B. tabaci by E. lutea and E sophia. The contributions of the two parasitoids and their integration with cassava genotypes for the management of B. tabaci in cassava fields are discussed. • Three-years countrywide surveys of Bemisia tabaci in Cameroon. • Encarsia lutea and E. sophia identified from parasitized B. tabaci nymphs. • Higher parasitism rate obtained from E. lutea. • Two cassava genotypes (I090590, I011797, I090574, and I070593) recorded the highest parasitism rates. • Total parasitism reached 39.2% regardless of the Agro-ecological zones. [ABSTRACT FROM AUTHOR]

The Bemisia tabaci whitefly is an important pest of many agricultural crops. Direct feeding by this pest can cause physiological plant symptoms including irregular ripening in tomatoes and silverleaf disorder in squash. In addition, B . tabaci can transmit more than 100 plant viruses that cause severe diseases that affect crop yield and quality. Insecticides are often applied to control this pest and they may be applied to the foliage and/or to the soil. Insecticides that kill quickly or cause feeding cessation reduce the damage caused by B . tabaci on the host plant most effectively. In this study fluorescence was used to assess B . tabaci feeding and to determine the effect of systemically applied insecticides on feeding by the pest. Cyantraniliprole (Verimark™) and imidacloprid (AdmirePro ® ) produced a rapid reduction in B . tabaci feeding. At 24 h after a systemic application, the percentage of whitefly nymphs still feeding in plants treated with cyantraniliprole (anthranilic diamide) and imidacloprid (neonicotinoid) were 19% and 33%, respectively. Both products showed a good reduction in insect feeding and since they have different modes of action they should be considered as rotational partners for B . tabaci control in areas where there is no resistance to neonicotinoid insecticides. While the fluorescein sodium salt cannot be used to trace the uptake of insecticides, it has been shown to reliably demonstrate feeding cessation of whitefly nymphs after foliar and systemic applications of insecticides. [ABSTRACT FROM AUTHOR]

• Glandular trichomes are the directly related to resistance to whitefly and pinworm. • The number of tector trichomes did not led to resistance against the tested insects. • Solanum pennellii LA-716 is the most resistant to whitefly and tomato pinworm. Resistance genes to pests such as Bemisia tabaci and Tuta absoluta can be abundant in wild tomato genotypes. For breeding program initiatives, the characterization of the germplasm in terms of resistance to pests and related morphoanatomical characteristics is essential. Thus, the objective of this study was to evaluate the resistance of different accessions of species of Solanum sp., section Lycopersicon to B. tabaci and T. absoluta and establish a relationship with the types of trichomes present on the leaf surface. Whitefly oviposition, nymphs, and exuviae were investigated in 35 genotypes. On the leaf surface of the genotypes, glandular and non-glandular trichomes were identified and quantified. Based on the results, the genotypes were chosen for pinworm testing. Thirteen tomato genotypes were investigated, including Solanum lycopersicum var. cerasiforme , two accessions of S. lycopersicum , and ten wild accessions of Solanum sp., section Lycopersicon. At 7, 14, 21, and 28 days after infestation, eggs were counted on the abaxial surface of the leaflets, and the extent of damage caused by the tomato leafminer was determined using multivariate analysis and the area under the attack severity progress curve. Leaf trichomes of the 13 pre-selected genotypes were identified and quantified. The findings for the whitefly showed that wild genotypes were more resistant than the commercial ones due to the presence of trichomes, mainly glandular trichomes. According to principal component analysis, stronger materials in whitefly tests correlated more with the number of glandular trichomes. Finally, glandular trichomes positively correlate with the genotype's defense against pests. Solanum pennellii LA-716 and S. habrochaites var. hirsutum PI-127826 were the genotypes with the lowest number of oviposition and damage caused by the moth. This trait was also related to the higher density of glandular trichomes. The results show variability among accessions of the same species for trichome density and pest resistance. This information allows the choice of the best accessions among the species when defining the parents to be used in initial crosses of breeding programs. [ABSTRACT FROM AUTHOR]

• Long-read isoform sequencing reveals transcriptomic diversity of Desi cotton. • Alternative splicing and alternative polyadenylation are important players in determining superior defense of Desi cotton by activating different transcript isoforms under stresses. • Differential transcript isoforms could be one way of conferring biotic and abiotic resistance in cotton. Alternative splicing (AS) and alternative polyadenylation (APA) are common mechanisms in eukaryotes to increase the complexity of transcriptomes and subsequently proteomes. Analysis of long reads transcriptomics data can result in the discovery of novel transcripts, splice sites, AS or APA events. Gossypium arboreum is an important cultivated cotton species and a putative contributor of the A sub-genome to the modern tetraploid cotton; and inherently tolerant to several biotic and abiotic stresses. Specifically, its variety 'FDH228′ is considered to be an important resistance source. In this study, we sequenced the G. arboreum (var. FDH228) transcriptome using PacBio IsoSeq and illumina short read sequencing under three different conditions i.e. untreated/healthy, treated with biotic stress through whitefly infestation, and treated with abiotic stress via water deprivation, for the discovery and surveying of canonical and non-canonical AS, APA and transcript fusion events. We were able to obtain 15,419 unique transcripts from all samples representing 11,343 genes, out of which 10,832 were annotated and 520 were novel with respect to the published reference genome. These transcripts were grouped into different structural categories including 60 Antisense, 11,959 having a full-splice match, 999 with incomplete-splice match, 30 fusion transcripts, 177 genic, 479 intergenic, 771 novels in the catalog, and 944 Novel but not found in the catalog. Subsequently, randomly selected candidate transcripts were experimentally validated using qRT-PCR. Our comprehensive identification of canonical and non-canonical splicing events, and novel and fusion transcripts aids in the understanding of the resistance mechanisms for this specific germplasm. [ABSTRACT FROM AUTHOR]

Soybean is the main agricultural crop produced and exported by Brazil, and the whitefly, Bemisia tabaci (Gennadius, 1889) (Hemiptera: Aleyrodidae), is one of the main pests of this crop. Whitefly control is carried out mainly with chemical insecticides, which has led to an increase in number of applications and evolution towards resistant populations. There is a need to study alternatives for the control of this insect pest, and biological control using entomopathogenic fungi can be an effective tool, offering less risk to the environment. This study aimed to design and evaluate four management programs in two soybean cropping seasons, including two integrated management alternatives, a conventional chemical management alternative and a biological (fungal) control alternative. Two sequential sprays set 10 days apart were performed for each program, and the results of ANOVA and Scott-Knott test (P ≤ 0.05) revealed differences among treatments. The integrated management consisting of a sequential spray of chemical insecticide followed by a fungal one stood out as the best control option, presenting 60% of control efficacy for whitefly adults and 34% for whitefly nymphs in the first cropping season; 83% of control efficacy for whitefly adults and 53% for whitefly nymphs in the second cropping season. Therefore, integrating fungi-based products with chemical insecticides may provide an efficient alternative for controlling B. tabaci in soybean. • Integrating entomopathogenic fungi-based products with chemical insecticides enhances B. tabaci control in soybean. • Applying fungi-based products after two sprays of chemical insecticides provides 60–83% of control for whitefly adults. • This strategy is more effective for B. tabaci control than applying fungal products in the first spray or alone. [ABSTRACT FROM AUTHOR]

• Whitefly inflicts both direct and indirect losses to the cotton crop. • Tomato-associated Mi-1.2 gene has been successfully deployed in tomato cultivars to attain whitefly resistance. • In the present study, putative Mi-1.2-like orthologs were identified in five different whitefly hosts and functionally validated through virus-inducing gene silencing (VIGS) in cotton plants. • We have concluded that cotton-associated Mi-1.2-like orthologs showed a close relation with cassava and tomato genes. Moreover, Mi-like R genes could be the potential candidates for deriving whitefly resistance response in cotton plants. Whitefly (Bemisia tabaci) inflicts tremendous yield losses to cotton crops in many parts of the world by sap-sucking and transmitting viral diseases. The tomato-associated Mi-1.2 gene has been successfully deployed in tomato cultivars to attain whitefly resistance. In the current study, putative Mi-1.2-like orthologs were identified in five whitefly hosts and functionally validated through virus-inducing gene silencing (VIGS) in cotton plants. The expression profiling and qPCR results depicted differential regulation of the Mi-1.2-like gene in various tissue types and under different biotic and abiotic stresses, especially in whitefly susceptible and resistant cotton plants. The upregulation of the Mi-1.2-like gene (Gadrp RPP-13 Like gene) was observed at 24 h and 48 h post-whitefly exposure (PWFE) in whitefly resistant (FDH-228) and tolerant (Mac7) cotton plants as compared to susceptible plants of Coker-312. However, delayed expression was recorded at 72 h of PWFE in Coker-312 plants. In TRV based gene silencing experiment, silencing of the Mi-1.2-like gene, significantly enhanced the whitefly infestation on both whitefly-resistant and susceptible cotton genotypes. Based on these results, we conducted the evolutionary analysis of Mi-1.2-like orthologs among cotton, cassava, tomato, papaya, and cucumber hosts. This indicated that cotton associated Mi-1.2 like gene has a close relation with cassava and tomato. These results suggested that Mi-1.2-like R genes could be the potential candidate for deriving whitefly resistance response in cotton plants. [ABSTRACT FROM AUTHOR]

[Display omitted] • doublesex gene in Bemisia tabaci Asia II-1 genetic group is composed of six exons and five introns. • These exons are sex specifically spliced forming four male specific transcripts and one female specific transcript. • Btdsx regulates the expression of vitellogenin and vitellogenin receptor in B. tabaci. • dsRNA mediated knockdown of Btdsx in both female and males followed by mating resulted in significant decrease in fecundity and egg hatchability compared to control mating cross. • Knockdown of dsx also resulted in low frequency female specific deformities in the ovipositor. The silverleaf whitefly Bemisia tabaci is one of the most destructive of crop pests globally. In Northern India cotton is predominately infested by the Asia II-1 species of B. tabaci. Though B. tabaci exhibits unique haplodiploidy in its reproductive behavior, to date very little is known regarding its sex determination mechanism. Here, an in-depth characterization of the AsiaII-1 doublesex (Btdsx) gene, which has been implicated in sex determination in B. tabaci , indicates the inclusion of six exons and five introns. The pre-mRNA is shown to sex-specifically splice, producing four male isoforms and one female isoform. These Bt Dsx proteins share common DNA binding (OD1) domains whereas they differ at their C-termini. RT-qPCR analysis revealed a significantly higher expression of Btdsx in female adults compared to that in male adults and earlier developmental stages. Functional characterization of Btdsx through RNA interference (RNAi) resulted in a significant reduction in its expression in both sexes. Btdsx knockdown concomitantly resulted in up-regulation of the expression of vitellogenin (vg) and vitellogenin receptor (vgr) genes in males and their down-regulation in females. Btdsx knockdown followed by mating resulted in reduced fecundity and percent egg hatching; however, no impact was observed on the female: male ratios in the progeny obtained from knockdown parents. [ABSTRACT FROM AUTHOR]

Bemisia tabaci Gennadius biotypes B and Q are two of the most important worldwide agricultural insect pests. Genomic sequences of Type-2 B. tabaci chemosensory protein (BtabCSP2) were cloned and sequenced in B and Q biotypes, revealing key biotype-specific variations in the intron sequence. A Q260 sequence was found specifically in Q-BtabCSP2 and Cucumis melo LN692399, suggesting ancestral horizontal transfer of gene between the insect and the plant through bacteria. A cleaved amplified polymorphic sequences (CAPS) method was then developed to differentiate B and Q based on the sequence variation in exon of BtabCSP2 gene. The performances of CSP2-based CAPS for whitefly recognition were assessed using B. tabaci field collections from Shandong Province (P.R. China). Our SacII based CAPS method led to the same result compared to mitochondrial cytochrome oxidase-based CAPS method in the field collections. We therefore propose an explanation for CSP origin and a new rapid simple molecular method based on genomic DNA and chemosensory gene to differentiate accurately the B and Q whiteflies of the Bemisia complex around the world. [ABSTRACT FROM AUTHOR]

Semi-natural habitats in agricultural landscapes may support parasitoid populations that provide biocontrol services by suppressing populations of crop pests, but little is known about the spatial pattern and variability of these services at different levels of scale. Here we investigate the rarely studied phenomenon of early-season crop colonization by parasitoids and the relationship with the surrounding landscape. We assessed parasitism of whiteflies by placing whitefly infested cotton seedlings in remnant vegetation, arable land 25–125 m from remnant vegetation, and arable land further than 400 m from remnant vegetation. Twelve to twenty sentinel plants were exposed in a 25 × 25 m grid pattern in plots in each habitat. The experiment was conducted at 18 locations across two landscapes and repeated three times in a 2-week period in 2007 and 2008. Parasitism was observed during the first three days after the introduction of the whitefly infested seedlings and was in all cases caused by Encarsia spp. The mean number of parasitized whitefly per plant was 0.106 ± 0.025 and was highest on cotton plants placed in remnant vegetation, declining with increasing distance from remnant vegetation. A regression model with land use and meteorological variables received more statistical support from the data than models with only landscape and time period as factors. Parasitism levels were influenced by the proportion of remnant vegetation, grassland, as well as wind, temperature, dew point temperature and year. Early-season colonization of whitefly infested seedlings by parasitoids was erratic and characterized by large spatial (inter-plant and inter-plot) and temporal variation. Our study confirms that remnant vegetation function as reservoirs for parasitoids and that parasitoids can penetrate arable fields beyond 125 m within 3 days. However, variation in the occurrence of parasitism makes it difficult to predict parasitoid colonization at a specific place and time. Therefore, field-based scouting for pests and parasitoids is necessary, even in landscapes with a high biocontrol potential. [ABSTRACT FROM AUTHOR]

Given expectations for a booming usage of thiamethoxam and increasing availability of the promising biological agent Serangium japonicum for the control of Bemisia tabaci in China, an evaluation of their compatibility is crucial for integrated pest management (IPM). This study examined the lethal and sublethal effects of thiamethoxam on S . japonicum through three exposure routes. An acute toxicity bioassay showed that LC 50 values of thiamethoxam for S . japonicum through residue contact, egg-dip, and systemic treatment were 6.65, 4.37, and 2.43 mg AI L −1 , respectively. The prey consumption of S . japonicum given different densities of B . tabaci eggs under control, discontinuous, egg-dip and systemic exposure scenarios showed a good fit to a Type II functional response. Predation of S . japonicum was most affected under systemic exposure, followed by egg-dip, and discontinuous, which was only slightly affected. In all cases tested, however, predators recovered their predation capacity rapidly, either after 24 h of exposure or 24 h after the end of exposure. Thiamethoxam was highly toxic to S . japonicum regardless of exposure routes. Sublethal effects of thiamethoxam applied systemically or foliar both impaired the biological control of S . japonicum on B . tabaci . Therefore, thiamethoxam should be used with caution in IPM of B . tabaci . [ABSTRACT FROM AUTHOR]

The Zn hyperaccumulating plant, Noccaea caerulescens , was grown under controlled conditions at a range of Zn concentrations (0–1000 mg kg − 1 dwt. soil) to determine the effectiveness of hyperaccumulation in deterring the cabbage whitefly, Aleyrodes proletella , and to establish the relationship between levels of foliar Zn and glucosinolates (organic defence compounds). Two weeks after introducing A. proletella adults to the plants, next generation nymphs were quantified. This sucking insect caused minimal damage to plant tissue and did not affect foliar glucosinolate levels. Foliar Zn concentrations increased with increasing soil Zn application and reached a maximum of ~ 7000 mg kg − 1 . More whitefly nymphs were observed on plants as the foliar Zn concentration increased (up to ~ 3000 mg kg − 1 ) after which numbers declined. Zn was an explanatory variable in accumulated generalised linear regression after the variation in the data due to C/N ratio had been accounted for. Nymph numbers declined with increasing C/N ratio and increased with increasing N concentration. The highest glucosinolate concentrations were in shoots with the lowest Zn concentrations; this is consistent with the ‘trade-off’ hypothesis which states that elemental defence mechanisms allow for lowered organic defences. [ABSTRACT FROM AUTHOR]

Ultraviolet (UV) radiation directly regulates a multitude of herbivore life processes, in addition to indirectly affecting insect success via changes in plant chemistry and morphogenesis. Here we looked at plant and insect (aphid and whitefly) exposure to supplemental UV-A radiation in the glasshouse environment and investigated effects on insect population growth. Glasshouse grown peppers and eggplants were grown from seed inside cages covered by novel plastic filters, one transparent and the other opaque to UV-A radiation. At a 10-true leaf stage for peppers (53 days) and 4-true leaf stage for eggplants (34 days), plants were harvested for chemical analysis and infested by aphids and whiteflies, respectively. Clip-cages were used to introduce and monitor the insect fitness and populations of the pests studied. Insect pre-reproductive period, fecundity, fertility and intrinsic rate of natural increase were assessed. Crop growth was monitored weekly for 7 and 12 weeks throughout the crop cycle of peppers and eggplants, respectively. At the end of the insect fitness experiment, plants were harvested (68 days and 18-true leaf stage for peppers, and 104 days and 12-true leaf stage for eggplants) and leaves analysed for secondary metabolites, soluble carbohydrates, amino acids, total proteins and photosynthetic pigments. Our results demonstrate for the first time, that UV-A modulates plant chemistry with implications for insect pests. Both plant species responded directly to UV-A by producing shorter stems but this effect was only significant in pepper whilst UV-A did not affect the leaf area of either species. Importantly, in pepper, the UV-A treated plants contained higher contents of secondary metabolites, leaf soluble carbohydrates, free amino acids and total content of protein. Such changes in tissue chemistry may have indirectly promoted aphid performance. For eggplants, chlorophylls a and b, and carotenoid levels decreased with supplemental UV-A over the entire crop cycle but UV-A exposure did not affect leaf secondary metabolites. However, exposure to supplemental UV-A had a detrimental effect on whitefly development, fecundity and fertility presumably not mediated by plant cues as compounds implied in pest nutrition - proteins and sugars - were unaltered. [ABSTRACT FROM AUTHOR]

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Highlights: [•] PepLCV, a whitefly-transmitted begomovirus, is a severe constrain to pepper production. [•] Artificial screening methodology against PepLCV was standardized using microcage technique. [•] Bhut Jolokia was determined as a new source of resistance against PepLCV. [•] Inheritance study reveals a monogenic recessive resistance against PepLCV in Bhut Jolokia. [Copyright &y& Elsevier]

Highlights: [•] A bead-based array that detects plant viruses and their insect vectors is described. [•] The multiplexed array was shown to be highly specific, sensitive and reproducible. [•] Comparison with qPCR showed equal sensitivity of both methods. [•] The array may facilitate the improved management of invasive pests and diseases. [ABSTRACT FROM AUTHOR]

• A novel deep learning strategy for very small objects based on YOLOv4 backbones. • An image mosaicking and a fusion of hypothesized objects to classify whiteflies. • An annotated database of soybean leaf images with whiteflies and development stages. • Detection and classification results, with comparison with a state-of-art CNN. This paper presents a novel strategy to detect and classify adult whiteflies and five important related stages on images of detached soybean leaves. The whitefly Bemisia tabaci is a major pest in soybean crops, and by detecting, counting and differentiating its related life stages in field collected leaves control management decisions can be made. The proposed solution is based on a deep learning object detection algorithm (YOLOv4), modified into an specific new learning strategy with innovations on data augmentation, image mosaicking, and fusion of hypothesized object categories. A real and annotated dataset of images is provided from a controlled experiment infected with whitefly eggs having 121 images and 973 annotated objects. The experimental results showed a promising performance of the proposed system, reaching an f1-score of 0.87, in comparison with a single YOLOv4 algorithm that reached f1-score of 0.80. The overall strategy could be extended to work in other similar tasks for image based pest management. [ABSTRACT FROM AUTHOR]

Cassava plays a key role in the food security and economy of Cameroon, but its production is constrained by cassava mosaic disease (CMD). However, comprehensive surveys of CMD in Cameroon have been lacking. This study aimed at evaluating the current status of CMD and its whitefly vector. Field surveys were conducted in 2020 using a sampling, diagnostics and data storage protocol that has been harmonized across 10 West and Central African countries for ease of comparison. Thirty plants per field were assessed for CMD severity, whitefly abundance and source of infection. Surveys were conducted in 343 fields and confirmed the presence of CMD in all 10 regions of Cameroon. Among the 10,057 assessed plants, 33.07% were deemed healthy (asymptomatic). At the field level, only 6.7% fields were found to be healthy. The mean CMD incidence across the country was 66.93%, and the mean severity score was 2.28. The main mode of infection was likely through contaminated cuttings. The mean whitefly count per plant was 5.78. This study is the first countrywide survey of CMD in Cameroon and provides insights that can be useful for improving the country's CMD intervention and management strategies. • First countrywide survey of cassava mosaic disease (CMD) in Cameroon (343 fields). • CMD and whiteflies were recorded in all 10 regions of the country. • Mean CMD incidence was 66.93%, and mean whitefly count was 5.78 per plant. • Diseased cuttings were the main source of CMD infection. [ABSTRACT FROM AUTHOR]

Cassava whitefly are a group of cryptic species within the Bemisia tabaci sensu lato complex that causes significant damage to cassava in Africa. B. tabaci Sub-Saharan Africa 1 (SSA1) is the major species in the study region which transmits plant-virus diseases to cassava and causes direct feeding damage. Benefits from management of cassava viral diseases through deployment of resistant varieties are being undermined by their susceptibility to B. tabaci SSA1 and the problem is exacerbated by high populations of B. tabaci in cassava fields. To develop a clean seed system that is disease-free, the judicious use of insecticides is required to manage this pest and vector. This study evaluated the effect of timing of insecticide application on controlling B. tabaci SSA1 population abundance and damage to cassava. Field trials were carried out between 2017 and 2018 in Kamuli and Wakiso districts of Uganda using the widely available insecticide Imidacloprid. Three cassava cultivars (NAROCASS1, SAUTI, KBH/2002/026) were planted in a randomized complete block trial design replicated three times. The insecticide was applied in split-plots designated as: (i) no protection (NP), no insecticide applied (control), (ii) early protection (EP), insecticide applied 2 times between 0 and 4 months after planting, (iii) long protection (LP), insecticide applied 3 times between 0 and 8 months after planting, and (iv) total protection (TP), insecticide applied 4 times between 0 and 12 months after planting. Except for control plots, stem cuttings were first dipped into a diluted solution of Imidacloprid prior to planting. Bi-monthly data were collected on the B. tabaci population, feeding damage, cassava mosaic disease and cassava brown streak disease. Stem cuttings and root yields were determined at harvest. The marginal rate of return for each treatment was calculated to determine cost effectiveness. Insecticide application effectively reduced B. tabaci populations, feeding damage and disease spread. Cassava yield differed significantly with insecticide treatment and amongst cultivars. Root and stem yield losses of >60% was recorded in unprotected control plots. The marginal rate of return of the early protection (0–4 MAP) program was 163%. We discuss these findings and the implication for judicious use of insecticides as part of a cassava clean seed system. • Early use of Imidacloprid followed by two foliar applications significantly reduced whitefly populations. • Imidacloprid treatments resulted in low nymph densities, which prevented subsequent population build-up. • Effective whitefly control by early applications of Imidacloprid reduced damage and disease incidences. • Early crop protection with Imidacloprid resulted in highest tuber yields and economic benefits. • This whitefly-control strategy, therefore, is viable for East African cassava growers. [ABSTRACT FROM AUTHOR]

Cassava mosaic disease (CMD) is the main threat to cassava (Manihot esculenta Crantz) production in Benin. This study was conducted to assess CMD incidence, disease severity, and adult whitefly (Bemisia tabaci) populations in 11 regions of Benin. A total of 180 cassava fields across the country were assessed during June–December 2020 following the harmonized protocol of the Central and West African Virus Epidemiology program. Based on symptoms observation, CMD was present in all surveyed fields in Ouémé and Alibori regions. The highest disease incidence levels were observed in Malanville (100%), Kpomassè (86.67%), Kandi and Zagnanado (both 81.67%), Ségbanan (80%), and Avrankou (76.67%) districts. The highest mean severity scores were in Couffo (3.68), Mono (3.63), and Atlantique (3.33) regions, while the lowest was in Alibori (2.37). Adult whitefly populations (mean number/plant) were highest in Couffo (15.88) and Mono (13.00) regions and lowest in Donga (0.06). Significant relationships were found between CMD severity and whitefly abundance (P = 0.0010) but there was no significant relationship between whitefly numbers and CMD incidence (P = 0.0577). These findings indicate that CMD has expanded its range across Benin. They also provide a basis for designing a response strategy for the control of cassava virus diseases such as CMD. • One of the constraints for cassava production in Benin is cassava mosaic disease. • Cassava fields were surveyed for CMD and its vector throughout Benin. • The disease symptoms and CMVs vectors were found in all regions of Benin. • The incidence of CMD has reached 100% in Alibori region in northern Benin. • CMD is still expanding in new areas of cassava production across the country. [ABSTRACT FROM AUTHOR]

The success of integrated pest management programs depends on the use of feasible and efficient sampling plans. Considering that the citrus blackfly, Aleurocanthus woglumi Ashby (Hemiptera: Aleyrodidae), is an important citrus pest, the aim of this research was to develop a conventional sampling plan to assess adult populations of this insect in orange orchards. For this, we defined the sampling unit, number of samples, time and the cost of sampling. The third most apical leaf of the branch was the ideal unit to assess citrus blackfly adult densities and the sampling plan consisted of 58 samples. On average, the plan required 55.26 min to complete and costs US$ 1.78. The sampling plan developed here is an accurate, viable and low-cost tool that can be used in integrated pest managemant programs in orange orchards. Our methods can also be applied to study ecological and geographic parameters of this pest. [Display omitted] • Aleurocanthus woglumi is an important orange pest. • A conventional sampling plan for adults of A. woglumi was developed. • The assessments should be performed using the 3rd most apical leaf of the branches. • The sampling plan requires 58 samples per orchard. • The sampling plan is low cost (US$ 1.78), fast (55.26 min) and feasible. [ABSTRACT FROM AUTHOR]

• Novel two-stage solution for insects counting over leaves in the wild. • Fully convolutional regression network is proposed to estimate a probabilistic density map for the counting regression problem. • The estimated density map is validated for counting whiteflies in eggplant leaves. • The proposed method was compared with a baseline based on candidate object selection and classification approach. • This solution was embedded to be used in mobile devices in the wild. • Validation of the performance of the method with well-established quality metrics. Digitalization and automation of assessments in field trials are established practice for farming product development. The use of image-based methods has provided good results in different applications. Although these models can leverage some problems, they still perform poorly under real field conditions using mobile devices on complex applications. Among these applications, insect counting and detection is necessary for integrated pest management strategies in order to apply specific treatments at early infection stages to reduce economic losses and minimize chemical usage. Currently the counting task for the assessment of the degree of infestation is done manually by the farmer. Current state of the art object counting methods do not provide accurate counting in crowded images with overlapped or touching objects which is the case for insect counting images. This makes necessary to define novel approaches for insect counting. In this work, we propose a novel solution based on deep learning density map estimation to tackle insects counting in wild conditions. To this end, a fully convolutional regression network has been designed to accurately estimate a probabilistic density map for the counting regression problem. The estimated density map is then used for counting whiteflies in eggplant leaves. The proposed method was compared with a baseline based on candidate object selection and classification approach. The results for alive adult whitefly counting by means of density map estimation provided R2 = 0.97 for the counted insects in the main leaf of the image, that outperforms by far the baseline algorithm (R2 = 0.85) based on image processing methods for feature extraction and candidate selection and deep learning-based classifier. This solution was embedded to be used in mobile devices, and it has been gone for exhaustive validation tests, with diverse illumination conditions and background variability, over leaves taken at different heights, with different perspectives and even unfocused images, for the analyzed pest under real conditions. [ABSTRACT FROM AUTHOR]

Aleyrodomorpha, known as whiteflies, is an extremely specialized infraorder of tiny hemipteran insects, with relative scarcity of fossil records in the Mesozoic Lagerstätten. We herein describe and illustrate a new aleurodicine whitefly, Burmodicus monlyae Chen et Zhuo, sp. nov., based upon a fossil trapped in mid-Cretaceous Kachin amber, northern Myanmar. The new species can be easily discriminated from its congener by possessing a series of fore- and hind wing characters, e.g., fore wing with costal area and clavus with tip almost at same level, R branching distinctly basad of CuP ending, RP not ending at wing tip and almost at same level of CuA ending, and hind wing with RP just lightly longer than RA. Our find further adds new knowledge on the palaeo-biodiversity of early Aleyrodomorpha. [ABSTRACT FROM AUTHOR]

Abstract: Sap-sucking insects are important pests in agriculture and good models to study insect biology. The role of ecdysone pathway genes in the life history of this group of insects is largely unknown likely due to a lack of efficient gene silencing methods allowing functional genetic analyses. Here, we developed a new and high throughput method to silence whitefly genes using a leaf-mediated dsRNA feeding method. We have applied this method to explore the roles of genes within the molting hormone-ecdysone synthesis and signaling pathway for the survival, reproduction and development of whiteflies. Silencing of genes in the ecdysone pathway had a limited effect on the survival and fecundity of adult whiteflies. However, gene silencing reduced survival and delayed development of the whitefly during nymphal stages. These data suggest that the silencing method developed here provides a useful tool for functional gene discovery studies of sap-sucking insects, and further indicate the potential of regulating the ecdysone pathway in whitefly control. [Copyright &y& Elsevier]

Highlights: [•] Development of a TaqMan real-time PCR assay for specific detection of SLCV. [•] This qPCR assay is 1000 times more sensitive than conventional PCR. [•] Absolute quantitation of viral load in different squash organs and in viruliferous whiteflies. [•] In silico analysis shows suitability for detection of the western hemisphere SLCV. [Copyright &y& Elsevier]