Myzus Persicae Research Articles

Role of parasitoids and landscape structure in aphid population dynamics in winter canola

Three aphid species infest winter canola, Brassica napus L. fields in central Oklahoma and are serious pests: the cabbage aphid, Brevicoryne brassicae L., green peach aphid, Myzus persicae (Sulzer), and turnip aphid, Lipaphis pseudobrassicae (Davis). Mortality caused by parasitoids may be an important component of biological control of aphids in Oklahoma canola fields. Therefore, it is important to determine the effect of parasitoids on aphids in canola and the factors that affect it. We undertook a study during three consecutive growing seasons to: 1) estimate aphid suppression by parasitoids in each of 23 canola fields using cages that excluded natural enemies and cages that permitted access by parasitoids; and 2) evaluate how aphid parasitism in canola is related to the composition and configuration of the landscape surrounding each canola field. Parasitism was estimated using turnip aphid infested sentinel canola plants stationed in each field in autumn and in spring of each growing season. Two parasitoids with broad host ranges, Diaeretiella rapae (M’Intosh) and Aphelinus nigritus (Howard), parasitized turnip aphids in canola. There were fewer aphids and more parasitoids in cages that permitted access to parasitoids than in cages that excluded natural enemies. Partial redundancy analysis demonstrated that parasitism rate by D. rapae was positively related to landcover of wetlands and negatively related to contagion of patches. Parasitism by A. nigritus was positively but weakly associated with landcover of summer crops, but not with any other measured landscape variable. Wetlands in central Oklahoma agricultural landscapes apparently are habitat for aphid parasitoids from which they disperse to canola fields and parasitize aphids. Partial redundancy analysis showed that relative aphid density in fields was negatively related to parasitism by D. rapae. Results indicate that parasitoids suppress aphid infestations in canola fields and demonstrate potential for habitat management to improve biological control of aphids in canola.

Control of the Green Peach Aphid Insect, Myzus persicae and the Glassy Clover Snail, Monacha cartusiana (Müller) by using Fungus, Trichoderma yunnanense as a Safe Alternative to Pesticides and its Effect on Aminotransferase Enzymes Activity

Control of the Green Peach Aphid Insect, Myzus persicae and the Glassy Clover Snail, Monacha cartusiana (Müller) by using Fungus, Trichoderma yunnanense as a Safe Alternative to Pesticides and its Effect on Aminotransferase Enzymes Activity

The impact of thiamethoxam on the feeding and behavior of 2 soybean herbivore feeding guilds.

Over the past few decades, inadvertent consequences have stemmed from the intensified use of neonicotinoids in agroecosystems. Neonicotinoid applications can result in both positive (e.g., reduced persistent virus transmission) and negative (e.g., increased host susceptibility) repercussions exhibiting ambiguity for their use in crop production. In soybean, aspects of neonicotinoid usage such as the impact on nonpersistent virus transmission and efficacy against nontarget herbivores have not been addressed. This study evaluated the interaction between the neonicotinoid thiamethoxam and soybean variety and the impact on different pest feeding guilds. Feeding and behavioral bioassays were conducted in the laboratory to assess the effect of thiamethoxam on the mortality and weight gain of the defoliator, Chrysodeixis includens (Walker). Bioassays evaluated impacts dependent and independent of soybean tissue, in addition to both localized and systemic efficacy within the soybean plant. Additionally, using the electrical penetration graph technique (EPG), the probing behavior of 2 piercing-sucking pests, Aphis gossypii Glover and Myzus persicae (Sulzer), was observed. Results from defoliator bioassays revealed thiamethoxam had insecticidal activity against C. includens. Distinctions in thiamethoxam-related mortality between bioassays dependent and independent of soybean tissue (~98% versus ~30% mortality) indicate a contribution of the plant towards defoliator-related toxicity. Observations of defoliator feeding behavior showed a preference for untreated soybean tissue relative to thiamethoxam-treated tissue, suggesting a deterrent effect of thiamethoxam. EPG monitoring of probing behavior exhibited a minimal effect of thiamethoxam on piercing-sucking herbivores. Findings from this study suggest neonicotinoids like thiamethoxam may provide some benefit via insecticidal activity against nontarget defoliators.

Design, Synthesis, and Insecticidal Evaluation of Neonicotinoids with Conjugated Diene.

Neonicotinoid insecticides acting on the insect nicotinic acetylcholine receptors (nAChRs) play an essential role in contemporary pest control. In the present study, a series of novel neonicotinoid analogues with conjugated diene were synthesized. Bioassays indicated that compounds A3 and A12 had LC50 values of 1.26 and 1.24 mg/L against Myzus persicae, respectively, which were comparable to that of imidacloprid (IMI, LC50 = 0.78 mg/L). Density functional theory (DFT) calculations were performed to explain the differences in the insecticidal activities of target compounds. Molecular docking results indicate that compounds A3 and A12 interact favorably with Lymnaea stagnalis AChBP. The hydrolysis experiments confirmed that the stability of compounds A3 and A12 was enhanced in water.

Predicting the seasonal flight activity of Myzus persicae, the main aphid vector of Virus Yellows in sugar beet.

Virus Yellows (VY), a disease caused by several aphid-borne viruses, is a major threat to the global sugar beet production. Following the ban of neonicotinoid-based seed treatments against aphids in Europe, increased efforts are needed to monitor and forecast aphid population spread during the sugar beet growing season. In particular, predicting aphid flight seasonal activity could allow anticipation of the timing and intensity of crop colonisation and contribute to the proper implementation of management methods. Forecasts should be made early enough to assess risk, but can be updated as the season progresses to refine management. Based on a long-term suction-trap dataset gathered between 1978 and 2014, we built and evaluated a set of models to predict the flight activity features of the main VY vector, Myzus persicae, at any location in the French sugar beet production area (c. 4 × 105 ha). Flight onset dates, length of flight period and cumulative abundance of flying aphids were predicted using climatic and land-use predictors as well as geographical position. Our predictions outperformed current models published in the literature. The importance of the predictor variables varied according to the predicted flight feature but winter and early spring temperature always played a major role. Forecasts based on temperature were made more accurate by adding predictors related to aphid winter reservoirs. In addition, updating the model parameters to take advantage of new weather data acquired during the season improved the flight forecast. Our models can be used as a tool for the mitigation in sugar beet crops. © 2023 Society of Chemical Industry.

Pyrethroid and carbamate resistance in Czech populations of Myzus persicae (Sulzer) from oilseed rape.

Failures in controlling Myzus persicae by pyrethroids and carbamates have been observed in Czechia since 2018. Eleven populations collected from Czech oilseed rape fields during 2018-2021 were tested for susceptibility to 11 insecticides. The presence of a single nucleotide polymorphism (SNP) leading to knockdown resistance in M. persicae populations was screened using allelic discriminating quantitative real-time polymerase chain reaction (qPCR). The presence of mutations related with the resistance of M. persicae to pyrethroids and carbamates was detected by sequencing paratype voltage-gated sodium channel and acetylcholinesterase 2 genes, respectively. Resistance to alpha-cypermethrin and pirimicarb was detected in most of the tested populations. The L1014F mutation was detected in 44.5% of M. persicae individuals surviving the field-recommended dose of alpha-cypermethrin. Sequencing of partial para gene for paratype voltage-gated sodium channel detected five different SNPs leading to four amino acid substitutions (kdr L1014F; s-kdr M918L; s-kdr M918T; and L932F). No pyrethroid-sensitive genotype was detected. The S431F amino acid substitution conferring resistance to carbamates was detected in 11 of 20 individuals with different pyrethroid-resistance genotypes. Resistance of M. persicae to both pyrethroids and carbamates was detected in nine of 11 populations. High resistance of M. persicae was correlated with mutations of the sodium channel. Sulfoxaflor, flonicamid, and spirotetramat are proposed as effective compounds to control pyrethroid- and carbamate-resistant populations of M. persicae. © 2023 Society of Chemical Industry.

Peach–Potato Aphid Myzus persicae: Current Management Strategies, Challenges, and Proposed Solutions

The peach–potato aphid, Myzus persicae (Sulzer), is one of the most important pests of economic crops. It damages the plant directly by consuming nutrients and water and indirectly by transmitting plant viruses. This pest has the unenviable title of having resistance to more insecticides than any other herbivorous insect pest. Due to the development of its resistance to chemical pesticides, it is necessary to find other control options. Consequently, increased efforts worldwide have been undertaken to develop new management approaches for M. persicae. In this review, we highlight the problems associated with the peach–potato aphid, its economic importance, and current management approaches. This review also describes the challenges with current management approaches and their potential solutions, with special focus given to the evolution of insecticidal resistance and sustainable pest management strategies, such as biocontrol agents, entomopathogens, the use of natural plant-derived compounds, and cultural methods. Furthermore, this review provides some successful approaches from the above eco-friendly pest management strategies that show high efficacy against M. persicae.

Lethal and sublethal effects of lambda-cyhalothrin on Aphis fabae (Scopoli, 1763), Myzus persicae (Sulzer, 1776) and Acyrthosiphon pisum (Harris, 1776) (Hemiptera: Aphididae)

In this study, sublethal doses of lambda-cyhalothrin to the species Aphis fabae (Scopoli, 1763), Myzus persicae (Sulzer, 1776) and Acyrthosiphon pisum (Harris, 1776) (Hemiptera: Aphididae) were determined, and the effects of these doses on the life cycles of the species were revealed and evaluated. The lethal effects of different concentrations (0.3125, 0.625, 1.25, 2.5, 5, 10 and 20 µL L-1) prepared by distillated water of lambda-cyhalothrin on the species were determined according to Abbott. Based on the results obtained, the effects of LC30 and LC40 concentrations of the insecticide on the life cycles of the species were determined. The insecticide caused different mortality rates in the species. The sublethal concentrations of the insecticide were found to be effective for the life cycles of the species. In all three species, intrinsic rate of increase (rm), net reproduction rate (R0) and gross reproduction rate (GRR) values were found to decrease when insecticide was applied. The results will provide guidance to researchers working in this specific field. However, it would be beneficial to replicate this study under field conditions to obtain clear information.

Myzus persicae (Sulzer, 1776) (Hemiptera: Aphididae) popülasyonlarında neonikotinoid ve sentetik piretroid insektisitlerin tekli ve karışımlarına karşı direnç durumu

The peach potato aphid, Myzus persicae (Sulzer, 1776) (Hemiptera: Aphididae), a vector of many plant virus diseases, causes damage to its wide range of hosts by direct feeding. Chemical control has been the primary method to control this species, and the intensive use of insecticides has led to the development of resistance. In this study, conducted between the years 2017-2019, firstly resistance ratio of five M. persicae populations from Antalya, Türkiye were determined by leaf-dip bioassay method. The field populations showed significant resistance to thiamethoxam (between 201-332 fold) and lambda-cyhalothrin (between 50-103 fold) when compared to susceptible population. To identify whether resistance mediated by mutations in sodium channel and nicotinic acetylcholine receptor, DNA regions that encompass “mutation hot-spot” were sequenced. This revealed no population contained R81T mutation that has been previously linked with neonicotinoid resistance. As to synthetic pyrethroid resistance, the L1014F kdr mutation was fixed in all field populations. This study is the first description of kdr mutation in M. persicae populations from Türkiye. Bioassay results also indicated that the toxicity of thiamethoxam and lambda-cyhalothrin mixture was higher than that of lambda-cyhalothrin alone. Our findings can make significant contributions to M. persicae resistance management.

The Spatiotemporal Distribution, Abundance, and Seasonal Dynamics of Cotton-Infesting Aphids in the Southern U.S.

Cotton leafroll dwarf virus (CLRDV) is an emerging aphid-borne pathogen infecting cotton, Gossypium hirsutum L., in the southern United States (U.S.). The cotton aphid, Aphis gossypii Glover, infests cotton annually and is the only known vector to transmit CLRDV to cotton. Seven other species have been reported to feed on, but not often infest, cotton: Protaphis middletonii Thomas, Aphis craccivora Koch, Aphis fabae Scopoli, Macrosiphum euphorbiae Thomas, Myzus persicae Sulzer, Rhopalosiphum rufiabdominale Sasaki, and Smynthurodes betae Westwood. These seven have not been studied in cotton, but due to their potential epidemiological importance, an understanding of the intra- and inter-annual variations of these species is needed. In 2020 and 2021, aphids were monitored from North Carolina to Texas using pan traps around cotton fields. All of the species known to infest cotton, excluding A. fabae, were detected in this study. Protaphis middletonii and A. gossypii were the most abundant species identified. The five other species of aphids captured were consistently low throughout the study and, with the exception of R. rufiabdominale, were not detected at all locations. The abundance, distribution, and seasonal dynamics of cotton-infesting aphids across the southern U.S. are discussed.

Sublethal Effects of Flonicamid on Life Table of Myzus persicae (Sulzer)

The green peach aphid, Myzus persicae (Sulzer) (Aphididae: Hemiptera) is a cosmopolitan polyphagous pest of more than five hundred plant species belonging to at least forty different plant families including several economically important agricultural crops. The sublethal effect of LC25 concentration of flonicamid on M. persicae was assessed by using an age-stage two-sex life table approach for integrated management of this pest. A leaf-dip bioassay showed that flonicamid was very toxic to the adults of M. persicae at 48 h with the calculated LC25 concentration value of 0.0115 g a.i./L. The adults (parental generation) of M. persicae exposed to the LC25 concentration (sublethal dose) of flonicamid showed inhibitory effects on the life history traits across its generations such as reduction in adult longevity and fecundity of parental generation (F0); shortening the durations of fifth instar nymphs, adult female longevity, oviposition period, total longevity and fecundity of F1 & F2 generations. On the other hand, stimulatory effects were observed on the duration of first, second, third, and fourth instar nymphs; and pre-adults in F2 generation in the flonicamid-treated aphids. Consistently with the effects on individual traits, a higher mean generation time (T) and shorter intrinsic rate of increase (r), finite rate of increase (λ), and net reproductive rate (R0) of F2 generation were observed in the flonicamid treated aphids, although r, λ, R0, T, and gross reproductive rate (GRR) of F1 generation were not significantly affected. The findings revealed the exposure of parental adults of M. persicae to sublethal concentration of flonicamid could induce hormetic (both inhibitory and stimulatory) effects on their succeeding generations. This study is useful for assessing the overall effects of flonicamid on M. persicae. The hormetic effects should be considered when it used flonicamid in the integrated management of M. persicae in crop fields.

Seasonal Dynamics of Aphid Flights and Cotton Leafroll Dwarf Virus Spread in Alabama.

Cotton leafroll dwarf virus (CLRDV) is an introduced Polerovirus (Family: Solemoviridae) of cotton, Gossypium hirsutum L., in the U.S. The only vector known to transmit this virus to cotton is the cotton aphid, Aphis gossypii Glover; however, there are seven other species of aphids (Hemiptera: Aphididae) reported to colonize cotton in the southeastern U.S.: Protaphis middletonii (Thomas), Rhopalosiphum rufiabdominale (Sasaki), Aphis craccivora Koch, Macrosiphum euphorbiae Thomas, Myzus persicae (Sulzer), Smythurodes betae Westwood, and Aphis fabae Scopoli. Little to no information is available on annual population dynamics of these species in the southeastern U.S. The timing of CLRDV spread to cotton plantings is also unknown. The objective of this study was to monitor the population dynamics of eight cotton-feeding aphid species concurrent with the spread of CLRDV at three different locations in Alabama. Aphids were monitored weekly for two years with yellow pan traps, and sentinel plants were deployed weekly to monitor CLRDV spread throughout the cotton-growing season. During the two years, most CLRDV spread at all locations occurred when A. gossypii was actively dispersing in the field. Early season spread at sites in south and central Alabama, when A. gossypii was not abundant, suggests additional aphid vectors are possible.

The effects of different Charleston pepper cultivars on the demographic parameters and the antioxidant levels of Myzus persicae (Sulzer, 1776) (Hemiptera: Aphididae)

Host plant diversity causes differences in the biology and adaptation of insects. In this study, variations in some biological properties and adaptive antioxidative response of Myzus persicae (Sulzer,1776) (Hemiptera: Aphididae) on five Charleston pepper, Capsicum annuum L. (Solanaceae) cultivars were investigated under laboratory conditions (25±1°C, 60±5% RH). The lowest intrinsic rate of increase (r = 0.193 d-1) of M. persicae was estimated in the tested cohort fed with the Kanyon cultivar, while the highest intrinsic rate of increase (r = 0.248 d-1) was found on the Tufan cultivar. The cohort fed with Safkan cultivar exhibited the highest levels of GST-CDNB and EST-PNPA at 562.80 and 207.64 nmol/mg protein, respectively, whereas the cohort fed with Kanyon cultivar showed the lowest levels at 317.04 and 132.14 nmol/mg protein, respectively. Analysis of life table parameters and enzymatic/non-enzymatic antioxidant levels of M. persicae showed that among the cultivars we tested, the Tufan cultivar was the most preferred host by M. persicae, while Kanyon cultivar was a less suitable host.

Evaluation of Resistance of Oilseed Rape Genotypes to Turnip Yellows Virus

Turnip yellows virus (TuYV), is one of the most important pathogens of oilseed rape, which has caused enormous yield losses in all growing regions of the world in recent years. Therefore, there is a need for resistant varieties for sustainable crop protection. We have investigated the resistance of known varieties and newly developed advanced-breeding lines of oilseed rape to TuYV in greenhouse and field trials. We have analysed the TuYV titre of individual genotypes inoculated with the virus using viruliferous aphids Myzus persicae. The genotypes ‘DK Temptation’ and ‘Rescator’ had the lowest and highest virus titres, respectively, and were used as resistant and susceptible models for comparative analyses with other genotypes. In the greenhouse, the best results were obtained with the genotypes ‘OP-8143 DH’ (2.94 × 105 copies), OP-BN-72 (3.29 × 105 copies), ‘Navajo’ (3.58 × 105 copies) and ‘SG-C 21215’ (4.09 × 105 copies), which reached virus titres about 2 times higher than the minimum virus concentration measured in ‘DK Temptation’ (1.80 × 105 copies). In the field trials, the genotypes ‘Navajo’ (3.39 × 105 copies), ‘OP-8148 DH’ (4.44 × 105 copies), ‘SG-C 21215’ (6.80 × 105 copies) and OP-8480 (7.19 × 105 copies) had the lowest virus titres and reached about 3 times the virus titre of DK Temptation (2.54 × 105 copies). Both trials showed that at least two commercial varieties (e.g., DK Temptation, Navajo) and three advanced breeding lines (e.g., OP-8143 DH, OP-BN-72, SG-C 21215) had low titres of the virus after TuYV infection. This indicates a high level of resistance to TuYV in ‘Navajo’ or the newly developed breeding lines and the basis of resistance is probably different from R54 (as in ‘DK Temptation’). Furthermore, the greenhouse trials together with RT -qPCR-based virus titre analysis could be a cost-effective and efficient method to assess the level of resistance of a given genotype to TuYV infection compared to the field trials. However, further research is needed to identify the underlying mechanisms causing this difference in susceptibility.

Effects of different industrial cannabis (Cannabis sativa (Linnaeus 1753) (Cannabaceae)) genotype extracts on Diuraphis noxia Kurdjumov, 1913 Myzus persicae Sulzer, 1776 and Aphis fabae Scopoli, 1763 (Hemiptera: Aphididae)

In this study, the effect of methanol extracts of three different genotypes (Narlısaray, Kavacık, Maltepe) of Cannabis sativa L. on Diuraphis noxia Kurdjumov, Myzus persicae (Sulzer) and Aphis fabae (Scopoli) (Hemiptera: Aphididae) were investigated. In the first stage of the study, 10% concentrations of each cannabis extract were applied on the 2nd and 3rd nymphal stages of aphid species by spraying method. After the end of 24 - 48 and 72 hours of the applications, the alive and dead individuals were recorded and mortality rates were determined. In the second stage, the genotype with the highest effect was used in dose-death trials and LD50 and LD90 values at different doses (2.5%, 5%, 7.5% and 10%) were specified. In the census after 72 hours, Narlısaray genotype showed the highest mortality rate with 54.04% on D. noxia. While the effect of Kavacık genotype on M. persicae was found as 23.13%, the highest toxicity record of the same genotype was determined on A. fabae (as 91.76%). According to the dose measurement studies of Kavacık genotype on A. fabae, LD50 and LD90 values were calculated to be 0.33 and 0.110 (mg/individual), respectively. At the results of study, it has been observed that extracts of different genotypes of the industrial cannabis plant are found effective on aphid species and it is thought that they can be used in controlling of these pests.

Signal and Nutritional Effects of Mixed Diets on Reproduction of a Predatory Ladybird, Cheilomenes propinqua.

It is known that food has a double impact on females of predatory ladybirds: qualitative signal effect (the onset of oogenesis) and quantitative nutritional effect (the increase in oogenesis intensity). We compared the patterns of these effects by feeding Cheilomenes propinqua females on mixed diets: unlimited low-quality prey (eggs of the grain moth Sitotroga cerealella) and limited high-quality prey (the green peach aphid Myzus persicae: 0, 2, 10, and 50 aphids per day). About half of the females fed only on the grain moth eggs oviposited and their fecundity was very low. Daily consumption of 2 aphids increased the proportion of egg-laying females whereas only consumption of 10 aphids increased their mean fecundity. Thus, the threshold of the signal effect was lower than that of the nutritional effect. As applied to mass rearing, we conclude that the addition of high-quality prey to low-quality food causes a substantial increase in egg production, although the economic feasibility of this method is not clear. Regarding biological control of pests by preventing colonization, we conclude that the fecundity of C. propinqua females supplied with the grain moth eggs in the absence of aphids will be low but the appearance of pests will cause a proportional increase in the mean fecundity of ladybirds.

Predation and Control Effect of Eupeodes corollae Fabricius (Diptera: Syrphidae) on Leguminous Plant Aphids

Eupeodes corollae Fabricius, one of the most common predatory natural enemies of agricultural ecosystems, plays an important role in aphid control, but its ability to prey on and control leguminous plant aphids has not been systematically studied. Our study on the spawning and predation preferences, predatory function responses, searching efficiency, and prevention and control capabilities of E. corollae on Aphis craccivora Koch, Myzus persicae Sulzer, and Megoura japonica Matsumura showed that the spawning and predation preferences of E. corollae were consistent and that it preferred A. craccivora for both spawning and predation. The Holling’s type II response was observed in the second- and third-instar larvae of E. corollae to the three species of aphids. For A. craccivora, M. persicae, and M. japonica, the maximum daily predations (1/Th) of second-instar larvae were 83.33, 166.67, and 47.62, respectively, and those of third-instar larvae were 142.86, 200.00, and 90.91, respectively. For A. craccivora, the aphid population decline rates for the 1:1000 and 1:2000 treatment ratios were close to 100% 12 days after the release of E. corollae; for M. persicae, the aphid population decline rates for the 1:2000, 1:4000, and 1:6000 ratios were 98.80%, 96.46%, and 92.89%, respectively. For M. japonica, the aphid population decline rates for the 1:250, 1:500, and 1:1000 ratios all reached 100%. These results provide good theoretical and application value for the management of aphids and the optimization of the ecological biocontrol service functions of E. corollae.

Preference and performance of the generalist aphid Myzus persicae on closely and distantly related plant species

AbstractThe ability of herbivorous insects to discriminate suitable host plants for the development of their progeny is not homogenous. Herbivores with broader diets show weaker correlation between oviposition preference and offspring performance in comparison with specialist insects. The neural constraints hypothesis postulates that due to neural limitation, generalist insects would have greater difficulty in processing a large number of stimuli from diverse host plants. Under this framework, it is expected that generalists would be more efficient in discriminating suitable plants when faced with more similar stimuli from closely related plants (simplified environment), and less efficient when faced with more diverse stimuli from unrelated plants (complex environment). In this study, we evaluated this in the generalist aphid Myzus persicae (Sulzer) (Hemiptera: Aphididae). Preference was evaluated as the aphid's ability to discriminate between congeneric plant species or between plants from different families. The congeneric host plants were the cultivated potato, Solanum tuberosum L., the wild potato, Solanum commersonii Dunal, tomato, Solanum lycopersicum L., and eggplant, Solanum melongena L. (Solanaceae). The plant species of different families used were spinach, Spinacia oleracea L. (Amaranthaceae), squash, Cucurbita maxima Duchesne (Cucurbitaceae), and basil, Ocimum basilicum L. (Lamiaceae). Performance was evaluated as the population growth in one generation on whole‐plant conditions and on excised leaves. The results showed positive correlations between settlement and larviposition preferences and the performance of M. persicae for all comparisons between unrelated plant species. Positive correlations between preference and performance were also observed for two of the three comparisons between congeneric plants. These results indicate that M. persicae can efficiently discriminate between suitable plants for their progeny regardless of the degree of relatedness of the plants, which is at odds with the neural constraints hypothesis. The results contribute to the knowledge of host selection mechanisms in generalist herbivores, particularly in an underrepresented insect group.

Plants affect the horizontal transmission of a new densovirus infecting the green peach aphid Myzus persicae by modulating honeydew production.

In a tritrophic context of plant-insect-entomopathogen, plants play important roles in modulating the interaction of insects and their pathogenic viruses. Currently, the influence of plants on the transmission of insect viruses has been mainly studied on baculoviruses and some RNA viruses, whereas the impact of plants on other insect viruses is largely unknown. Here, we identified a new densovirus infecting the green peach aphid Myzus persicae and tested whether and how host plants influence the transmission of the aphid densovirus. The complete single-stranded DNA genome of the virus, M. persicae densovirus 2, is 5727nt and contains inverted terminal repeats. Transcription and phylogenetic analysis indicated that the virus was distinct from other a few identified aphid densoviruses. The virus abundance was detected highly in the intestinal tract of aphids, compared with the lower level of it in other tissues including head, embryo, and epidermis. Cabbage and pepper plants had no obvious effect on the vertical transmission and saliva-mediated horizontal transmission of the virus. However, the honeydew-mediated horizontal transmission among aphids highly depended on host plants (65% on cabbages versus 17% on peppers). Although the virus concentration in the honeydew produced by aphids between 2 plants was similar, the honeydew production of the infected aphids reared on peppers was dramatically reduced. Taken together, our results provide evidence that plants influence the horizontal transmission of a new densovirus in an aphid population by modulating honeydew secretion of aphids, suggesting plants may manipulate the spread of an aphid-pathogenic densovirus in nature.

Transcriptomic and Proteomic Analyses of Myzus persicae Carrying Brassica Yellows Virus.

Viruses in the genus Polerovirus infect a wide range of crop plants and cause severe economic crop losses. BrYV belongs to the genus Polerovirus and is transmitted by Myzus persicae. However, the changes in transcriptome and proteome profiles of M. persicae during viral infection are unclear. Here, RNA-Seq and TMT-based quantitative proteomic analysis were performed to compare the differences between viruliferous and nonviruliferous aphids. In total, 1266 DEGs were identified at the level of transcription with 980 DEGs being upregulated and 286 downregulated in viruliferous aphids. At the protein level, among the 18 DEPs identified, the number of upregulated proteins in viruliferous aphids was twice that of the downregulated DEPs. Enrichment analysis indicated that these DEGs and DEPs were mainly involved in epidermal protein synthesis, phosphorylation, and various metabolic processes. Interestingly, the expressions of a number of cuticle proteins and tubulins were upregulated in viruliferous aphids. Taken together, our study revealed the complex regulatory network between BrYV and its vector M. persicae from the perspective of omics. These findings should be of great benefit to screening key factors involved in the process of virus circulation in aphids and provide new insights for BrYV prevention via vector control in the field.