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The pea aphid, Acyrthosiphon pisum, is a paradigmatic photoperiodic species that exhibits a remarkable annual life cycle, which is tightly coupled to the seasonal changes in day length. During spring and summer, characterised by longer days, aphid populations consist exclusively of viviparous females that reproduce parthenogenetically. When autumn comes and the days shorten, aphids switch their reproductive mode and generate males and oviparous sexual females, which mate and produce cold-resistant eggs that overwinter and survive the unfavourable season. While the photoperiodic responses have been well described, the nature of the timing mechanisms which underlie day length discrimination are still not completely understood. Experiments from the 1960's suggested that aphids rely on an 'hourglass' clock measuring the elapsed time during the dark night by accumulating a biochemical factor, which reaches a critical threshold at a certain night length and triggers the switch in reproduction mode. However, the photoperiodic responses of aphids can also be attributed to a strongly dampened circadian clock. Recent studies have uncovered the molecular components and the location of the circadian clock in the brain of the pea aphid and revealed that it is well connected to the neurohormonal system controlling aphid reproduction. We provide an overview of the putative mechanisms of photoperiodic control in aphids, from the photoreceptors involved in this process to the circadian clock and the neuroendocrine system. [ABSTRACT FROM AUTHOR]

Coccinellids (Coleoptera) are important natural enemies of pests in agroecosystems. However, worldwide, native species face several threats, including landscape simplification, biological invasions, and climate change. In Central Chile, one of the global biodiversity hotspots, coccinellid communities are very diverse and are composed mostly of native species, which are most common in less disturbed habitats. In alfalfa fields, native coccinellids play a crucial role in the biological control of aphids, even when they are less abundant than exotics. However, in the last 2 decades, native species in this crop have declined in abundance and diversity. Our long‐lasting field and laboratory studies have shown that this decline is associated with: (1) the invasion of Harmonia axyridis (Pallas), which has superior competitive abilities and escapes more from parasitism; (2) the simplification of agricultural landscapes, loss of natural habitats, and urbanization; and (3) increasing environmental temperatures and decreasing precipitation. The decline in native coccinellid populations has resulted in a loss of taxonomic and functional diversity of assemblages, which may jeopardize biological control. Alfalfa fields and natural and semi‐natural habitats may offer an opportunity for the conservation of native coccinellids in agricultural landscapes. Such conservation might be achieved with better management of alfalfa fields and surrounding areas. [ABSTRACT FROM AUTHOR]

Simple Summary: Aphidoletes aphidimyza (Rondani) is an important predatory insect, primarily preying on aphids. The effective control of diapause in A. aphidimyza is a crucial practical issue in the field of biological pest control and large-scale artificial insect breeding. Previous research has shown that, in the European strain of A. aphidimyza, diapause occurs during the larval stage in the cocoon, it has a day-long response, and it enters diapause when the day length decreases. In this study, we evaluated the effects of photoperiod and temperature on the incidence of diapause in A. aphidimyza. We found that the diapause occurs in the cocooning larvae stage, and the highest diapause rate was recorded at under 15 °C and 10L:14D photoperiod conditions. Transcriptome sequencing analysis showed that differentially expressed genes were mainly enriched in the glucose metabolism pathway. The aphidophagous gall midge, Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae), a dominant natural enemy of aphids, has been used as a biological control agent in many countries to control aphids in greenhouses. To identify key factors that induce diapause in A. aphidimyza, we evaluated the effects of photoperiod and temperature on the incidence of diapause in A. aphidimyza under laboratory conditions. The results showed that temperature and photoperiod had significant impacts on development and diapause in A. aphidimyza. Low temperatures and a short photoperiod inhibited development, while high temperatures and a long photoperiod promoted development. Temperatures above 20 °C and a photoperiod greater than 14 h prevented diapause in A. aphidimyza. However, the highest diapause rate was recorded at under 15 °C and 10L:14D photoperiod conditions. At 15 °C, the first to third larvae were sensitive to a short photoperiod at any stage, and a short photoperiod had a cumulative effect on diapause induction. The longer the larvae received short light exposure, the higher the diapause rate appeared to be. Transcriptome sequencing analysis at different stages of diapause showed that differentially expressed genes were mainly enriched in the glucose metabolism pathway. Physiological and biochemical analyses showed that diapausing A. aphidimyza reduced water content; accumulated glycogen, trehalose, sorbitol, and triglycerides; and gradually reduced trehalose and triglyceride contents in the body with the extension of diapause time. Glycogen may be used as a source of energy, but sorbitol is usually used as a cryoprotectant. This study provided results on aspects of diapause in A. aphidimyza, providing data and theoretical support for promoting its commercial breeding and in-depth research on the molecular mechanisms underlying diapause regulation. [ABSTRACT FROM AUTHOR]

Peach-potato aphids, Myzus persicae Sulzer (Hemiptera:Aphididae), and cabbage aphids, Brevicoryne brassicae Linnaeus (Hemiptera:Aphididae), are herbivorous insects of significant agricultural importance. Aphids can harbour a range of non-essential (facultative) endosymbiotic bacteria that confer multiple costs and benefits to the host aphid. A key endosymbiont-derived phenotype is protection against parasitoid wasps, and this protective phenotype has been associated with several defensive enodsymbionts. In recent years greater emphasis has been placed on developing alternative pest management strategies, including the increased use of natural enemies such as parasitoids wasps. For the success of aphid control strategies to be estimated the presence of defensive endosymbionts that can potentially disrupt the success of biocontrol agents needs to be determined in natural aphid populations. Here, we sampled aphids and mummies (parasitised aphids) from an important rapeseed production region in Germany and used multiplex PCR assays to characterise the endosymbiont communities. We found that aphids rarely harboured facultative endosymbionts, with 3.6% of M. persicae and 0% of B. brassicae populations forming facultative endosymbiont associations. This is comparable with endosymbiont prevalence described for M. persicae populations surveyed in Australia, Europe, Chile, and USA where endosymbiont infection frequencies range form 0–2%, but is in contrast with observations from China where M. persicae populations have more abundant and diverse endosymbiotic communities (endosymbionts present in over 50% of aphid populations). [ABSTRACT FROM AUTHOR]

Simple Summary: Acetamiprid, commonly used in agriculture to control aphids, faces the problem of resistance development in certain aphid species. To investigate the insect mechanisms involved in the adaptation process to acetamiprid, we compared the gene expression and microbial profiles of a pea aphid strain selected with acetamiprid (RS) with those of a non-selected strain (SS) using advanced omics techniques. The overall analysis revealed significant changes in the expression of genes involved in carbon and fatty acid metabolism in RS compared to those of SS aphids. In particular, we found increased expression of specific genes related to the synthesis of the components of the epidermal wax layer, suggesting that adaptation to acetamiprid involves the synthesis of a thicker protective layer. Additionally, subtle shifts in the bacterial composition of RS were detected. These results contribute valuable insights into the mechanisms underlying the pea aphid's response to acetamiprid exposure. Such understanding is essential for informing future research efforts and developing more effective strategies to control this pest. Acetamiprid is a broad-spectrum neonicotinoid insecticide used in agriculture to control aphids. While recent studies have documented resistance to acetamiprid in several aphid species, the underlying mechanisms are still not fully understood. In this study, we analyzed the transcriptome and metatranscriptome of a laboratory strain of the pea aphid, Acyrthosiphon pisum (Harris, 1776), with reduced susceptibility to acetamiprid after nine generations of exposure to identify candidate genes and the microbiome involved in the adaptation process. Sequencing of the transcriptome of both selected (RS) and non-selected (SS) strains allowed the identification of 14,858 genes and 4938 new transcripts. Most of the differentially expressed genes were associated with catalytic activities and metabolic pathways involving carbon and fatty acids. Specifically, alcohol-forming fatty acyl-CoA reductase (FAR) and acyl-CoA synthetase (ACSF2), both involved in the synthesis of epidermal wax layer components, were significantly upregulated in RS, suggesting that adaptation to acetamiprid involves the synthesis of a thicker protective layer. Metatranscriptomic analyses revealed subtle shifts in the microbiome of RS. These results contribute to a deeper understanding of acetamiprid adaptation by the pea aphid and provide new insights for aphid control strategies. [ABSTRACT FROM AUTHOR]

Honeydew from Hemipteran insects serves as carbohydrate source to beneficial insects but also to various microorganisms. Microbial volatile organic compounds (mVOCs) may play diverse roles in herbivore–microbe–natural enemy interactions. However, the functional significance of mVOCs from aphid honeydew remains largely unclear. In this study, a total of seven cultivable bacteria from Sitobion miscanthi honeydew have been isolated and identified based on 16S rRNA technique, which included Lysinibacillus fusiformis, Erwinia aphidicola, E. tasmaniensis, Acinetobacter bereziniae, Klebsiella quasipneumoniae subsp. Similipneumoniae, Staphylococcus capitis and Bacillus safensis subsp. safensis. One bacterial strain, L. fusiformis MH1, was found to be most attractive to Aphidius gifuensis parasitic wasp in Y-tube olfactometer. Two compounds, namely 1-ethyl-2-methylbenzene and 2-butyl-1-octanol, were emitted from L. fusiformis MH1 and were attractive to A. gifuensis and identified by using coupled gas chromatography–electroantennography and coupled gas chromatography with mass spectrometry. Application of bacterial and mVOCs formulations in crop field resulted in significant aphid abundance decrease associated with higher parasitism rates compared with control. Our results indicated that some microbes in aphid honeydew could manipulate the herbivore–natural enemy interactions and could be developed as a novel alternative for environmentally friendly biological control of aphids. [ABSTRACT FROM AUTHOR]

Pandora neoaphidis is a common entomopathogenic fungus on Sitobion avenae, which is an important aphid pest on cereals in Europe. Pandora neoaphidis is known to cause epizootics (i.e. an unusually high prevalence of infected hosts) and the rapid collapse of aphid populations. We developed a weather-driven mechanistic model of the winter wheat-S. avenae-P. neoaphidis system to simulate the dynamics from spring to harvest. Aphid immigration was fixed at a rate that would lead to a pest outbreak, if not controlled by the fungus. We estimated the biocontrol efficacy by running pair-wise simulations, one with and one without the fungus. Uncertainty in model parameters and variation in weather was included, resulting in a range of simulation outcomes, and a global sensitivity analysis was performed. We identified two key understudied parameters that require more extensive experimental data collection to better assess the fungus biocontrol, namely the fungus transmission efficiency and the decay of cadaver, which defines the time window for possible disease transmission. The parameters with the largest influence on the improvement in yield were the weather, the lethal time of exposed aphids, the fungus transmission efficiency, and the humidity threshold for fungus development, while the fungus inoculum in the chosen range (between 10 and 70% of immigrant aphids carrying the fungus) was less influential. The model suggests that epizootics occurring early, around Zadoks growth stage (GS) 61, would lead to successful biocontrol, while later epizootics (GS 73) were a necessary but insufficient condition for success. These model predictions were based on the prevalence of cadavers only, not of exposed (i.e. infected but yet non-symptomatic) aphids, which in practice would be costly to monitor. The model suggests that practical Integrated Pest Management could thus benefit from including the cadavers prevalence in a monitoring program. We argue for further research to experimentally estimate these cadaver thresholds. [ABSTRACT FROM AUTHOR]

Wheat aphids are major pests of wheat and a significant threat to global food security. Eupeodes corollae Fabricius is one of the dominant species of wheat field hoverflies, but its ability and role in wheat aphid control lack systematic research. This study on the predatory function responses of E. corollae to Rhopalosiphum padi Linnaeus, Schizaphis graminum Rondani, and Sitobion miscanthi, Takahashi showed that the maximum daily predation (1/Th) of 2nd instar E. corollae larvae was 166.67, 125.00, and 142.86, and that of 3rd instar larvae was 333.33, 250.00, and 250.00, respectively. The cage simulation test indicated that the wheat aphid population decline rate was 100% at the 60th hour of inoculation of 3rd instar E. corollae larvae at a 1:100 ratio. Eupeodes corollae exhibited a predatory relationship with all three wheat aphid species in the wheat fields of Hebei Province, China, and the corrected predation detection rates of E. corollae larvae against R. padi, S. graminum, and S. miscanthi were 12.36%, 1.08%, and 28.77% in 2022, and 6.74%, 0.82%, and 37.56% in 2023, respectively. The results of this study clarify the predatory ability of E. corollae on wheat aphids and the predatory relationship between them and provide technical support for the management of wheat aphids using the bio-control ecological service function of E. corollae. [ABSTRACT FROM AUTHOR]

Simple Summary: Pesticide poisoning is a particular concern for honeybee farms. In addition to causing mortality due to acute, subacute, and chronic phenomena, poisonings debilitate honeybees by making them more susceptible to damage by other pathogens and environmental stressors. For this reason, it is important to seek solutions that can mitigate the effects of these phenomena. In this laboratory study, it was shown how dietary supplementation of the bergamot polyphenolic fraction is able to mitigate the toxic effects of flupyradifurone, also increasing the survival probability of honeybees. Flupyradifurone (FLU) is a butenolide insecticide that has come onto the market relatively recently. It is used in agriculture to control aphids, psyllids, and whiteflies. Toxicity studies have decreed its low toxicity to honeybees. However, recent research has challenged these claims; oral exposure to the pesticide can lead to behavioral abnormalities and in the worst cases, lethal phenomena. Compounds with antioxidant activity, such as flavonoids and polyphenols, have been shown to protect against the toxic effects of pesticides. The aim of this research was to evaluate the possible protective effect of the bergamot polyphenolic fraction (BPF) against behavioral abnormalities and lethality induced by toxic doses of FLU orally administered to honeybees under laboratory conditions. Honeybees were assigned to experimental groups in which two toxic doses of FLU, 50 mg/L and 100 mg/L were administered. In other replicates, three doses (1, 2 and 5 mg/kg) of the bergamot polyphenolic fraction (BPF) were added to the above toxic doses. In the experimental groups intoxicated with FLU at the highest dose tested, all caged subjects (20 individuals) died within the second day of administration. The survival probability of the groups to which the BPF was added was compared to that of the groups to which only the toxic doses of FLU were administered. The mortality rate in the BPF groups was statistically lower (p < 0.05) than in the intoxicated groups; in addition, a lower percentage of individuals exhibited behavioral abnormalities. According to this research, the ingestion of the BPF attenuates the harmful effects of FLU. Further studies are needed before proposing BPF incorporation into the honeybees' diet, but there already seem to be beneficial effects associated with its intake. [ABSTRACT FROM AUTHOR]

One of the major insect pests in Pisum sativum L. (is Acyrthosiphon pisum Harris (Hemiptera: pests in Pisum sativum L. (Hemiptera: Aphididae) is Acyrthosiphon pisum Harris (Hemiptera: Aphididae). An effective strategy for aphid control is the resistant host plant use. The current study aimed to identify resistance mechanisms and assess biochemical and morphological markers of pea aphid resistance in pea accessions. Meteorological variables affected the pea aphid density, which positively correlated with temperature, while precipitation amount and humidity negatively impacted. The aphid number was significantly and positively associated with the leaf area and the nitrogen content but negatively correlated with calcium and phosphorus levels. The pea aphid-resistant cultivars L 123-7-11, L 128-1and L 125-5 had small leaf areas, and high phosphorus and calcium content but a low nitrogen level. In the mutual influence of the plant indicators, phosphorus concentration had the highest negative impact on pea aphid density, followed by calcium. The plant marker inclusion in the pea breeding process is an efficient tool for a substantial selection program improvement for aphid resistance. Therefore, resistant host plants are essential tools promoting considerable selection program improvement for aphid resistance in the P. sativum breeding process and helping develop sustainable and environmentally friendly agriculture. [ABSTRACT FROM AUTHOR]

Aphids are a major pest of cropping systems throughout the world. In most cases, crop aphids are controlled with broad‐spectrum insecticides; although generally very effective at preventing yield loss, this approach risks non‐target damage to beneficial organisms. In the last 20 years, a number of selective insecticides have become available to control aphids while minimising harm to other arthropods. Previous studies have found that two such insecticides, flonicamid and afidopyropen, cause only low‐level acute mortality impacts on aphid parasitoids in Australian grain crops. However, little research has examined the sub‐lethal effects of these chemicals, which could induce various physiological changes that impact pest control. We hypothesised that both flonicamid and afidopyropen have negative effects that extend beyond the immediate acute mortality previously published. To test this hypothesis, we undertook a series of experiments to determine the effects of flonicamid and afidopyropen, along with the synthetic pyrethroid gamma‐cyhalothrin, on aphid parasitism (mummification) rate, emergence rate of the next generation and the next generation sex ratio in three important aphid parasitoids, Aphidius colemani (Viereck), Diaeretiella rapae (M'Intosh) and Aphelinus abdominalis (Dalman). Analogous with previous research, our acute toxicity bioassays showed that all three insecticides had low (<30%) mortality impacts. Although sub‐lethal impacts could not be assessed for D. rapae due to the low level of aphid parasitism by that species, our findings showed negative impacts on fecundity in surviving A. abdominalis and A. colemani. Of particular note is the increase in International Organisation for Biological Control ratings to moderate (30%–80% mortality and/or reproductive reduction) when mortality and reduced fecundity effects were combined to determine overall fitness impacts. Gamma‐cyhalothrin typically resulted in higher negative impacts on A. abdominalis and A. colemani (compared with flonicamid and afidopyropen); however, quite surprisingly, these impacts were not rated as highly toxic. Taken together, our results suggest that, even when sub‐lethal impacts are considered, flonicamid and afidopyropen are useful tools for farmers targeting aphid populations while minimising the non‐target impacts on parasitoids. We recommend semi‐field and/or field trials to further assess the impacts of these insecticides on aphid parasitoid populations. [ABSTRACT FROM AUTHOR]

Warming temperate winters are resulting in increased insect winter activity. With modern agroecosystems largely homogenous, characterised by low floral diversity, competitive interactions may arise between flower-visiting species, with potential implications for the ecosystem services they provide (e.g. biological control and pollination). Flower strips may be implemented during winter months to support flower-visiting insects and enhance ecosystem service provision. Employing field trials conducted in Brittany, France between 2019 and 2021 and laboratory cage experiments, the current study examined the impact of winter flower strips on aphid biological control performed by parasitoid wasps and the potential for competitive interactions between winter-active parasitoids and pollinators. Results revealed that parasitism rate was not enhanced by the presence of winter flower strips. This lack of effect was not the consequence of pollinator presence, and the current study found no effect of pollinator abundance on parasitism rate. Flower strips may thus be implemented during winter months to support nectar-feeding insects when floral resources are scarce, with no evidence of exploitative competition between pollinators and parasitoids, nor a detrimental impact on biological control provision. [ABSTRACT FROM AUTHOR]

Hippodamia convergens—the convergent lady beetle, has been used extensively in augmentative biological control of aphids, thrips, and whiteflies across its native range in North America, and was introduced into South America in the 1950s. Overwintering H. convergens populations from its native western range in the United States are commercially collected and released across its current range in the eastern USA, with little knowledge of the effectiveness of its augmentative biological control. Here we use a novel ddRADseq‐based SNP/haplotype discovery approach to estimate its range‐wide population diversity, differentiation, and recent evolutionary history. Our results indicate (1) significant population differentiation among eastern USA, western USA, and South American populations of H. convergens, with (2) little to no detectable recent admixture between them, despite repeated population augmentation, and (3) continued recent population size expansion across its range. These results contradict previous findings using microsatellite markers. In light of these new findings, the implications for the effectiveness of augmentative biological control using H. convergens are discussed. Additionally, because quantifying the non‐target effects of augmentative biological control is a difficult problem in migratory beetles, our results could serve as a cornerstone in improving and predicting the efficacy of future releases of H. convergens across its range. [ABSTRACT FROM AUTHOR]

Simple Summary: Biological control is an important method for pest management. Natural enemies not only prey on pests directly but also release predation risk cues to pests, causing physiological and behavioral changes in them, reducing their fitness, and ultimately leading to a decrease in their population. Aphis gossypii is an important insect pest of melon and many other crops worldwide. This study examined the predation risk effects of Menochilus sexmaculatus, which is abundant in agricultural areas of southern China, on A. gossypii. The results showed that the presence of M. sexmaculatus significantly altered the host preference of the aphids. The longevity of the aphids was shortened, and the reproductive period and offspring production were decreased significantly after exposure to M. sexmaculatus for 24 h. The enzyme activities of SOD and CAT were increased, and the content of MDA in aphids also showed an increase under the predation risk of M. sexmaculatus. Through a combined GC-MS and behavioral response experiment, the results showed that alkane compounds may mediate the predation risk. The results will offer an alternative strategy for utilizing these alkanes as repellents to manage aphids. Predation risk posed by natural enemies can alter pest performance. In our previous study, we found Menochilus sexmaculatus provides risk cues to melon aphids, resulting in increased numbers of winged aphids. However, the effects of predation risk on multiple traits including behavior, physiology, growth rate, and reproductive capacity of pests are not clear. This study examined the effects of predation risk on host preference, the activities of two important defense enzymes (CAT and SOD), longevity, and offspring production. The Y-tube trial results showed that the risk of M. sexmaculatus significantly altered the host preference of the aphids, leading to avoidance behavior. When exposed to M. sexmaculatus for a long period (24 h), the reproductive period and offspring production were significantly decreased, and adult longevity was significantly shortened. The defense enzyme activities of SOD and CAT, as well as the MDA content (which is considered a marker of oxidative stress and cellular damage) in the aphids, significantly increased under M. sexmaculatus risk. The compounds of M. sexmaculatus extracted with n-hexane and volatile compounds collected with HS-SPME were analyzed by GC-MS, and when combined with the behavior response experiment, the results showed that the alkane compounds n-henicosane, n-docosane, n-tricosane, n-pentacosane, and n-hentriacontane may contribute to the impact of predation risk. The results will be helpful in the comprehensive evaluation of the ability of lady beetles to affect the aphid population, and provide new ideas for using these compounds in aphid control. [ABSTRACT FROM AUTHOR]

Aphids (Chaetosiphon fragaefolii; Aphididae) are one of the pests that attack Strawberry (Fragaria x ananassa) plants that can transmit viruses infecting Strawberry (Fragaria x ananassa) plants. Symptoms caused by Chaetosiphon fragaefolii include sooty mold, stunted growth and twisted, curly and yellow stems. Farmers will experience losses caused by aphids (Chaetosiphon fragaefolii) symptoms such as a significant reduction in strawberry (Fragaria x ananassa) yields. The purpose of this literature study examines how to control aphids (Chaetosiphon fragaefolii) that attack Strawberry (Fragaria x ananassa) plants through natural ingredients. The results for controlling aphids (Chaetosiphon fragaefolii) through natural materials are 4, namely: Entomopathogenic fungi: Beaubevia bassiana and Metarizium sp., Parasitoids: Aphelinus varipes, Predators: family Syrphidae, family Asilidae, Orius insidiosus, Cycloneda sanguinea, Eriopis connexa and Coleomegilla quadrifasciata, Organic Pesticides: neem leaves with a concentration of 35 (g/l water) and mortality of 8.76 heads, while papaya leaves use a concentration of 30 ml/liter of water. [ABSTRACT FROM AUTHOR]

Simple Summary: Aphis gossypii is an important pest that harms lilies and limits the development of the lily industry. Improving host plant resistance is an effective and environmentally friendly method for aphid control. We studied the resistance of 16 lily cultivars and 2 wild lily species to A. gossypii and the biological characteristics of their leaves. Among the 18 tested lily plants, 'Palazzo', 'Nymph', 'Cameleon', and Lilium lancifolium showed strong resistance. The analysis of the correlation between the thickness of leaf palisade tissue and the number of greenhouse aphids reveals a significant negative correlation. This indicates that the thicker palisade tissue may be responsible for the observed resistance. Identifying these lilies is important for managing aphid populations and provides additional solutions for lily-integrated pest management. Lilies (Lilium spp.) are famous bulb flowers worldwide, with high ornamental value. Aphid damage has seriously constrained the development of the lily industry. In this study, the aphid resistance of 16 lily cultivars and 2 wild lily species was characterized in the field and greenhouse. Leaf color parameters, stomatal density and size, thickness of leaf layers, leaf waxy content, and leaf water content were determined to explore the constitutive resistance of lilies. The results show that there was a significant positive correlation between the number of aphids in the field and in the greenhouse (p ≤ 0.05, r = 0.47). This indicated that the level of aphid infestation in both the field and the greenhouse is generally consistent across different types of lily plants. Among these 18 lilies, 'Palazzo', 'Nymph', 'Cameleon' and L. lancifolium were resistant to A. gossypii, while 'Black Beauty' and 'Magnefique' had poor resistance. The correlation analysis results showed that the number of aphids was negatively correlated with leaf abaxial surface a*, stomatal size, water content, and thickness of leaf palisade tissue and positively correlated with leaf distal axial surface b*, C*, and waxy content. Among them, the correlation between the number of aphids and the thickness of leaf palisade tissue reached a significant level (p ≤ 0.05, r = −0.521). This indicated that the thickness of the palisade tissue of lily leaves might be an important factor influencing the proliferation of aphids. This study not only screened out aphid-resistant lilies but also established a crucial research foundation for the targeted breeding and molecular breeding of lilies with aphid resistance. [ABSTRACT FROM AUTHOR]

Simple Summary: The woolly apple aphid (Eriosoma lanigerum) is a worldwide pest that causes damage to shoots, branches, trunks, and roots and reduces the capacity of apple trees to sprout and bloom. Even though this pest has a diverse guild of natural enemies, the parasitoid Aphelinus mali and the European earwig (Forficula auricularia) are the ones that have the most potential to regulate this pest. In our study we assessed the impact of earwig releases over time on woolly apple aphid populations. To do this, we released earwigs once per season in consecutive years and we compared woolly apple aphid abundance with respect to a control treatment (without earwig release). Overall, we found that earwig releases reduced the size of the colonies, but this effect was only evident from the second year onwards. These results highlighted the importance of considering time on augmentative biological control strategies. Nature-based solutions, such as biological control, can strongly contribute to reducing the use of plant protection products. In our study, we assessed the effect of augmentative releases of the European earwig (Forficula auricularia) to control the woolly apple aphid (Eriosoma lanigerum), a worldwide pest that causes serious damage to apple trees. The trials were carried out in two organic apple orchards located in Catalonia (NE Spain) from 2017 to 2020. Two treatments were compared: with vs. without earwig release. For the treatment, 30 earwigs per tree were released by means of a corrugated cardboard shelter. These releases were performed once per season and were repeated every year. We periodically assessed the length of the woolly apple aphid colonies, the number of colonies per tree, the percentage of aphids parasitized by Aphelinus mali, and the number of earwigs per shelter. Our results showed that earwig releases reduced the length of the colonies, but this effect was noticeable only for the second year onwards. Moreover, we found that those releases were compatible with A. mali. Overall, we demonstrated the positive impact of earwig releases on the woolly apple aphid control and the importance of considering time on augmentative biological control strategies. [ABSTRACT FROM AUTHOR]

Background: Leaf-associated microbes play an important role in plant development and response to exogenous stress. Insect herbivores are known to alter the phyllosphere microbiome. However, whether the host plant's defense against insects is related to the phyllosphere microbiome remains mostly elusive. Here, we investigated bacterial communities in the phyllosphere and endosphere of eight wheat cultivars with differing aphid resistance, grown in the same farmland. Results: The bacterial community in both the phyllosphere and endosphere showed significant differences among most wheat cultivars. The phyllosphere was connected to more complex and stable microbial networks than the endosphere in most wheat cultivars. Moreover, the genera Pantoea, Massilia, and Pseudomonas were found to play a major role in shaping the microbial community in the wheat phyllosphere. Additionally, wheat plants showed phenotype-specific associations with the genera Massilia and Pseudomonas. The abundance of the genus Exiguobacterium in the phyllosphere exhibited a significant negative correlation with the aphid hazard grade in the wheat plants. Conclusion: Communities of leaf-associated microbes in wheat plants were mainly driven by the host genotype. Members of the genus Exiguobacterium may have adverse effects on wheat aphids. Our findings provide new clues supporting the development of aphid control strategies based on phyllosphere microbiome engineering. [ABSTRACT FROM AUTHOR]

Insect communities consist of species from several trophic levels that have to forage for suitable resources among and within larger patches of nonresources. To locate their resources, insects use diverse stimuli, including olfactory, visual, acoustic, tactile and gustatory cues. While most research has focused on cues derived from plants and other insects, there is mounting evidence that insects also respond to volatile organic compounds (VOCs) emitted by microorganisms. However, to date little is known about how the olfactory response of insects within and across different trophic levels is affected by bacterial VOCs. In this study, we used Y‐tube bioassays and chemical analysis of VOCs to assess how VOCs emitted by bacteria affect the olfactory response of insects of the same and different trophic levels. Experiments were performed using two aphid species (Amphorophora idaei Börner and Myzus persicae var. nicotianae Blackman), three primary parasitoid species (Aphidius colemani Viereck, A. ervi Haliday, and A. matricariae Viereck), and two hyperparasitoid species (Asaphes suspensus Nees and Dendrocerus aphidum Rondani). Olfactory responses were evaluated for three bacterial strains (Bacillus pumilus ST18.16/133, Curtobacterium sp. ST18.16/085, and Staphylococcus saprophyticus ST18.16/160) that were isolated from the habitat of the insects. Results revealed that insects from all trophic levels responded to bacterial volatiles, but olfactory responses varied between and within trophic levels. All bacteria produced the same set of volatile compounds, but often in different relative concentrations. For 11 of these volatiles we found contrasting correlations between their concentration and the behavior of the primary parasitoids and hyperparasitoids. Furthermore, olfactometer experiments on three of these compounds confirmed the contrasting olfactory responses of primary parasitoids and hyperparasitoids. The potential of these findings for the development of novel semiochemical‐based strategies to improve biological aphid control has been discussed. [ABSTRACT FROM AUTHOR]

Plant taxonomic and functional diversity promotes interactions at higher trophic levels, but the contribution of functional diversity effects to multitrophic interactions and ecosystem functioning remains unclear. In agroecosystems, flower strips can be sown to promote biodiversity and associated services, but their plant composition is poorly considered from a functional diversity perspective so as to promote multitrophic interactions.In a field experiment, aphid biological control was compared across contrasting flower strip mixtures, over a 4‐year arable crop rotation. The effects of plants providing food resources, that is nectar and legumes supporting alternative hosts and prey, and the effects of plant species richness and functional dispersion were investigated on the biological control of aphid populations.In general, increases in the percentage of plant cover providing nectar and alternative prey (Fabaceae) to natural enemies increased predator–prey ratios and aphid parasitism and decreased aphid population growth rates. These effects however depended on the crop species.Species richness and the functional dispersion of traits involved in plant–arthropod interactions were of lesser importance, and the directions of their effects were crop‐specific.Synthesis and applications. These findings provide useful insight for designing perennial plant mixtures for creating or restoring habitats supporting aphid regulation. It is not adequate to sow any mixture containing simply flowering plants. Plant mixtures should comprise a large proportion of plant species supporting alternative prey, like legumes, and species producing nectar being easily accessible to natural enemies (corollas with nondeep nectar). To be efficient over a crop rotation, with aphids being present at different seasons, these nectar resources should be provided throughout the year thanks to a diversity of plant flowering periods. [ABSTRACT FROM AUTHOR]

The devastating impact of chemical pesticides has prompted a shift towards sustainable agricultural pest management, such as biological control with natural enemies. In recent years, commercialization advancements have enabled the suppression of pest populations through augmentative releases of biological control agents, with natural enemies being a major tactic. China has successfully implemented natural-enemy-based biocontrol strategies, particularly for controlling aphids and lepidopterans. This article provides a comprehensive overview of the state-of-the-art natural-enemy-based biocontrol against arthropod pests in tobacco in China, including practical achievements in mass-rearing methods, augmentative release strategies, and the wide-scale use of natural enemies. Current and potential future challenges for natural-enemy-based biocontrol in China are also discussed. [ABSTRACT FROM AUTHOR]

Macrosiphoniella sanborni is a widespread pest of Chrysanthemum morifolium that causes significant damage to world floriculture. Chemical insecticides and biological methods of control have a number of disadvantages that can be improved by using oligonucleotide insecticides. In this article, we present, for the first time, the results of using oligonucleotide insecticides, for which the target sequence is an internal transcribed spacer (ITS) in a polycistronic rRNA transcript. The mortality of wingless aphid individuals after a Macsan-11 treatment was recorded at a level of 67.15 ± 3.32% 7 days after a single treatment with a solution at a concentration of 100 ng/μL and 97.38 ± 2.49% 7 days after a double treatment with a solution of the same concentration and a daily interval. The contact use of the control oligonucleotide (ACTG)2ACT-11. as well as the oligonucleotide insecticides Macsan-11(3′) and Macsan-11(5′) was not accompanied by insect mortality. Given the high variability in the internal transcribed spacer, which has proven to be a promising target for the action of oligonucleotide insecticides, it is possible to create selective preparations. This study showed the prospects of ribosomal insect pest genes as targets for the action of olinscides, and also demonstrated the high specificity of such insecticidal agents. [ABSTRACT FROM AUTHOR]

The purpose of this study was to clone S‐adenosylmethionine synthase (BtSAMS) from Balsas teosinte (Zea mays ssp. parviglumis) and investigate its function via heterologous expression in Arabidopsis plants. The BtSAMS coding sequence was cloned and its length is 1185 bp. The expression of BtSAMS in Z. mays ssp. parviglumis was a 12.2‐fold increase after aphid infestation. Transgenic Arabidopsis plants heterologously expressing BtSAMS were generated and their morphological characters were observed. A prolonged vegetative growth period was displayed by BtSAMS‐OX plants. The more and longer trichomes were observed on the upper surface of BtSAMS seedlings. The ethylene content in BtSAMS‐OX plants was not significantly different compared with the untransformed controls. These BtSAMS‐OX transgenic plants showed greater resistance to peach aphids compared with the untransformed control plants. Peach aphids appeared to prefer the untransformed controls in that aphids number reduced by more than 50% on BtSAMS plants compared to controls. When sprayed with the insecticide avi‐imidacloprid, the number of peach aphids decreased on BtSAMS‐OX plants and untransformed controls by 91.6% and 80.5%, respectively. Peach aphids also showed lower reproduction ability when forced to feed on the transgenic plants. The number of newly born nymphs on BtSAMS plants was less than 50% of that on the untransformed control. We therefore propose that BtSAMS may be a suitable candidate gene to confer resistance to peach aphids in plants. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Thermal performance within predator–prey systems may have profound effects on species interactions under climate change. However, how the thermal response of predators and prey to climate change affects their interactions is still understudied.To examine the responses of a predator–prey system to climate change, we constructed a biologically detailed stage‐structured population dynamic model using aphids (prey) and ladybirds (predator) as a model system. We explore the system's dynamics across the entire feasible parameter space of annual mean temperature and seasonality. Within this space, we explore all qualitatively possible scenarios of thermal performance mismatches to gain insight into how these affect the interacting species' responses to climatic change.We find that, generally, warmer and less seasonal climates are the most favourable climate conditions for both species. Our results also indicate that predation always has a stronger effect on aphid abundance than the climate in tropical and subtropical regions for all the thermal performance mismatch scenarios. Furthermore, predation's (biotic) effect on prey abundance will generally decrease relative to the effect of climate (abiotic) when future climates become warmer and more seasonal.Our research highlights that the effects of increasing seasonality are consistent with climate having a proportionally larger impact on species pairs with different thermal performances than predation. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Many ants and hemipterans are bound by a mutualistic relationship (trophobiosis) which represents an ecological keystone: ants receive food (honeydew) providing different kinds of protection. Partner protection against arthropod natural enemies is considered to be frequent and to interfere with biological control strategies of hemipteran pests.We carried out an ant‐exclusion field experiment in a fava bean (Vicia faba) plantation in Italy to monitor the abundance and behaviour of the ants (Plagiolepis pygmaea, Tetramorium semilaeve and the exotic Nylanderia jaegerskioeldi) and their relationship with facultative mutualist (Aphis fabae) and non‐mutualist (Megoura viciae) aphids, the arthropod natural enemies of the aphids, and extrafloral nectaries.Ants concentrated their activity on the attendance of facultative mutualist aphids much more than on the extrafloral nectaries. The ant‐exclusion treatment had no effect on the abundance of M. viciae and on the parasitization rate of A. fabae, while it reduced the abundance of A. fabae, aphid predators, and aphid parasitoids.Our results demonstrate that ant attendance does not imply the protection of aphids from arthropod natural enemies and suggest that the identity of the ant species involved is important for the outcome. As relatively few species have been studied in this regard, extending our knowledge to the role of more ant species is desirable to understand the ecology and evolution of ant‐aphid mutualisms and to refine integrated control strategies of aphid pests. [ABSTRACT FROM AUTHOR]

The aim of this research was to assess the efficacy of some predators worked as a biocontrol tool against the navel orange aphid species (Aphis gossypii (Glover), Aphis citricola (van der Goot), Myzus persicae (Sulzer), and Aphis craccivora Koch.) during a period of two seasons in 2021 and 2022. Aphis gossypii and Aphis citricola are the two main species of aphid discovered on navel orange plants. In the two seasons of the study, there were three abundance peaks of Aphis gossypii. In 2021, the numbers recorded in the third week in April and May, as well as the second week in June were 370, 450 and 454 individuals/40 leaves and recorded 281, 386, and 500 individuals during the first and fourth weeks of April and the fourth week of May in 2022, respectively. Meanwhile, A. citricola had two abundance peaks in both seasons: in 2021 (181 and 98 individuals/40 leaves) and in 2022 (245 and 295 individuals/40 leaves). Coccinella undecimpunctata L., Chrysoperla carnea Steph, C. septempunctata, Metasyrphus corollae Fand Cydonia vicina isis were the most common predators discovered on navel orange trees.. A few number of Paederus alfierii (Koch) and true spiders were the most common predators caught in navel orange trees. On navel orange trees, these predators recorded two peaks in two seasons (73 and 77 predators/40 leaves) during the first season, and (83 and 88 predators/40 leaves) during the second season, respectively. Two predators, C. undecimpunctata and C. carnea, that prey on A. gossypii were researched from a biological perspective at 21±1°C and 65± 5% R.H. C. undecimpunctata and C. carnea took 23.49 ± 1.40 and 25.01 ± 2.63 days, respectively, to develop from egg hatching to adult exclusion. The total consumption rate per C. undecimpunctata and C. carnea larva fed on A. gossypii were 567.50 ± 6.90 and 587.63 ± 9.27 when fed on A. gossypii. During their larval stages, C. undecimpunctata and C. carnea females generally lay around 315.85±5.17 and 321.52±6.19 eggs. [ABSTRACT FROM AUTHOR]

Simple Summary: The host-alternating aphid Semiaphis heraclei (Hemiptera: Aphididae) is the dominant pest of its primary host plant—honeysuckle (Lonicera japonica). As the initial generation on honeysuckles each year, the sexual generation is a key target in aphid control. Understanding the mechanism underlying chemical communication between sexual aphids could be helpful for exploring olfactory stimulus-based male trapping techniques. In this study, the morphology of antennae and the types, sizes, numbers, and distribution of sensilla on the male and sexual female antennae of S. heraclei were investigated by means of scanning electron microscopy. The male antennae were dramatically longer than those of sexual females and the flagellum length contributed to the different antennal length between the two sexes. Four of five sensillum types or subtypes present in both sexes were enlarged in males. In addition, trichoid sensilla subtype I were more abundant on male antennae than on sexual female antennae. In particular, secondary rhinaria were found to be male specific. These sex-biased traits could be of great importance in the perception of sex pheromones. Our findings provide insight into the olfactory sensing mechanism of sexual individuals to assist in pest control. Sexual generation is an important generation in the life cycle of host-alternating aphids, and its population size determines the intensity of the peak in the next spring. Although male trapping techniques based on olfactory stimuli have been successfully established in the field, the biological basis of olfactory perception in males is unclear. In this study, we compared the morphology of antennae and the types, sizes, numbers, and distribution of sensilla between males and sexual females in the host-alternating aphid Semiaphis heraclei (Hemiptera: Aphididae). We found that flagellum length differentiation contributed to the majority of the sexual dimorphism of antennae. Most sensillum types or subtypes, including trichoid sensilla subtype I, campaniform sensilla, and primary rhinaria subtypes I and II, were enlarged in males. In addition, males bore more trichoid sensilla subtype I than sexual females. In particular, secondary rhinaria were present in males only and could not be detected in sexual females. These results revealed the structural basis of male olfactory perception. Our findings provide insight into the mechanism underlying chemical communication between sexual aphids and could thus be useful for pest control. [ABSTRACT FROM AUTHOR]

Acyrthosiphon pisum Harris (Hemiptera: Aphididae) is a globally distributed and economically important aphid pest of leguminous crops including peas, broad beans, and alfalfa. Infestations weaken plants directly by feeding, and indirectly, by the transmission of yield-affecting plant viruses. Although pea aphid control strategies largely rely on the application of insecticides, cases of insecticide resistance under applied conditions have not yet been described. Here we investigated the molecular basis of high levels of pyrethroid resistance (up to >180-fold) in two strains of A. pisum, PYR-R1 and VR, collected in the field in France and Italy, respectively. Foliar bioassays revealed significant synergistic effects between deltamethrin and piperonyl butoxide (a cytochrome P450 (P450) inhibitor), and, to a lesser extent, S,S,Stributyl phosphorotrithioate (an esterase inhibitor). P450 and esterase activities in both resistant strains were significantly higher compared to an insecticide susceptible reference strain SUS-1. Target-site resistance mutations in the voltage-gated sodium channel known to confer pyrethroid resistance in other aphid pest species were not detected in either resistant strain. However, transcriptome profiling identified the P450 gene CYP6CY12 as highly over-expressed in the resistant PYR-R1 strain compared to the SUS-1 strain, and real-time quantitative PCR showed that this gene is also significantly overexpressed (>30-fold) in the VR strain. Functional expression of recombinant CYP6CY12 revealed its catalytic capacity to hydroxylate deltamethrin, thus confirming its causal role in pyrethroid resistance. Our study uncovered a P450-mediated mechanism of pyrethroid resistance in A. pisum for the first time and will inform future resistance management tactics to control this pest. [ABSTRACT FROM AUTHOR]

Cotton aphid, Aphis gossypii Glover is a cosmopolitan pest which causes huge damage by sucking a vital content of plants, it also transmit viral diseases in various field and horticultural crops. Due to development of resistance to insecticides and the environmental hazard it poses, more emphasis is being directed on biological control of cotton aphid. Continuous rearing of host insects is a key in biological control experiments. Of late, potted cotton plants are being extensively used for the rearing of cotton aphids. This method is cumbersome and requires more time and space. The other methods viz., rearing on excised cotton leaves and artificial diet are not suitable for rearing in large numbers. Hence, the present studies were aimed to find out an easy and reliable method for rearing. A simple rearing technique based on a host, Hibiscus cannabinus L. of Malvaceae family, is found effective for continuous rearing of cotton aphids throughout the year. Here, we assessed the developmental periods and population change of aphids as temperature dependent parameters. Among the different temperatures tested, 24 °C is found most suitable to produce nymphs and wingless adults in large numbers. For the production of winged adults, rearing at 27 °C is observed most suitable. This technique has certain advantages as it requires less space, is easy to maintain, incurs less cost and ensures clear visibility of all the instars for counting. This technique would help researchers in continuous rearing of A. gossypii for use in biological control and other studies. [ABSTRACT FROM AUTHOR]

Simple Summary: The English grain aphid, Sitobion avenae, is one of the major pests and disease vectors of wheat crops. In this study, E75, a key gene associated with ecdysone signal pathway, was identified and cloned from S. avenae. Functional characterization of E75 confirmed its role in the regulation of growth, development, and molting process of aphids. This finding offers a potential molecular target for the subsequent development of genetic-based biopesticides for aphid control. Ecdysteroid hormones are key regulators of insect development and metamorphosis. Ecdysone-inducible E75, a major component of insect ecdysone signaling pathway, has been well characterized in holometabolous insects, however, barely in hemimetabolous species. In this study, a total of four full-length E75 cDNAs from the English grain aphid, Sitobion avenae, were identified, cloned, and characterized. The four SaE75 cDNAs contained 3048, 2625, 2505, and 2179 bp open reading frames (ORF), encoding 1015, 874, 856, and 835 amino acids, respectively. Temporal expression profiles showed that SaE75 expression was low in adult stages, while high in pseudo embryo and nymphal stages. SaE75 was differentially expressed between winged and wingless morphs. RNAi-mediated suppression of SaE75 led to substantial biological impacts, including mortality and molting defects. As for the pleiotropic effects on downstream ecdysone pathway genes, SaHr3 (hormone receptor like in 46) was significantly up-regulated, while Sabr-c (broad-complex core protein gene) and Saftz-f1 (transcription factor 1) were significantly down-regulated. These combined results not only shed light on the regulatory role of E75 in the ecdysone signaling pathway, but also provide a potential novel target for the long-term sustainable management of S. avenae, a devastating global grain pest. [ABSTRACT FROM AUTHOR]

Simple Summary: The biological control of aphids by aphid-eating lady beetles (coccinellids) is often hampered by aphid-tending ants or aggressive, invasive ants foraging for food; aggressive species, such as the imported fire ant, may attack and kill lady beetle larvae. This study tested the hypothesis that wax-secreting coccinellid larvae are less susceptible than non-wax-secreting coccinellid larvae to fire ant aggression. Laboratory experiments were set up using bird cherry-oat aphid nymphs and adults (as prey for coccinellids) on barley leaves with either coccinellid species with or without fire ant workers. Results revealed that the presence of fire ants reduced aphid predation by non-wax-secreting but not wax-secreting larvae. The frequency of fire ant attacks was greater on non-wax-secreting larvae; the mortality was significantly greater for non-wax-secreting larvae. The wax covering over coccinellid larvae reduced fire ant aggression. Unexpectedly, coccinellid larvae with the wax cover removed did not suffer greater fire ant attacks or increased mortality. In conclusion, the wax cover and, perhaps, the volatile or non-volatile compounds in the wax and on the integument of wax-secreting coccinellid larvae reduce fire ant aggression. Further research could identify the wax compounds and determine their role as potential repellents or irritants against fire ants. The biological control of aphids by aphidophagous coccinellids is often hampered by aphid-tending ants or aggressive, invasive ants foraging for food. Aggressive species such as the imported fire ant Solenopsis invicta Buren may attack and kill coccinellid larvae. This study tested the hypothesis that wax-secreting Scymnus creperus Mulsant larvae are less susceptible than non-wax-secreting Coleomegilla maculata (DeGeer) larvae to S. invicta aggression. Laboratory experiments were set up using bird cherry-oat aphid Rhopalosiphum padi (L.) nymphs and adults (as prey for coccinellids) on barley leaves in arenas with either coccinellid species and with or without S. invicta workers. The presence of S. invicta reduced aphid predation by C. maculata but not Sc. creperus. The frequency of S. invicta attack was greater for C. maculata than Sc. creperus; mortality was significantly greater for C. maculata than Sc. creperus. The wax covering on Sc. creperus reduced S. invicta aggression. Unexpectedly, Sc. creperus larvae with the wax cover removed did not suffer more S. invicta attacks or increased mortality. In conclusion, the wax cover and, perhaps, the volatile or non-volatile compounds in the wax and on the integument of Sc. creperus larvae reduce S. invicta aggression. Further research could identify the wax compounds and determine their functionality as semiochemicals against S. invicta. [ABSTRACT FROM AUTHOR]

Aphis craccivora is a serious insect pest. attacks leguminous crops in Egypt. It causes harm through directly sapsucking or through indirectly viral diseases transmission. Aphid control mainly rely on the use of synthetic insecticides. Sulfoxaflor, a fourth-generation neonicotinoid, used to manage sap-sucking pests which had developed resistance to other insecticide. But, risk assessment of sulfoxaflor resistance in the cowpea aphid has not been studied before. So, the leaf-dip bioassay method was used to predict sulfoxaflor resistance, cross resistance and resistance stability in A. craccivora. Sulfoxaflor resistant strain of the cowpea aphid was obtained by selecting the field strain for 17 generations. The sulfoxaflor-selected strain (SFX- SEL strain) showed a 125.39-fold. Realized heritability (h²) of resistance was calculated to be 0.19. According to predicted rates of sulfoxaflor resistance indicated that, if h² = 0.19with is fifty percent at each generation, then a tenfold increase in LC50 would beanticipated in 12.29 generations. The obtained results showed increased levels of cross-resistance to flupyradifurone (18.16-fold),and pymetrozine (14.19-fold). Oppositely, the R-strain did not show cross-resistance to pirimicarb (3.64-fold), carbosulfan (3.5-fold), malathion (3.41-fold), dinotefuran (3.39-fold), -cyhalothrin (1.22-fold), and fipronil (1.12-fold), respectively. Fortunately, resistance to sulfoxaflor was reversed aroundcontrol strain throughout 20 generations without exposur to any insecticide. Our findings revealed the cowpea aphid's ability to evolve sulfoxaflor resistance under continual selection pressure. The retreat of sulfoxaflor makes A. craccivora compatible with techniques for managing resistance such as noncross- resistant insecticides rotation. [ABSTRACT FROM AUTHOR]

Summary: RNA interference (RNAi)‐based technologies are starting to be commercialized as a new approach for agricultural pest control. Horizontally transferred genes (HTGs), which have been transferred into insect genomes from viruses, bacteria, fungi or plants, are attractive targets for RNAi‐mediated pest control. HTGs are often unique to a specific insect family or even genus, making it unlikely that RNAi constructs targeting such genes will have negative effects on ladybugs, lacewings and other beneficial predatory insect species. In this study, we sequenced the genome of a red, tobacco‐adapted isolate of Myzus persicae (green peach aphid) and bioinformatically identified 30 HTGs. We then used plant‐mediated virus‐induced gene silencing (VIGS) to show that several HTGs of bacterial and plant origin are important for aphid growth and/or survival. Silencing the expression of fungal‐origin HTGs did not affect aphid survivorship but decreased aphid reproduction. Importantly, although there was uptake of plant‐expressed RNA by Coccinella septempunctata (seven‐spotted ladybugs) via the aphids that they consumed, we did not observe negative effects on ladybugs from aphid‐targeted VIGS constructs. To demonstrate that this approach is more broadly applicable, we also targeted five Bemisia tabaci (whitefly) HTGs using VIGS and demonstrated that knockdown of some of these genes affected whitefly survival. As functional HTGs have been identified in the genomes of numerous pest species, we propose that these HTGs should be explored further as efficient and safe targets for control of insect pests using plant‐mediated RNA interference. [ABSTRACT FROM AUTHOR]

Coccinellids are important biological control agents and aphid predators in horticultural crops around the world. Neotropical Cycloneda sanguinea, Eriopis connexa and Coleomegilla quadrifasciata octodecimpustulata, and the exotic Harmonia axyridis (all Coleoptera: Coccinellidae), are predators that mainly feed on aphids. In this work we described the abundance of these coccinellid species and their spatial and temporal cooccurrence in agroecological eggplant crop of Argentina. We also estimate the intensity and symmetry of the intraguild predation between C. quadrifasciata octodecimpustulata and the other species in laboratory experiments. Both temporal and spatial segregation was observed. H. axyridis was the strongest intraguild predator in the interaction with C. quadrifasciata octodecimpustulata, and this latter was the strongest intraguild predator in interaction with C. sanguinea and E. connexa. In this context, native coccinellid species would be vulnerable to the exotic and invasive H. axyridis; however, the lack of cooccurrence of this species with the native ones, under conditions of low density of extra-guild prey would indicate that spatial segregation could be the mechanism by which these species coexist in the eggplant crop. [ABSTRACT FROM AUTHOR]

Mass releases of two parasitoid species, Aphidius matricariae and Ephedrus cerasicola, may provide an alternative measure to pesticides to control the rosy apple aphid Dysaphis plantaginea in organic apple orchards. As an exploratory study, we tested if the presence of flower strips between apple tree rows could improve the action of three early parasitoid releases––and of other naturally present aphid enemies––on the control of aphid colonies and the number of aphids per tree. Apple trees located at various distances from parasitoid release points were monitored in plots with and without flower strips in an organic apple orchard over two years, along the season of aphid infestation (March to July). Our case study demonstrated that the presence of flowering plant mixes in the alleyways of the apple orchard reduced the presence of D. plantaginea by 33.4%, compared to plots without flower strips, at the infestation peak date. We also showed a negative effect of increasing the distance to parasitoid release points on aphid control. However, our results at the infestation peak date suggest that the presence of flower strips could marginally compensate for the detrimental effect of increasing distance to the release point, probably by improving the persistence and dispersal capacities of natural enemies. Despite high variations in aphid population dynamics between years, we conclude that combining flower strips with early parasitoid releases in apple orchards is promising for biological control of the rosy apple aphid, although the method merits to be further refined. [ABSTRACT FROM AUTHOR]

A conventional spraying mode and a fully autonomous fruit tree operation mode using a model DJ T30 unmanned aerial vehicle (UAV) were used to control aphids control on elm trees and to clarify the distribution of droplets in elm trees sprayed by an UAV. The effects of six aviation spray adjuvants on elm canopy droplet deposition and aphid control were evaluated. ImageJ software was used to analyze and measure the droplet density and deposition of water sensitive paper in two modes; this was done to calculate the droplet uniformity, depositional penetration and droplet penetration, and to verify the aphid control effect. The results showed that the droplet density increased by 79.7%-100.7% in the upper canopy and 0-394.1% in the lower canopy without adjuvants in the fully autonomous fruit tree operation mode. The upper canopy deposits increased by 65.7%-179.3%, and the lower canopy increased by 0-152.8%. When adjuvants were added, the droplet density in the upper canopy increased by 49.7-56.1% using Jiexiaofeng (JXF), and the lower canopy increased by 138.2%-177.8% using JXF, 45.8%-141.3% using Beidatong (BDT), 45.5%-92.9% using Gongbei (GB), 0-93.5% using Maisi (MS), and 0-95.2% using Manniu (MN). The deposits of the upper canopy increased by 888.1-1154.2% using JXF, 0-1298.3% using MN, 0-343.9% using BDT, 0-422.5% using GB, 0-580.3% using MS. The lower canopy increased by 746.4%-1426.0% using JXF, 226.2%-231.0% using BDT, 435.8%-644.0% using GB, 255.0%-322.4% using MS, and 249.3%-360.0% using MN. When JXF was added, the droplet uniformity, droplet penetration and depositional penetration were better than when using other adjuvants. The effects of JXF, BDT and GB in controlling aphids was significantly better than other adjuvants (p<0.05). The following control effects were observed; 94.1% with JXF, 93.1% with BDT, and 93.3% with GB after 3 d of application, and 97.9% with JXF, 95.6% with BDT, and 97.1% with GB after 7 d of application. At the same time, the application of the fully autonomous fruit tree operation mode and JXF can effectively improve the density and deposits, which will produce a superposition optimization effect. Our study focuses on the prevention and control of elm aphid infestations based on the operation mode of a UAV and aviation spray adjuvants, which can provide a baseline for the control of diseases and insect pests using UAVs in agriculture and forestry. [ABSTRACT FROM AUTHOR]

Aphidoletes aphidimyza is one of the most important natural enemies of aphids, but its efficiency in aphid control is affected by temperatures. We measured the life history parameters of A. aphidimyza by exposing its different life stages to 35°C for 3, 6, and 12 h. The results showed that the survival rate of eggs, first instar larvae, pupae, and mated males was decreased significantly with the increase of the exposure duration, whereas the survival rate of third instar larvae and adult females was not significant different before and after the exposure. The short-term high temperature stress also significantly decreased the predation of first and second instar larvae, whereas the predation of third instar larvae was not affected. In addition, the heat stress did not affect adult egg production, longevity, and offspring hatching rates, regardless of mating status. These results demonstrated that short periods of heat stress negatively influenced A. aphidimyza development, but the effect was dependent on duration and developmental stage. Therefore, in order to achieve the best predatory efficacy of gall midges against aphid pests, the heat stresses above 35°C should be avoided. [ABSTRACT FROM AUTHOR]

Facultative bacterial endosymbionts are prevalent in aphid pest species and key organisms for the rapid adaptation to changing environment conditions under agricultural management. Facultative endosymbiont interactions allow beneficial phenotypes of insect hosts, providing resistance against natural enemies, fungal infections as well as enhanced resistance to thermal conditions, among others. These interactions have been highlighted as important modulators in the evolution of aphid defenses, being a key aspect for the invasive potential of aphids as pests. In this study, we have examined the bacterial community diversity associated to the pea aphid Acyrthosiphon pisum on alfalfa (Medicago sativa L.) crops in Central Chile by determining the presence and abundance of the seven most common facultative endosymbionts reported for aphid species, including: Hamiltonella defensa, Regiella insecticola, Serratia symbiotica, Spiroplasma sp., Rickettsia sp., Rickettsiella viridis and Fukatsuia symbiotica (or pea aphid X-type symbiont' PAXS), using a PCR-based approach across species-specific primers, in 16 alfalfa fields during the Chilean spring in the Maule Region. We reported six of the seven endosymbiont species studied, observing a high frequency of infected aphids being the endosymbiont H. defensa, the most predominant among the aphid populations in the different alfalfa fields studied. As H. defensa has been extensively studied in its defensive role to parasitoids, we discuss implications for biological control of this aphid pests. We also discuss the absence of a relevant defensive endosymbiont such as F. symbiotica in the Chilean pea aphid populations and potential implications for the success of the pea aphid biological control program. [ABSTRACT FROM AUTHOR]

The study dealt with methods of controlling aphids on some grassy field crops in Nepal. The aphids are considered a dangerous sucking piercing insect because they feed on plant sap and attack all parts of the plant and cause damage to it also transmit different viruses. The insects' spreads in both Egypt and Nepal, where the climatic conditions are similar in both countries, which prompted farmers to use multiple methods to control this insect because of the special importance of the grass field crops and where a large percentage of the population depends on them. There are many ways to control aphids, biologically, chemically, and others. One of the most important methods of combating this insect is integrated pest management (IPM). This controlling strategy depends on the rational use of both physical and mechanical control, chemical and biological control, and organizational and legislative control in a way that achieves the goal of its use and maintains the ecological balance. To accomplish this, it is necessary to persuade farmers to use alternative methods to combat natural enemies, particularly aphids, in addition to planting new pest- and disease-resistant plant varieties, exploiting the available natural resources and exploiting environmental factors to eliminate pests, as well as raising their awareness of the effective time and appropriate time to spray pesticides in the proper way, as well as the precautions to be taken into account when spraying and information related to chemical control, as well as their skill in using other control methods and evaluating these uses in control, especially aphids. [ABSTRACT FROM AUTHOR]

Simple Summary: When there are multiple natural enemies in the same ecosystem, intraguild predation between natural enemies will affect the population dynamics of target organisms and the effectiveness of biological control. It is necessary to study this relationship in depth to enhance the function of biological control. Hippodamia variegata (Goeze) and parasitoids are two types of dominant natural enemies of the cotton aphid Aphis gossypii Glover in Xinjiang, China. Among them, the ladybeetle preys on common aphids as well as parasitoids. This study measured the feeding choices of H. variegata towards mummies with different densities of A. gossypii. Meanwhile, investigation and sampling in the cotton field were conducted from 2017 to 2019. The predation of H. variegata individuals on aphids and mummies was detected using diagnostic PCR. The results showed that H. variegata had no obvious feeding preference towards live aphids and mummies, and preferred denser prey. The molecular detection results show that A. gossypii was the main prey source and medium of consumption of parasitoids for the ladybeetle. H. variegata had strong trophic links to both parasitoids and aphids. The above information is crucial for evaluating the pest control ability of H. variegata more comprehensively and strengthening the strategies for the biological control of aphids. Intraguild predation among arthropod predators in agricultural ecosystems may have a negative impact on biological control. At present, there are few direct reports on trophic relationships among participants of predation in field groups. In this study, we measured the feeding choices of Hippodamia variegata (Goeze) towards mummies with different densities of Aphis gossypii Glover. The dynamics of the occurrence of mummies in the cotton field were investigated over 2017–2019. Singleplex PCR and multiplex PCR were used to detect the predation of 2090 H. variegata individuals on aphids and mummies in Xinjiang cotton field, which revealed the intraguild predation frequency between H. variegata and various parasitoids. There was no obvious feeding preference of H. variegata towards live aphids or mummies, which mainly depended on the relative density of prey. Among the four species of aphids detected in H. variegata, A. gossypii had a high detection rate and was the main prey source of the ladybeetle in the cotton filed. Mostly, ladybeetles consumed parasitoids through mummies, with 6.39% directly feeding on adult parasitoids. H. variegata had strong trophic links to both parasitoids and aphids. We established a food web of aphids–primary parasitoids–hyperparasitoids–H. variegata, which can be used to evaluate the pest control ability of H. variegata from a new perspective. [ABSTRACT FROM AUTHOR]

Simple Summary: Maximizing the combination of biological control by natural enemies and plant resistance is a key strategy for controlling aphids in various crop systems. In our study, some alfalfa cultivars were found to have resistance to the pea aphid, Acyrthosiphon pisum, a dominant pest in alfalfa fields in northwestern China. In addition, natural enemies were able to significantly suppress this aphid, regardless of the resistance level of the nine cultivars tested. Moreover, the biological control efficacies of predators, parasitoids, and mixed populations of natural enemies were 85%, 42%, and 88%, respectively. Conservation of natural enemies in the field is an ecologically sound and efficient approach to the management of the pea aphid in alfalfa crops. The pea aphid, Acyrthosiphon pisum Harris, is a major pest of alfalfa in northwestern China. However, the roles of different groups of natural enemies in combination with aphid-resistant cultivars in the suppression of the pea aphid have not been clarified under field conditions. In this study, we used experimental cages to better understand the top-down (natural enemies) and bottom-up (nine alfalfa cultivars) biological processes, as well as the individual roles of the two processes, in the control of the pea aphid. There was a significant difference in resistance among cultivar classes revealed when natural enemies were excluded. The functional contribution of top-down suppression was higher than the bottom-up process, with natural enemies significantly suppressing aphid populations, regardless of the resistance level of different alfalfa cultivars. The mean biological efficacies of predators, parasitoids, and mixed populations of natural enemies were 85%, 42%, and 88%, respectively. Overall, our study indicated that natural enemies play a critical role in suppressing aphid populations, especially in the summer, whereas cultivar resistance did not combine effectively with natural enemies to inhibit the growth of aphids. Conservation biological control (CBC) can be implemented in the alfalfa production regions in northwestern China to reduce the overreliance on insecticides for the control of pests and mitigate their harmful effects on humans, ecosystems, and biodiversity. [ABSTRACT FROM AUTHOR]

Aphids are a major group of crop pests, which directly feed on phloem and indirectly transmit plant virus. The entomopathogenic fungi are essential members of green pest control strategies, and insecticidal RNAi is considered as a new generation of biopesticides. However, the effects of combining entomopathogenic fungus and RNAi-based biopesticides for aphid control are unknown. Here, the responsive genes of Acyrthosiphon pisum were screened from the transcriptomes upon spraying of Beauveria bassiana Bb07 strain (hereafter referred to Bb07). Subsequently, six candidate genes, Ap4714, Ap15782, Ap20844, Ap14741, Ap15105 and Ap16968, were targeted by spray-based RNAi, which produced a range of 20.0, 58.0, 44.0, 27.0, 52.0 and 24.0% gene silencing, respectively. Silencing of single-target (Ap4714, Ap15782, and Ap20844) resulted in increased virulence of Bb07 to Ac. pisum. Importantly, the mortality was increased to 82.1, 76.7, and 60.7% within 7 days to Ac. pisum when double-targets (Ap4714 + Ap15782, Ap4714 + Ap20844 and Ap15782 + Ap20844) were silenced in together with application of Bb07, respectively. This high mortality was also observed in Myzus persicae and Aphis citricidus by co-spray of the combination of dsAp4714 + dsAp15782 together with Bb07. In together, this study demonstrates the potential of a combination of RNAi- and entomopathogenic fungus-based technologies to control aphids, thereby reducing application of chemical pesticides. [ABSTRACT FROM AUTHOR]

Biopesticides based on RNA interference (RNAi) act in a sequence-dependent manner. Homology between target genes in insect pests and orthologs in non-target beneficial insects should therefore be investigated during the design of double-stranded RNA (dsRNA) constructs and by experimental testing to evaluate off-target effects. Here we investigated potential off-target effects against the ladybeetle Propylea japonica (Thunberg) (Coleoptera: Coccinellidae), an important biological control agent, in the context of RNAi-based aphid control. First, we sequenced the full-length P. japonica transcriptome and predicted potential off-target sites at the whole-transcriptome level in the pea aphid Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae) as queries. We found off-target sites in almost every P. japonica genes. Second, we found that first-instar P. japonica larvae were more sensitive to dsRNA exposure than other developmental stages by comparing the silencing efficiency of three indicator genes (IAP, V-ATP and CHMP-4b). The expression of core siRNA pathway genes after dsRNA treatment confirmed that the response to dsRNA was more robust in first-instar larvae than adults. Finally, we used the A. pisum alpha-actinin gene as a case study to design dsRNA fragments with different degrees of efficacy against P. japonica, confirming that the safety of RNAi approaches can be enhanced by rational dsRNA design. [ABSTRACT FROM AUTHOR]

Aphids form a tight and mutually beneficial symbiosis with their primary symbiont Buchnera aphidicola, which plays a prominent role in aphid nutrition metabolism. Here, we sequenced the genome of B. aphidicola from the wheat aphid Sitobion miscanthi and performed KEGG analysis of amino acid synthesis pathways based on our previously published S. miscanthi genome. The genome of B. aphidicola from S. miscanthi contained almost all genes of the valine (Val), leucine (Leu) and isoleucine (Ile) synthesis pathways; however, it lacked a branched-chain amino acid aminotransferase (ilvE) required in the pathways, but this gene was present in the S. miscanthi genome. Sequence analysis showed that the ilvE gene was highly conserved in aphids. ilvE was highly expressed in the 3rd and 4th instars of S. miscanthi and showed higher expression in the bacteriocyte than in other parts. After RNAi-mediated ilvE knockdown, the result showed a significant mortality and body weight losses. Meanwhile, the B. aphidicola relative abundance and the Val, Leu and Ile production decreased significantly after ilvE gene interference. These results indicate that ilvE is a “bridge” gene in the aphid genome, linking the metabolic relay between aphids and B. aphidicola and significantly affecting the vital life parameters of aphids, potentially by affecting Val, Ile and Leu production. Our study may provide a future direction for using key junctions of the metabolic relay between insects and endosymbionts as RNAi target loci to develop new strategies for agricultural pest control. [ABSTRACT FROM AUTHOR]

The chemical insecticide flonicamid is widely used to control aphids on crops. Differences among crops make the universality of detection methods a particularly important consideration. The aim of this study was to establish a universal, sensitive, accurate and efficient method for the determination of flonicamid residues in peach, cucumber, cabbage and cotton. QuEChERS pretreatment was combined with ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). A satisfactory recovery rate of 84.3–99.3% was achieved at three spiking levels, and the relative standard deviation (RSD) was 0.41–5.95%. The limit of quantification (LOQ) of flonicamid in the four matrices was 0.01 mg/kg. The residue and dissipation kinetics of flonicamid in four types of crops in various locations were determined by using the optimized method. The results showed that flonicamid had a high dissipation rate in the four different types of crops and a half-life in the different matrices and locations of 2.28–9.74 days. The terminal residue of flonicamid was lower than the maximum residue limit (MRL). The risk quotient (RQ) of flonicamid was 4.4%, which is significantly lower than 100%. This result shows that the dietary risk presented by using flonicamid at the maximum recommended dose is low and acceptable. The comprehensive long-term dietary risk assessment of flonicamid performed in this study provides a reference for the protection of consumer health and safe insecticide use. [ABSTRACT FROM AUTHOR]

Background: Scaeva pyrastri (L.) (Diptera: Syrphidae) is a large-size Palaearctic region syrphid fly. The larval stage of S. pyrastri is aphidophagous in nature, while the adults are efficient pollinators of various crops. Therefore, this study was carried out to investigate the predation efficacy, biology and population growth parameters of S. pyrastri on the cabbage aphid, Brevicoryne brassicae (L.) (Hemiptera: Aphididae) as prey using age–stage-specific two-sex fertility table. Results: The results showed that the mean total larval development duration was 8.31 days and the pre-adult stage was 19.82 ± 0.25 days long. In the adult stage, the mean longevity of female (18.57 ± 0.37 days) was longer than that of the male (15.50 ± 0.17 days). The adult pre-ovipositional, ovipositional and post-ovipositional periods were 4.25 ± 0.25, 8.50 ± 0.46 and 3.25 ± 0.31 days, respectively, and the mean female's fecundity was 37.75 ± 1.16 eggs per female. The two-sex fertility table indicated that the age-specific fecundity (mx) increased gradually peaking at the 27th day of pivotal age (2.71 eggs per day) and decreased thereafter. The life expectancy of female was observed on the 18th (20.25 days) and 19th day (16.44 days) in the female and male flies, respectively. The female attained the maximum reproductive value (vxj) on the 25th day, which was 26.05 eggs needed to produce one individual. The population growth parameters indicated that the population had a net reproduction rate of 15.10 ± 4.19 offspring per individual and a true generation time of 28.86 ± 0.28 days. The intrinsic rate of increase was greater than zero (0.093 ± 0.011) and the finite rate of increase (λ) was greater than one (1.098 ± 0.012), which indicated that B. brassicae was the suitable prey for S. pyrastri. The values related to the number of aphids consumed by the larvae were: a net predation rate (Co) of 377.06 ± 26.54 nymphs and finite predation rate (ω) of 19.58 ± 0.78. Conclusions: Scaeva pyrastri had a considerable predatory potential and fitted well for the biological control of aphids, especially B. brassicae. However the field potential is still unknown; thus, this study will be helpful in determining the field efficacy of S. pyrastri against B. brassicae. [ABSTRACT FROM AUTHOR]

Because our civilization has relied on pesticides to fight weeds, insects, and diseases since antiquity, the use of these chemicals has become natural and exclusive. Unfortunately, the use of pesticides has progressively had alarming effects on water quality, biodiversity, and human health. This paper proposes to improve farming practices by replacing pesticides with a laser-based robotic approach. This study focused on the neutralization of aphids, as they are among the most harmful pests for crops and complex to control. With the help of deep learning, we developed a mobile robot that spans crop rows, locates aphids, and neutralizes them with laser beams. We have built a prototype with the sole purpose of validating the localization-neutralization loop on a single seedling row. The experiments performed in our laboratory demonstrate the feasibility of detecting different lines of aphids (50% detected at 3 cm/s) and of neutralizing them (90% mortality) without impacting the growth of their host plants. The results are encouraging since aphids are one of the most challenging crop pests to eradicate. However, enhancements in detection and mainly in targeting are necessary to be useful in a real farming context. Moreover, robustness regarding field conditions should be evaluated. [ABSTRACT FROM AUTHOR]