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Showing papers on "Aphid published in 2022"


Proceedings ArticleDOI
28 Apr 2022
TL;DR: In this paper , a Mask RCNN model was used to identify the location of each aphid in individual leaves automatically with the help of a Canon camera, a total of 6500 wheat images have been captured in the Punjab region with temperature 21-24° temperature.
Abstract: Wheat is one of the most common cereal crops in India. Aphids cause extensive damage to the whole wheat plant and lead to high yields loss. The aphid is transmitted on the summer day. Once the aphid is transmitted over the leave, the whole plant leave is damaged. Due to this, got damage whete plant and it also reduce the quality of wheat grain. Due to which the it is necessary to identify each aphid on wheat leaves. Only manual process is there to identify each aphid on wheat leave. Manually identification is a time-consuming and high laborious process. Therefore, the identification of wheat aphids through the Mask RCNN model can easily identify the location of each aphid in individual leave automatically. With the help of a Canon camera, a total of 6500 wheat images have been captured in the Punjab region with temperature 21–24° temperature. The Labelme software is used for the annotation of wheat leaves and wheat aphid. A total of 2300 and 1000 images have been randomly selected for training and testing purposes. The Mask scoring RCNN model is having a network capacity for learning the quality of predicted instance masks. Among all 1221 wheat leaves, a total number of 1021 wheat aphids have been found. The manually annotated ROI was compared to mask scoring ROI for wheat aphid identification and localization. Thus, the Mask scoring RCNN model has been achieved a high F1-score (96.66%) for wheat aphid detection in single wheat leave.

25 citations


Journal ArticleDOI
TL;DR: In this article , the larvae and adults of Eupeodes corollae detect and are attracted to EBF and found a neuron housed in type III basiconic sensilla of adult antenna responding to it.

21 citations


Journal ArticleDOI
TL;DR: In this article , the authors used correlation and multivariate regression modeling to detect relationships with insects at different spatial scales and found that more complex landscape configuration, particularly the amount of habitat edges, was associated with increased aphid and natural enemy abundance.
Abstract: Abstract Landscapes with more complex composition and configuration are generally expected to enhance natural enemy densities and pest suppression. To evaluate this hypothesis for an invasive aphid pest of sorghum, Melanaphis sorghi Theobald (Hemiptera: Aphididae), sampling in sorghum fields for aphids and natural enemies was conducted over two years in a southern U.S. coastal production region. Landscape composition and configuration of crop and noncrop elements were assessed using correlation and multivariate regression modeling to detect relationships with insects at different spatial scales. Significant models found more complex landscape configuration, particularly the amount of habitat edges, was associated with increased aphid and natural enemy abundance. Composition associated with noncrop habitats had the opposite effect. Numerical response of natural enemies was taxa dependent, with parasitism lower as landscape complexity increased, while predator numerical response was not affected by landscape complexity. These results indicate landscape complexity may increase both aphid and natural enemy abundance, but with decreasing parasitism and little association with predator numerical response. These relationships are likely contingent on overall environmental suitability to aphid population increase as results were less evident in the second year when average aphid abundance regularly exceeded the economic threshold. This study supports the importance of configuration, especially habitat borders, as a critical metric for determining pest-natural enemy dynamics within a large-scale cereal agroecosystem.

17 citations


Journal ArticleDOI
TL;DR: Interestingly, it was found that A. gossypii collected from cotton plants showed higher tolerance to afidopyropen compared with individuals collected from the other host plants.

14 citations


Journal ArticleDOI
TL;DR: In this article , the authors evaluated the susceptibility baseline of field populations of A. gossypii to the novel pyropene insecticide afidopyropen and found that the susceptibility of these populations to this newly commercialized insecticide is important for ensuring its continued efficacy.

13 citations


Journal ArticleDOI
TL;DR: In this article , a green peach aphid (GPA, Myzus persicae)-dodder (Cuscuta australis)-cucumber (Cucumis sativus) tritrophic system was constructed by infesting GPAs on cucumber hosts.

12 citations


Journal ArticleDOI
TL;DR: Turnip mosaic virus (TuMV) is an economically important virus infecting a broad range of arable and vegetable crops and many wild plant species as discussed by the authors , it is also of particular scientific interest as it has the broadest host range of any of the potyviruses, infects dicotyledonous and monocotyleronous plants, is transmitted by many (>89) aphid species and is the best adapted potyvirus to Arabidopsis.
Abstract: Turnip mosaic virus (TuMV) is an economically important virus infecting a broad range of arable and vegetable crops and many wild plant species. It is also of particular scientific interest as it has the broadest host range of any of the potyviruses, infects dicotyledonous and monocotyledonous plants, is transmitted by many (>89) aphid species and is the best adapted potyvirus to Arabidopsis. For these reasons it has been particularly well studied from many angles and is being exploited for biotechnological purposes. This review aims to consolidate the most recent advances in research on TuMV and will form the basis of an updated version on the Association of Applied Biologists (AAB) Description of Plant Viruses for TuMV.

12 citations



Journal ArticleDOI
TL;DR: This review will cover the current state of knowledge about when, where, and how ROS accumulate in response to aphids, which salivary effectors modify ROS levels in plants, andHow microbial associates influence ROS induction by aphids.
Abstract: Reactive oxygen species (ROS) such as hydrogen peroxide and superoxide are produced in plants in response to many biotic and abiotic stressors, and they can enhance stress adaptation in certain circumstances or mediate symptom development in others. The roles of ROS in plant-pathogen interactions have been extensively studied, but far less is known about their involvement in plant-insect interactions. A growing body of evidence, however, indicates that ROS accumulate in response to aphids, an economically damaging group of phloem-feeding insects. This review will cover the current state of knowledge about when, where, and how ROS accumulate in response to aphids, which salivary effectors modify ROS levels in plants, and how microbial associates influence ROS induction by aphids. We will also explore the potential adaptive significance of intra- and extracellular oxidative responses to aphid infestation in compatible and incompatible interactions and highlight knowledge gaps that deserve further exploration.

12 citations


Journal ArticleDOI
TL;DR: In this article , the green peach aphid, Myzus persicae, has been found to have low-level resistance to sulfoxaflor in Australia and uncover two novel mechanisms conferring resistance to this compound.

11 citations


Journal ArticleDOI
TL;DR: In this article , a review of recent advances and challenges related to the control of grain aphids in agricultural production is presented, which shows that the integration of the large-scale cultivation of aphid-resistant wheat cultivars with agricultural and/or other management practices will be the most prevalent and economically important management strategy for wheat aphid control.
Abstract: Cereal plants in natural ecological systems are often either sequentially or simultaneously attacked by different species of aphids, which significantly decreases the quality and quantity of harvested grain. The severity of the damage is potentially aggravated by microbes associated with the aphids or the coexistence of other fungal pathogens. Although chemical control and the use of cultivars with single-gene-based antibiosis resistance could effectively suppress grain aphid populations, this method has accelerated the development of insecticide resistance and resulted in pest resurgence. Therefore, it is important that effective and environmentally friendly pest management measures to control the damage done by grain aphids to cereals in agricultural ecosystems be developed and promoted. In recent decades, extensive studies have typically focused on further understanding the relationship between crops and aphids, which has greatly contributed to the establishment of sustainable pest management approaches. This review discusses recent advances and challenges related to the control of grain aphids in agricultural production. Current knowledge and ongoing research show that the integration of the large-scale cultivation of aphid-resistant wheat cultivars with agricultural and/or other management practices will be the most prevalent and economically important management strategy for wheat aphid control.

Journal ArticleDOI
14 Jan 2022-Toxins
TL;DR: This study examines the antimicrobial, cytotoxic, and insecticidal activity of full-length Checacin1, a major component of the Chelifer cancroides venom, and three truncated forms of this peptide, and describes for the first time pharmacological effects of AMPs discovered in pseudoscorpion venom.
Abstract: Linear cationic venom peptides are antimicrobial peptides (AMPs) that exert their effects by damaging cell membranes. These peptides can be highly specific, and for some, a significant therapeutic value was proposed, in particular for treatment of bacterial infections. A prolific source of novel AMPs are arthropod venoms, especially those of hitherto neglected groups such as pseudoscorpions. In this study, we describe for the first time pharmacological effects of AMPs discovered in pseudoscorpion venom. We examined the antimicrobial, cytotoxic, and insecticidal activity of full-length Checacin1, a major component of the Chelifer cancroides venom, and three truncated forms of this peptide. The antimicrobial tests revealed a potent inhibitory activity of Checacin1 against several bacteria and fungi, including methicillin resistant Staphylococcus aureus (MRSA) and even Gram-negative pathogens. All peptides reduced survival rates of aphids, with Checacin1 and the C-terminally truncated Checacin11-21 exhibiting effects comparable to Spinosad, a commercially used pesticide. Cytotoxic effects on mammalian cells were observed mainly for the full-length Checacin1. All tested peptides might be potential candidates for developing lead structures for aphid pest treatment. However, as these peptides were not yet tested on other insects, aphid specificity has not been proven. The N- and C-terminal fragments of Checacin1 are less potent against aphids but exhibit no cytotoxicity on mammalian cells at the tested concentration of 100 µM.

Journal ArticleDOI
01 Sep 2022
TL;DR: In this paper , the role of jasmonic acid (JA) in defending against sugarcane aphid (SCA) attack on sorghum production was investigated.
Abstract: The precursors and derivatives of jasmonic acid (JA) contribute to plant protective immunity to insect attack. However, the role of JA in sorghum ( Sorghum bicolor) defense against sugarcane aphid (SCA) ( Melanaphis sacchari), which is considered a major threat to sorghum production, remains elusive. Sorghum SC265, previously identified as a SCA-resistant genotype among the sorghum nested association mapping founder lines, transiently increased JA at early stages of aphid feeding and deterred aphid settling. Monitoring of aphid feeding behavior using electropenetrography, a technique to unveil feeding process of piercing-sucking insects, revealed that SC265 plants restricted SCA feeding from the phloem sap. However, exogenous application of JA attenuated the resistant phenotype and promoted improved aphid feeding and colonization on SC265 plants. This was further confirmed with sorghum JA-deficient plants, in which JA deficiency promoted aphid settling, however, it also reduced aphid feeding from the phloem sap and curtailed SCA population. Exogenous application of JA caused enhanced feeding and aphid proliferation on JA-deficient plants, suggesting that JA promotes aphid growth and development. SCA feeding on JA-deficient plants altered the sugar metabolism and enhanced the levels of fructose and trehalose compared with wild-type plants. Furthermore, aphid artificial diet containing fructose and trehalose curtailed aphid growth and reproduction. Our findings underscore a previously unknown dichotomous role of JA, which may have opposing effects by deterring aphid settling during the early stage and enhancing aphid proliferative capacity during later stages of aphid colonization on sorghum plants. [Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Journal ArticleDOI
TL;DR: It is found that S. symbiotica was present in non-aphid species and in host plants, and that its prevalence was higher when associated aphid colonies were infected, providing a new picture of the pervasiveness of an insect symbiont in nature.

Journal ArticleDOI
TL;DR: The salivary effector Sg2204 of S. graminum involved in promoting host susceptibility by suppressing wheat defence, which can also be regarded as a promising RNAi target for aphid control is characterized.
Abstract: Summary Aphids secrete diverse repertoires of salivary effectors into host plant cells to promote infestation by modulating plant defence. The greenbug Schizaphis graminum is an important cereal aphid worldwide. However, the secreted effectors of S. graminum are still uncharacterized. Here, 76 salivary proteins were identified from the watery saliva of S. graminum using transcriptome and proteome analyses. Among them, a putative salivary effector Sg2204 was significantly up‐regulated during aphid feeding stages, and transient overexpression of Sg2204 in Nicotiana benthamiana inhibited cell death induced by BAX or INF1. Delivering Sg2204 into wheat via the type III secretion system of Pseudomonas fluorescens EtAnH suppressed pattern‐triggered immunity (PTI)‐associated callose deposition. The transcript levels of jasmonic acid (JA)‐ and salicylic acid (SA)‐associated defence genes of wheat were significantly down‐regulated, and the contents of both JA and SA were also significantly decreased after delivery of Sg2204 into wheat leaves. Additionally, feeding on wheat expressing Sg2204 significantly increased the weight and fecundity of S. graminum and promoted aphid phloem feeding. Sg2204 was efficiently silenced via spray‐based application of the nanocarrier‐mediated transdermal dsRNA delivery system. Moreover, Sg2204‐silenced aphids induced a stronger wheat defence response and resulted in negative impacts on aphid feeding behaviour, survival and fecundity. Silencing of Sg2204 homologues from four aphid species using nanocarrier‐delivered dsRNA also significantly reduced aphid performance on host plants. Thus, our study characterized the salivary effector Sg2204 of S. graminum involved in promoting host susceptibility by suppressing wheat defence, which can also be regarded as a promising RNAi target for aphid control.

Journal ArticleDOI
TL;DR: In this paper , aniseed essential oil nanoemulsions were prepared using a laboratory dispersing machine at a high-speed regime (10 min, 7940 revs/min, 15 °C) using Tween80 as a surfactant at a 1:2 ratio.

Journal ArticleDOI
TL;DR: In this article , a multi-branch convolutional neural network (Mb-CNN) with density map for aphid counting is developed, which achieves the performance of 10.22 Mean Absolute Error (MAE) and 12.24 Mean Squared Error (MSE) in the counting of aphids.

Journal ArticleDOI
TL;DR: In this article , the authors used mass spectrometry to identify 155 proteins from the wheat aphid, Sitobion miscanthi, among which 44 proteins were derived from the primary symbiont, Buchnera aphidicola.
Abstract: Salivary proteins secreted by aphids during feeding play an important role in regulating the plant defense response. We used mass spectrometry to identify 155 proteins from the wheat aphid, Sitobion miscanthi, among which 44 proteins were derived from the primary symbiont, Buchnera aphidicola. GroES, which is a highly abundant molecular chaperone that binds to GroEL, was detected in saliva. In vitro injection of purified GroES protein and overexpression of GroES in wheat leaves verified that GroES induced hydrogen peroxide accumulation and callose deposition in wheat and further activated the plant salic acid and jasmonic acid defense pathways. Our findings indicate that plants may have evolved new strategies to detect aphid attack and trigger defense responses by recognizing proteins derived from B. aphidicola, which is present in almost all aphid species.

Journal ArticleDOI
TL;DR: This study investigates the evolution of resistance to a new plant protection product, spirotetramat, following reported chemical control failures of Myzus persicae from Australia and demonstrates that resistance is associated with the previously reported mutation, A2226V in the target-site of spiroteramat, acetyl-CoA carboxylase.
Abstract: Abstract BACKGROUND Chemicals are widely used to protect field crops against aphid pests and aphid‐borne viral diseases. One such species is Myzus persicae (Sulzer), a global pest that attacks a broad array of agricultural crops and transmits many economically damaging plant viruses. This species has evolved resistance to a large number of insecticide compounds as a result of widespread and repeated chemical use in many parts of the world. In this study, we investigated the evolution of resistance to a new plant protection product, spirotetramat, following reported chemical control failures. RESULTS Our study provides clear phenotypic and genotypic evidence of spirotetramat resistance in populations of M. persicae from Australia. We show there is cross‐resistance to other insecticides within the same chemical group, namely spiromesifen and spirodiclofen. We also demonstrate that resistance is associated with the previously reported mutation, A2226V in the target site of spirotetramat, acetyl‐CoA carboxylase. Our genetic analysis found all resistant M. persicae populations belong to the same multi‐locus clonal type and carry the A2226V mutation, which appears to be inherited as a dominant trait in this species. CONCLUSION Our findings provide new insight into the resistance conferred by A2226V and have implications for the control of M. persicae in Australia and worldwide. A diagnostic assay developed in this study should serve as a valuable tool for future resistance monitoring and to support the implementation of pest management strategies. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Journal ArticleDOI
01 Mar 2022-Viruses
TL;DR: Results indicate that wild radish could serve as a reservoir host for CCYV in the USA and other parts of the world where similar conditions exist and whitefly bioassays revealed that wild Radish is an acceptable feeding and reproductive host plant.
Abstract: Cucurbit chlorotic yellows virus (CCYV) belongs to the genus Crinivirus and is part of a complex of whitefly-transmitted viruses that cause yellowing disease in cucurbits. In the southeastern USA, heavy incidences of CCYV have been observed on all cucurbits grown in the fall. CCYV was detected from wild radish (Raphanus raphanistrum L.), a common weed that grows in the southeastern USA by high-throughput sequencing as well as RT-PCR. CCYV sequence from wild radish was 99.90% and 99.95%, identical to RNA 1 and RNA 2 of cucurbit isolates of CCYV from the region. Transmission assays using whiteflies demonstrated that wild radish is a good host for CCYV. Whiteflies were also able to acquire CCYV from wild radish and transmit the virus to cucurbit hosts, which developed typical symptoms associated with CCYV. Using quantitative PCR, the titer of CCYV in wild radish was also estimated to be on par with that of cucurbit hosts of the virus. Whitefly bioassays revealed that wild radish is an acceptable feeding and reproductive host plant. These results indicate that wild radish could serve as a reservoir host for CCYV in the USA and other parts of the world where similar conditions exist.

Journal ArticleDOI
TL;DR: Salivary effector Sm9723 is involved in suppressing plant immunity and is essential in enabling aphid virulence, which could be applied as potential target gene for RNAi-mediated pest control of S. miscanthi.
Abstract: Aphid salivary effectors play important roles in modulating plant defense responses. The grain aphid Sitobion miscanthi is one of the most economically important cereal aphids worldwide. However, little information is available on the identification and functional analysis of salivary effectors of S. miscanthi. In this study, a candidate salivary effector Sm9723 was identified, which was specifically expressed in aphid salivary glands and highly induced during the aphid feeding phase. Transient overexpression of Sm9723 in Nicotiana benthamiana suppressed BAX and INF1-induced cell death. Further, Sm9723 overexpression inhibited N. benthamiana defense responses by reducing pattern-triggered immunity associated callose deposition and expression levels of jasmonic and salicylic acid-associated defense genes. In addition, the salivary effector Sm9723 of S. miscanthi was effectively silenced through nanocarrier-mediated dsRNA delivery system. After silencing Sm9723, fecundity and survival of S. miscanthi decreased significantly, and the aphid feeding behavior was also negatively affected. These results suggest salivary effector Sm9723 is involved in suppressing plant immunity and is essential in enabling aphid virulence, which could be applied as potential target gene for RNAi-mediated pest control of S. miscanthi.

Journal ArticleDOI
TL;DR: In this article , the response of three wild potato (Solanum stoloniferum Schltdl) accessions and a cultivated potato to aphid (Myzus persicae Sulzer) herbivory was investigated.
Abstract: Abstract BACKGROUND Plant resistance to insects can be reduced by crop domestication which means their wild ancestors could provide novel sources of resistance. Thus, crossing wild ancestors with domesticated crops can potentially enhance their resistance against insects. However, a prerequisite for this is identification of sources of resistance. Here, we investigated the response of three wild potato (Solanum stoloniferum Schltdl.) accessions and cultivated potato (Solanum tuberosum) to aphid (Myzus persicae Sulzer) herbivory. RESULTS Results revealed that there was a significant reduction in aphid survival and reproduction on wild potato accessions (CGN18333, CGN22718, CGN23072) compared to cultivated (Desiree) potato plants. A similar trend was observed in olfactometer bioassay; the wild accessions had a repellent effect on adult aphids. In contrast, among the tested wild potato accessions, the parasitoid Diaeretiella rapae (M'Intosh) was significantly attracted to volatiles from CGN18333. Volatile analysis showed that wild accessions emitted significantly more volatiles compared to cultivated potato. Principal component analysis (PCA) of volatile data revealed that the volatile profiles of wild and cultivated potato are dissimilar. β‐Bisabolene, (E)‐β‐farnesene, trans‐α‐bergamotene, d‐limonene, (E,E)‐4,8,12‐trimethyl‐1,3,7,11‐tridecatetraene (TMTT), and p‐cymen‐7‐ol were the main volatiles contributing to the emitted blends, suggesting possible involvement in the behavioural response of both M. persicae and D. rapae. CONCLUSION Our findings show that the tested wild accessions have the potential to be used to breed aphid‐resistant potatoes. This opens new opportunities to reduce the aphid damage and to enhance the recruitment of natural enemies. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Journal ArticleDOI
TL;DR: In this paper , two derivatives of distyrylpyridine-2-thione, 2-cyano-4,6-distylpyridin-2,yl)thio-acetamide (2) and 3-amino-N-(4-nitrophenyl)-4, 6-distrylthieno[2,3-b]pyridine -2-carboxamide (3) were synthesized from distrylpyl-2 thione.
Abstract: In examining for unique insecticidal agents, two derivatives namely, 2-((3-cyano-4,6-distyrylpyridin-2-yl)thio)-N-(4-nitrophenyl)acetamide (2) and 3-amino-N-(4-nitrophenyl)-4,6-distyrylthieno[2,3-b]pyridine-2-carboxamide (3) were synthesized from distyrylpyridine-2-thione (1). The new compounds were structurally clarified by spectral and elemental analysis data. The insecticidal activity of these compounds were carried out against cowpea aphid, Aphis craccivora Koch. It is demonstrated that the compounds 2 and 3 have noteworthy insecticidal activity against nymphs of cowpea aphid with LC50 values of 0.025-0.027 ppm and 0.005-0.006 ppm after 24 h and 48 h of treatment, respectively. Also, the compounds 2 and 3 have noteworthy insecticidal activity against adults of cowpea aphid with LC50 values of 0.112-0.129 ppm and 0.014-0.015 ppm after 24 h and 48 h of treatment, respectively, that were comparable to that of the control acetamiprid.


Journal ArticleDOI
TL;DR: In this paper , the potential of two predatory syrphids, Eupeodes corollae and Sphaerophoria rueppellii, for delivering concurrent pollination and biological control of Chaetospihon fragaefolii in greenhouse strawberries was assessed.
Abstract: BACKGROUND Predatory syrphids are an important functional group due to their potential for providing multiple ecosystem services. Adults feed on nectar and pollen and can be effective pollinators, while larvae are voracious predators that can reduce aphid pressure. Still, little research has addressed their potential dual function in agroecosystems. In this study, we assessed the potential of two predatory hoverflies, Eupeodes corollae and Sphaerophoria rueppellii, for delivering concurrent pollination and biological control of Chaetospihon fragaefolii in greenhouse strawberries. RESULTS Both hoverfly species effectively pollinated strawberry flowers of two different varieties ('Elsanta' and 'Sonsation'), resulting in an increase in high quality marketable fruits, a reduction of fruit deformities, and higher number of seeds per fruit compared to pollinator-excluded fruits. S. ruepellii had a significantly longer flower handling time than E. corollae, which translated to a more efficient pollination expressed as higher seed numbers per fruit after a single flower visit. By contrast, flowers that were open to multiple visits were more effectively pollinated by E. corollae, suggesting that E. corollae is potentially a better cross-pollinator than S. rueppellii. In addition, both hoverfly species suppressed aphid populations in strawberry (var. 'Sonata'), with S. rueppellii and E. corollae reducing aphid populations by 49% and 62%, respectively. CONCLUSION Predatory syrphids can concurrently contribute to pollination and biological control in strawberry in a greenhouse setting. This article is protected by copyright. All rights reserved.

Journal ArticleDOI
TL;DR: In this paper , the role of chemodiversity in plant-aphid interactions was investigated using the Asteraceae Tanacetum vulgare, whose individuals differ pronouncedly in the composition of leaf terpenoids, forming distinct chemotypes.
Abstract: Some plant species express an extraordinarily high intraspecific diversity in phytochemicals (= chemodiversity). As discussed for biodiversity, higher chemodiversity may provide better protection against environmental stress, including herbivory. However, little is known about whether the resistance of a plant individual towards herbivores is mostly governed by its own chemodiversity or by associational resistance provided by conspecific neighbours. To investigate the role of chemodiversity in plant-aphid interactions, we used the Asteraceae Tanacetum vulgare, whose individuals differ pronouncedly in the composition of leaf terpenoids, forming distinct chemotypes. Plants were set-up in a field consisting of 60 plots, each containing five individuals of either the same or different chemotypes. Presence of winged aphids, indicating aphid attraction, and abundance of winged and unwinged aphids, indicating fitness, were scored weekly on each plant, focusing on three commonly occurring aphid species specialised on T. vulgare. During the peak abundance of aphids, leaf samples were taken from all plants for re-analyses of the terpenoid composition and quantification of terpenoid chemodiversity, calculated on an individual plant (Shannon index, Hsind) and plot level (Hsplot). Aphid attraction was neither influenced by chemotype nor plot-type. The real-time odour environment may be very complex in this setting, impeding clear preferences. In contrast, the abundance was affected by both chemotype and plot-type. On average, more Uroleucon tanaceti aphids were found on plants of two of the chemotypes growing in homogenous compared to heterogenous plots, supporting the associational resistance hypothesis. For Macrosiphoniella tanacetaria the probability of presence on a plant differed between plot-types on one chemotype. Terpenoid chemodiversity expressed as a gradient revealed negative Hsplot effects on U. tanaceti, but a positive correlation of Hsind with the abundance of M. tanacetaria. Aphids of M. fuscoviride were not affected by any level of chemodiversity. Synthesis. This study shows that not only the chemotype and chemodiversity of individual plants but also that of conspecific neighbours influence plant-herbivore interactions. These effects are highly specific with regard to the plant chemotype, the aphid species as well as its morphs (winged vs. unwinged). Furthermore, our results highlight the importance of analysing chemodiversity at different levels.

Journal ArticleDOI
12 Jan 2022-Planta
TL;DR: Findings indicate that both heterologous and increased native expression of the transcription factor SbWRKY86 contributes to reduced aphid levels in diverse plant models.

Journal ArticleDOI
TL;DR: It is demonstrated that the Hamiltonella associations found in nature are locally adapted both to the aphid host itself, and its ecology, in that aphids tend to carry Hamilt onella strains that provide strong protection against their dominant parasitoid species.
Abstract: Facultative symbionts are common in insects and are known to provide important adaptations that can drive rapid host evolution. Yet we still have a limited understanding of what shapes their distributions, such as why particular symbiont strains are common in some host species yet absent in other. To address this question, we genotyped the defensive symbiont Hamiltonella defensa in 26 aphid species that commonly carry this microbe. We found that Hamiltonella strains were strongly associated with specific aphid species and that strains found in one host species rarely occurred in others. To explain these associations, we reciprocally transferred the Hamiltonella strains of 3 aphid species, Acyrthosiphon pisum, Macrosiphoniella artemisiae and Macrosiphum euphorbiae, in the other host species, and assessed the impact of Hamiltonella strain on: the stability of the symbiosis, aphid fecundity, and parasitoid resistance. We demonstrate that the Hamiltonella associations found in nature are locally adapted both to the aphid host itself, and its ecology, in that aphids tend to carry Hamiltonella strains that provide strong protection against their dominant parasitoid species. Our results suggest that Hamiltonella strains function as a horizontal gene pool that aphids draw from to rapidly adapt to pressures from different natural enemies.

Journal ArticleDOI
TL;DR: High-throughput sequencing of the bacterial 16S rRNA gene used to characterize the bacterial composition and structure of the digestive tracts in three species of Formica ants and Lasius niger—species that predominantly feed on honeydew secreted by aphids found that bacterial communities displayed species- and colony-level signatures.
Abstract: Ants are evolutionarily successful species and occupy diverse trophic and habitat niches on the earth. To fulfill dietary requirements, ants have established commensalism with both sap-feeding insects and bacteria. In this study, we used high-throughput sequencing of the bacterial 16S rRNA gene to characterize the bacterial composition and structure of the digestive tracts in three species of Formica ants and Lasius niger (Linnaeus)—species that predominantly feed on honeydew secreted by aphids. We found that bacterial communities displayed species- and colony-level signatures, and that bacterial communities in the infrabuccal pockets and crops were different from those in the midguts and hindguts. Lactobacillus and Wolbachia were dominant in the infrabuccal pockets and crops of workers, whereas Wolbachia was dominant in the midguts, hindguts and brood (larvae, pupae and cocoons). To learn more about the dominant Lactobacillus in ants, we assessed its prevalence in a wide range of aphid-tending ants using diagnostic PCR. We found that Lactobacillus was more prevalent in Formicinae than in Myrmicinae species. We also isolated four strains of lactic acid bacteria (Lactobacillus sanfranciscensis, Lactobacillus lindneri, Weissella cibaria and Fructobacillus sp.) from the infrabuccal pockets and crops of aphid-tending ants using a culture-dependent method. Two predominant lactic acid bacterial isolates, Lactobacillus sanfranciscensis (La2) and Weissella cibaria (La3), exhibited abilities in catabolizing sugars (sucrose, trehalose, melezitose and raffinose) known to be constituents of hemipteran honeydew. These findings contribute to further understanding the association between ants, aphids and bacteria, and provide additional information on the function of lactic acid bacteria in ants.

Journal ArticleDOI
24 May 2022-Insects
TL;DR: In this article , the authors evaluated the population life tables and flight performance of Eupeodes corollae Fabricius and found that the larval survival rate on M. japonica was significantly lower than on A. craccivora and M. persicae.
Abstract: Simple Summary As a candidate for controlling aphid populations, Eupeodes corollae Fabricius also performs a pollination function which is critical to agricultural systems. We evaluated the population life tables and flight performance of E. corollae fed on three prey species (Aphis craccivora Koch, Myzus persicae Sulzer and Megoura japonica Matsumura) to select suitable aphid species for keeping E. corollae indoors. The results showed that E. corollae completed development and reproduction on these three aphid species while achieving the shortest generation time, the maximum fecundity, and the highest intrinsic natural growth rate and flight ability on M. japonica. Our study indicated that M. japonica is the most suitable prey for E. corollae, providing a basis for utilizing the ecological service function of the hoverfly. Abstract Eupeodes corollae Fabricius, as one of the most common beneficial predatory insects in agricultural ecosystems, provides pollination and biological control services that help improve crop yield and maintain biodiversity. However, systematic research is needed on the species of aphids used for propagation. To develop highly fit populations of the important insect predator and crop pollinator, E. corollae, for research and commercial use, further research is needed to develop the most nutritious diet and efficient propagation methods. Here, the fitness of E. corollae was assessed in the laboratory after larvae were fed an aphid diet of Aphis craccivora Koch, Myzus persicae Sulzer or Megoura japonica Matsumura. The larval survival rate on M. japonica was significantly lower than on A. craccivora and M. persicae. The developmental duration for larvae (7.6 d) and pupae (6.9 d) was longest on A. craccivora. The pupal emergence rate on A. craccivora (98.0%) was significantly higher than on the other two, and lowest (64.7%) on M. japonica. On A. craccivora, M. persicae, and M. japonica, respectively, the generation time was 24.85 d, 23.12 d and 21.05 d; the value for the intrinsic rate of natural increase was 0.19, 0.20, and 0.21; and the value for the finite rate of increase was 1.21, 1.22, and 1.23. For flight variables, E. corollae attained the fastest velocity and longest distance and duration on M. japonica. The M. japonica diet, thus, provided the shortest generation time, the highest intrinsic rate of natural increase and finite rate of increase, the maximum fecundity and the greatest flight ability. Thus, to improve the survival rate of E. corollae larvae, A. craccivora or M. persicae can be used to feed newly hatched larvae, and M. japonica can be used for second- and third-instar larvae. These results provide a theoretical basis for feeding E. corollae and optimizing its ecosystem services.