Aphid Aphis Gossypii Research Articles

The endocuticle structural glycoprotein AgSgAbd-2-like is required for cuticle formation and survival in the melon aphid Aphis gossypii.

Cuticular proteins are essential for cuticle formation, molting, and survival in insects. However, functional analysis of cuticular proteins in the melon aphid has been limited. In this study, we identified an endocuticle structural glycoprotein (ESG) AgSgAbd-2-like in the melon aphid Aphis gossypii, which is a member of the RR-1 subfamily of the CPR (cuticular protein containing the conserved Rebers-Riddiford motif) chitin-binding proteins. When double-stranded RNA is delivered epidermally, AgSgAbd-2-like is knocked down, resulting in molting defects and mortality. The expression of AgSgAbd-2-like is comparatively low prior to molting and increases following molting. Ecdysone signaling consistently suppresses AgSgAbd-2-like. Histologically, the endocuticle and whole cuticle are thinner in AgSgAbd-2-like RNA interference (RNAi) aphids, which is a leading cause of molting defects and mortality. Furthermore, knockdown of any other homolog of ESGs, including AgSgAbd-4, AgSgAbd-4-like, AgSgAbd-8-like, and AgSgAbd-9-like, results in molting defects and death, like that by AgSgAbd-2-like RNAi. These results indicate that the melon aphid ESGs are conserved in cuticle formation and could be potential targets for RNAi-based pest management.

Resistance of Aphids (Aphis gossypii) to Different Types and Concentrations of Synthetic Insecticides

Resistance of Aphids (Aphis gossypii) to Different Types and Concentrations of Synthetic Insecticides

Monitoring the Distribution, Incidence, and Symptom Expression Associated with Cotton Leafroll Dwarf Virus in the Southern United States Using a Sentinel Plot System

Cotton leafroll dwarf virus (CLRDV), transmitted by the cotton aphid ( Aphis gossypii Glover), was first confirmed in upland cotton ( Gossypium hirsutum L.) in Alabama, U.S.A., in 2017. Subsequent observations of symptomatic plants followed by virus infection confirmation via reverse transcriptase PCR (RT-PCR) were made in neighboring states in 2018. To assess the distribution and incidence of CLRDV and the occurrence of presumed symptoms across the southern cotton belt, a multidisciplinary team established sentinel plot survey sites at 16 experiment stations in 11 states stretching from Texas to Virginia and Tennessee to Florida beginning in 2019. Field trials were conducted over a 3-year period using multiple cotton cultivars that were adjusted annually. Cotton plots were evaluated at each location by a single evaluator to attempt to correlate symptom occurrence across the cotton-growing region with virus incidence in cotton plant tissues using RT-PCR. Symptom incidence, based on visual estimation of plants in each plot with presumed symptoms, differed across the region and ranged from 0 to 75%, with a low average over all locations of 11.4% in 2021 to an average high of 28.0% in 2020. Though symptom incidence suggested the presence of CLRDV, there were instances where apparent symptoms were observed but virus presence was not confirmed by RT-PCR. CLRDV has since been confirmed from all locations, which suggests that it has become endemic in cotton production areas throughout the eastern range of the United States. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Impact of Plant Growth-promoting Rhizobacteria on the Incidence of Aphids (Aphis gossypii) in Okra

Okra (Abelmoschus esculentus L. Moench) is a widely cultivated vegetable in Asia, facing ongoing challenges from aphids (Aphis gossypii Glover). A field study was conducted on a microplot in Kasilingapuram, Karungulam block, Thoothukudi district, during the Rabi season of 2020 and the Summer of 2021. Various plant growth-promoting rhizobacteria (PGPRs) were applied to the hybrid COBh 4 okra cultivars through soil, seed, and foliar treatments, and their impact on aphid populations was assessed. The findings revealed a significant reduction in aphid numbers and enhanced production of defensive compounds and enzymes in plants treated with Bacillus subtilis Bbv57 during both the seasons. These results suggest that incorporating PGPRs could be an effective strategy for managing aphid populations by boosting up the biochemical compounds in okra cultivation and can be incorporated in IPM practices.

A near-complete genome reveals the population evolution of the cotton-melon aphid Aphis gossypii

The cotton-melon aphid Aphis gossypii Glover is a severe pest worldwide. Interhaplotype genomic variation can be used as a starting point to analyze the adaptability of Ap. gossypii. In this study, we utilized long-read PacBio HiFi sequencing and HiC scaffolding techniques to assemble a near telomere-to-telomere gap-free genome assembly of Hap4. The assembly had two gaps totaling 321.24 Mb. We characterized five telomeric repetitive regions (GGTTA)n, including the four found at the 3′ end of the chromosomes, and obtained new structural information about the telomeres. Due to the improved sequencing technology, we also identified more than 55.03 Mb of repetitive DNA in the genome assembly of Hap4, which contributed significantly to the increase in genome size compared to that of Hap1 and Hap3. Most of the additional repetitive DNA content was located on the X chromosome, and the tandem repeat sequence occupied 16.8% of the X chromosome length. The Hap4 assembly showed that the X chromosome exhibited a greater abundance of AT-rich satDNA arrays (11 satDNA arrays longer than 100 kb) than that observed in the autosomes (A1 and A2 harboured 3 and 1 satDNA arrays). We detected presence-absence variations, insertions, and deletions events between Hap1, Hap3, and Hap4 Ap. gossypii, which had significant effects on gene expression. Additionally, we identified a male-specific glyceraldehyde-3-phosphate dehydrogenase of fungal origin in all strains of Ap. gossypii. This comprehensive genome assembly provides valuable insights into the structural characteristics of highly repetitive regions and allows comparative genomic analyses that facilitate our understanding of Ap. gossypii's adaptation and diversification.

Psyllid‐mite interactions promote psyllid fecundity by selecting for a different life history

AbstractBACKGROUNDIn interspecific competitive interactions at the same trophic level, herbivores are often hypothesized to exhibit a fast life‐history strategy characterized by early reproduction and a short lifespan. Here, we analyzed the shift in life history of the psyllid Bactericera gobica when it interacts with the aphid Aphis gossypii, the thrips Frankliniella occidentalis, or the mite Aceria pallida in similar ecological niches because all of them cause damage to goji berry leaves.RESULTSWe found that psyllids displayed a typical fast life history when interacting with aphids and thrips. Psyllids that interacted with mites also reproduced earlier than those without any interactions, but later than those interacting with aphids and thrips. Trophic competition typically led to a loss of fecundity in psyllids. To mitigate this loss, psyllids that interacted with mites allocated more resources to reproduction compared to those interacting with aphids and thrips, resulting in their reproduction being spread over a longer lifespan. This life history can be best described as a bet‐hedging strategy.CONCLUSIONOur study suggests that interspecific interactions cannot be solely explained by invoking faster life histories. Instead, the shift in life history may converge towards a finely‐tuned match between interacting species. Interactions between psyllids and mites increase psyllid fecundity, potentially promoting the persistence of both species. © 2024 Society of Chemical Industry.

The effect of four botanical volatile oil against aphid (Aphis gossypii) and mealybug pests (Phenacoccus solenopsis). A toxicological and chemical composition study

Given the economic damage caused by cotton mealybugs Phenacoccus solenopsis, (P. solenopsis) and aphids Aphis gossypii (A. gossypii), it was a need to look for more acceptable and safe materials. Four local plant extracts were assessed Ocimum basilicum, Origanum majorana, Pipper nigrum, and Schinus terebinthifolius represented by their volatile oils, against these two pests in the laboratory, with the following LC50 values for each applied volatile oil extract against aphid and mealybug 1938.05, 7391.33, 674.81, 5548.65, 644.45, 4383.52, 727.88, and 6735.62 ppm using the four previous extracts respectively. The highest mortality percentage was 50.0 and 49.3% for pipper nigrum, while the lowest percentage was for O. basilicum with 36.2 and 31.2% against P. solenopsis and A. gossypii, respectively. The oils that gave the highest mortality percentages pipper nigrum and Origanum majorana were analyzed using GCMS technique revealed the existence of major compounds belonging to the terpenoids chemical group, which have a noticeable role in the process of controlling these pests.

Toxicity of Clove Oil Nanoparticle Againts (Aphis gossypii) on Chili (Capsicum annum) and Its Predator (Cheilomenes sexmaculata)

One of the pests that cause economic losses in Chili (Capsicum annum L.) is aphid (Aphis gossypii Glover) (Hemiptera: Aphididae). Therefore, it is necessary to carry out alternative controls that are not damaging and detrimental to the surrounding environment including against beneficial organisms such as the natural enemy Cheilomenes sexmaculata Fabricius (Coleoptera: Coccinellidae). Clove oil and the formulation of essential oils in the form of nanoparticles have been used as a botanical pesticide. The purpose of this work is to determine the toxicity of a clove oil nanoformulation against aphids (A. gossypii) and the six-spotted zigzag ladybird predator C. sexmaculata. This work has six treatments and four replications using a fully randomized design. The results showed that clove oil nanoparticles (CO-NPs) significantly affected mortality and decreased the number of offspring of A. gossypii. The average size of the tested nanoparticles was 166.38 nm and the average zeta potential value of the tested nanoparticles was -19 mV. The CO-NPs can affect the increase in mortality and decrease in the offspring number of A. gossypii. The LC50 value of A. gossypii was 0.32% at the time of observation 48 hours after application while the LT50 value was 3 hours at a concentration of 1.2%. The percentage of decrease in the number of offspring reached 95.01% at a concentration of 1.2%. Results of calculating the selectivity ratio value (SR) showed that CO-NPs are selective against predators C. sexmaculata, with the SR value <1.

Efficacy of arginine kinase as a promising RNAi target in Aphis gossypii genome as revealed through aphid bioassay on field-grown transgenic cotton plants

The cotton aphid Aphis gossypii is a major agricultural pest of cotton that causes substantial damage to the crop not only by sucking sap but also through virus transmission. Globally adopted traditional and contemporary approaches to control aphid infestation have certain limitations and are hazardous to human health. RNA interference (RNAi) technology has unfolded its potential as an effective crop protection strategy against various pests. In this study, we adopted plant-mediated RNAi strategy to enhance aphid resistance in cotton by targeting arginine kinase (AK), which is a crucial enzyme responsible for energy homeostasis in insects. We selected a 312bp dsRNA fragment containing eight siRNAs and showing optimum GC content, Hb index, and stable secondary structure based on computational prediction studies. The binary construct expressing dsRNA was used to transform local cotton variety MNH886 and four transgenic lines were obtained in the T1 generation. Out of the four T1 transgenic cotton lines, dsA-7 exhibited the highest aphid mortality (73.3%), whereas, dsA-1, dsA-3 and dsA-6 revealed 60%, 61%, and 66.6% aphid mortality, respectively, in comparison to 13.3% mortality in the mock control cotton line. Moreover, significant knockdown in mRNA expression of AK was observed in aphids fed dsA-7 which was 79%. In comparison, 54%, 47%, and 45% downregulation was recorded in aphids which fed on dsA-6, dsA-3, and dsA-1 transgenic cotton lines, respectively. These results revealed that plant-mediated downregulation of aphid RNA induced significant RNA interference in A. gossypii which resulted in considerable aphid mortality and led to plant protection against aphids.

Abundance and diversity of cotton insect pests under repeatedly cultivated cotton fields of Tanzania.

Cotton production in Tanzania is facing significant challenges due to insect pests that cause extensive damages to the crop. The most notable pests include the African bollworm (Heliothis armigera Hubner), Spiny bollworm (Earias biplaga Walker), Cotton stainers (Dysdercus sidae (Herrich-Schaeffer), Cotton Aphids (Aphis gossypii Glover), Thrips (Thrips tabaci Lindeman), Jassids (Amrasca biguttula, Bigutula), Leafhoppers (Cicadellidae jassidae), and Whiteflies (Bemisia tabaci Genn). If left uncontrolled, these pests can cause up to 60% damage to the crop. Despite the importance of cotton and the fact that most of these pests are endemic, there are scanty knowledge on the dynamics and distribution of cotton pests across the seasons of the year and crop's phenological growth stages (germination, vegetative growth, flowering and boll formation) in areas under repeated cultivation of the crop in Tanzania. Here we report on the influence of seasons and cotton's phenological stages on the abundance, diversity, distribution and richness of cotton insect pests. The study was conducted in the Misungwi district for two cotton-growing seasons, using the UKM08 cotton variety. Stick traps and handpicking methods were deployed in catching the cotton insect pests. On average, a total of 8,500 insect specimen of diverse families and species were collected every season. The four dominant species among the collected were Aphis gossypii (17.37%), Amrasca biguttula (11.42%), Nezara viridura (10.7%), and Bemisia tabacci (10.68%). Both cotton phenological growth stages and seasons significantly (p<0.05) influenced the abundance, diversity, distribution and richness of cotton insect pests. In particular, the phenological growth stage 3 exhibited greater diversity of insect pests. The pests' distribution patterns remained relatively uniform across the crop growth stages. Findings from the present study could contribute to developing sustainable pest management strategies in areas under repeated cotton production in Tanzania and elsewhere.

Influences of Salt Stress on Cotton Metabolism and Its Consequential Effects on the Development and Fecundity of Aphis gossypii Glover.

The degree of global soil salinization is gradually deepening, which will inevitably affect agricultural ecology. It has been found that salt stress induces the resistance of host plants to phytophagous pests. However, little is known about the effects of salt-stressed cotton plants on the fitness of cotton aphids (Aphis gossypii Glover). In this study, we investigated the differences between cotton metabolomes under mild (75 mM NaCl) and moderate (150 mM NaCl) salinity conditions and their effects on the fitness of cotton aphids. The results showed that 49 metabolites exhibited significant upregulation, while 86 metabolites were downregulated, with the increasing NaCl concentration. The duration of nymphal aphids under 150 mM NaCl significantly extended to 6.31 days when compared with the control (0 mM NaCl, 4.10 days). Meanwhile, the longevity of adult aphids decreased significantly under 75 and 150 mM NaCl, with an average of 10.38 days (0 mM NaCl) reduced to 8.55 and 4.89 days, respectively. Additionally, the total reproduction number of single females decreased from 31.31 (0 mM NaCl) to 21.13 (75 mM NaCl) and 10.75 (150 mM NaCl), whereas the survival rate of aphids decreased from 81.25% (0 mM NaCl) to 56.25% (75 mM NaCl) and 34.38% (150 mM NaCl) on the 12th day. These results support the hypothesis that plants growing under salt stress are better defended against herbivores. Furthermore, 49 differential metabolites were found to be negatively correlated with the longevity and fecundity of adult aphids, while 86 different metabolites showed the opposite trend. These results provide insights into the occurrence and control of cotton aphids amidst the escalating issue of secondary salinization.

Impact of leaf trichomes and stomatal density on the response of three soybean varieties to sucking pest infestation

Chemical pesticides disrupt local ecosystems, reduce populations of natural predators, and contribute to the evolution of pest resistance. Therefore, developing pest-resistant crop varieties is one of the most promising and environmentally friendly alternatives for pest control today. In the present study field experiments were conducted over two consecutive growing seasons in 2022 and 2023 to explore pest resistance among three soybean varieties viz. Crawford, Giza 111, and Giza 22. The research aimed to assess pest infestation resistance among these varieties, considering various leaf morphological factors. Four key pests were evaluated in the study viz. whiteflies (Bemisia tabaci Genn), spider mites (Tetranychus urticae Koc), aphids (Aphis gossypii Glover), and thrips (Thrips tabaci Lind)). The soybean varieties exhibited differences in susceptibility, and pest density varied across the two growing seasons. Crawford and Giza 111 demonstrated lower resistance, characterized by reduced leaf hair density and an increased number of stomata per leaflet. In contrast, Giza 22 was the most susceptible, featuring a higher density of trichomes and lower stomata density. In terms of field yield, Crawford produced the highest yield, followed by Giza 111, while Giza 22 yielded the least. The results of this study underscore the importance of selecting resistant plant varieties in future pest resistance improvement programs.

The Belowground-Aboveground Interactions of Zucchini: The Effects of Trichoderma afroharzianum Strain T22 on the Population and Behavior of the Aphid Aphis gossypii Glover and Its Endoparasitoid Aphidius colemani Viereck.

Fungi belonging to the genus Trichoderma have received high consideration in agriculture due to their beneficial effects on crops from their plant promotion effects and protection from disease. A role of Trichoderma fungi in triggering plant defense mechanisms against insect pests, either directly or by natural enemy attraction, has been proposed, even if the results in different studies are controversial. In this present study, using zucchini plants as a model species, we investigated the effects of Trichoderma afroharzianum strain T22 plant inoculation on the cotton aphid Aphis gossypii and its endoparasitoid Aphidius colemani. Our results showed that the inoculation with T. afroharzianum T22 promotes A. gossypii population growth and makes zucchini more attractive to the aphid. The higher abundance of aphids on Trichoderma-inoculated zucchini was compensated for by a higher presence of the mummies of Aphidius colemani. In this present study, we recorded a higher zucchini biomass, thereby confirming that Trichoderma can act as a plant growth inducer.

Succession of Major Pests and Predatory Fauna in Okra

Investigations on pest succession in okra crops were carried out during kharif, 2023 at the Department of Entomology, B. A. College of Agriculture, Anand Agricultural University, Anand. Pest succession based on crop growth stages showed that the population of sucking insect-pests viz., jassid (Amrasca biguttula biguttula Ishida), aphid (Aphis gossypii Glover), whitefly (Bemisia tabaci Gennadius.) observed from vegetative stage and remained up to crop matured while, red spider mite, Tetranychus cinnabarinus incidence appeared from reproductive stage to maturity stage. Among the lepidopteran pests, the infestation of semi-looper, Anomis flava (Fabricius) started in the second week after germination and remained till maturity of the crop whereas, shoot and fruit borer (Earias insulana Boisd.) and fruit borer (Helicoverpa armigera (Hubner) Hardwick) damaged the crop from the vegetative stage and remained up to crop maturity. Coccinellids and spider activity initiated with sucking insect-pest incidence and remained up to crop maturity. The weather parameters, Bright sunshine hours and maximum minimum temperature had significant relationships with A. biguttula biguttula, T. cinnabarinus, E. vittella and H. armigera. Whereas, relative humidity significantly negatively influenced the activity of red spider mite, E. vittella, H. armigera and positively on predator coccinellids. Furthermore, windspeed had a significant positive association with A. biguttula biguttula and E. vittella (shoot damage) while, negative with H. armigera larva.

Efficacy of newer insecticides against aphids (Aphis gossypii Glover) in Bt cotton

Efficacy of newer insecticides against aphids (Aphis gossypii Glover) in Bt cotton

Antioxidant Enzyme, Transcriptomic, and Metabolomic Changes in Lily (Lilium spp.) Leaves Induced by Aphis gossypii Glover.

Cotton aphids (Aphis gossypii Glover) cause harm by feeding on phloem sap and spreading plant viruses to lily. Understanding the mechanisms by which aphids infest lily plants is crucial for effective aphid management and control. In this study, we investigated the activity of antioxidants, integrated nontargeted metabolomes and transcriptomes of lilies infested by cotton aphids to explore the changes in lily leaves. Overall, the results indicated that the catalase (CAT) activity in the leaves of the lily plants was greater than that in the leaves of the control plants. A comprehensive identification of 604 substances was conducted in the leaves. Furthermore, the differentially abundant metabolite analysis revealed the enrichment of phenylalanine metabolism and α-linolenic acid metabolism. Moreover, 3574 differentially expressed genes (DEGs), whose expression tended to increase, were linked to glutathione metabolism and phenylpropanoid biosynthesis. In addition, the integrated analysis revealed that the defensive response of lily leaves to aphids is manifested through antioxidant reactions, phenylpropane and flavonoid biosynthesis, and α-linolenic acid metabolism. Finally, the key metabolites were CAT, glutathione, coumaric acid, and jasmonic acid, along with the key genes chalcone synthase (CHS), phenylalanine ammonia-lyase (PAL), and 12-oxo-phytodienoic acid reductase (OPR). Accordingly, the findings of this research elucidate the molecular and metabolic reactions of A. gossypii in lily plants, offering valuable insights for developing aphid resistance strategies in lily farming.

Effectiveness Formulation of Tobacco and Tannin Fermentation Extract against Aphids (Aphis gossypii Glover) on Curly Red Chilli

Effectiveness Formulation of Tobacco and Tannin Fermentation Extract against Aphids (Aphis gossypii Glover) on Curly Red Chilli

Exploring selected bioinsecticides for management of cotton aphids (Aphis gossypii Glover) of brinjal in Bangladesh

Brinjal (Solanum melongena L.) is a popular vegetable in Bangladesh being nutritious, tasty, and cultivable throughout the year. Insect pests are the major constraint to its successful cultivation and production. The present study was conducted during the winter season when the sucking insect pests especially cotton aphids (Aphis gossypii Glover) are most abundant. Aphid infestation was observed in the brinjal plants since the early vegetative stage and sometimes the infestation rate reached up to 100 percent. Moreover, the infestation rate fluctuated with plants or duration. Aphids suck the cell saps resulting in stunting the growth of plants and yield reduction. As brinjal is consumed without peeling, contamination with toxic insecticides is a health concern. To address this, some bioinsecticides including abamectin preparation ‘Biomax M’, sodium lauryl ether sulphate preparation ‘Fizimite’, azadirachtin preparation ‘Fytomax’, Saccharopolyspora spinosa and Bacillus thuringiensis var. Kurstaki broth mixture preparation ‘Spinomax’, and potassium salt of fatty acid preparation ‘Fytoclean’ were selected to combat aphids. Besides, Voliam Flexi was applied as chemical control. A field study showed that abamectin preparation Biomax M was very potent against aphids showing zero percent aphid infestation. In addition, the chemical control Voliam Flexi 300 SC also provided zero percent aphid infestation. Therefore, Biomax M might be the non-toxic alternative to Voliam Flexi 300 SC for controlling aphids.

Impact of biopesticides on the probing and feeding behavior of Aphis gossypii

BackgroundPesticides-induced mortality has traditionally been the toxicological endpoint on which a chemical is selected for pest management strategies. However, the exposure to a pesticide might also cause behavioral alterations that can dramatically affect the dynamics of pest-plant interaction. Understanding these non-lethal effects is crucial for developing comprehensive and sustainable pest control measures.MethodsHere, using the Electrical Penetration Graph (EPG) technique, we evaluated whether biopesticides routinely used in organic or conventional pest management might alter the probing and feeding behavior of the cotton aphid Aphis gossypii on treated plants. The post exposure persistence of feeding alterations when moving the insect onto clean plants was also assessed. The tested biopesticides were chosen for being aphicides or because used in those crops hosts of A. gossypii. Generalised linear mixed models were fitted to analyse the effects of biopesticides on the probing and feeding behavior of aphids, using untreated control data as a model baseline.ResultsResiduals of Bacillus thuringiensis, Beauveria bassiana, and sulfur significantly affected the dynamics of the stylets intercellular route compared to the control (namely, shorter pathways, fewer and shorter brief intracellular stylets probes, higher and longer derailed stylets events). Mineral oil, orange essential oil and pyrethrin delayed or impaired the onset of phloem sap ingestion. On the other hand, copper and potassium salts promoted feeding. Pyrethrin was the only biopesticides inducing persistent behavioral alterations, with insects displaying a higher frequency of occurrence of xylem ingestion events when moved to untreated plants after exposure.ConclusionsOverall, this study demonstrates that biopesticides modulate the aphid-plant interactions by impairing or facilitating the exploitation of the host plant, also affecting the patterns conducive to plant pathogens transmission. This study also highlights the importance of considering in toxicological studies the impact of all the compounds the pest could be exposed to within the agroecosystem, including those not designed for that specific pest.

The discovery of indazapyroxamet: a novel 3-pyridinyl insecticide targeting piercing/sucking insectsa.

In recent years, the registrations for a number of commercial insecticides utilized for piercing/sucking insects have been cancelled or restricted. To meet this growing need for new hemipteran controlling agrochemicals, we discovered a 2-(pyridin-3-yl)-thiazole compound, with limited insecticidal activity against cotton/melon aphid (Aphis gossypii). The 2-(pyridin-3-yl)-thiazole moiety offered us a basis to pursue the bicyclic 2-(pyridin-3-yl)-2H-indazole carboxamides. Evaluation of such 2-(pyridin-3-yl)-2H-indazole carboxamides revealed that even analogs containing only simple alkyl amides attached at the 4 or 5 positions possess promising insecticidal activity. Extensive optimization of this novel class of 2-(pyridin-3-yl)-2H-indazole carboxamides led to identifying indazapyroxamet for commercial development. © 2024 Society of Chemical Industry.