棉蚜Aphis gossypii Glover在不同寄主上的体色分化研究

对不同寄主上不同时期棉蚜的体色分化进行比较研究 结果表明 ,棉蚜自然种群由黄色型和绿色型 2种个体组成 .在木槿、石榴和花椒 3种越冬寄主上 ,早春以绿色型个体为主 ,春末夏初黄色型个体逐渐占优势 ,夏末秋初又以绿色型个体为主 ;在夏季寄主棉花上 ,黄色型个体一直占优势 ,其中 5～ 6月份棉花苗期可见到部分绿色型个体 ,所占比例与越冬寄主上棉蚜迁出时所占的比例基本接近 .在室内不同温度条件下连续饲养不同体色棉蚜的试验结果表明 ,绿色型棉蚜可分化出绿色型和黄色型 2种后代 ,后代的体色变化与温度密切相关 ,在温度较高时黄色型后代占优势 ,在温度较低时绿色型后代占优势 ,而且黄色型后代随温度的降低也会产生出绿色型后代 .系统饲养黄色干母的后代还发现 ,不论饲养温度如何变化 ,其后代均为黄色型 ,表明自然界有

山东省主要菜区瓜(棉)蚜(Aphis gossypii Glover)抗药性及机理研究

利用毛细管点滴法测定了山东省 4个主要菜区瓜 (棉 )蚜 (Ap his gossypiiGlover)对氰戊菊酯、吡虫啉、氧乐果和灭多威的抗性。结果表明 ,聊城种群对氰戊菊酯的抗性高达 12 1710 .1倍 ,对吡虫啉、氧乐果和灭多威也分别产生了 9.6、2 9.4及 7.9倍的抗性 ;寿光种群对氰戊菊酯的抗性也高达 2 74 59.3倍 ,对吡虫啉、氧乐果和灭多威的抗性分别为 4 .1、18.1及 2 .9倍 ;苍山、泰安两种群对 4种药剂的抗性亦有不同程度的提高。离体酶活性和增效剂测定结果表明 ,聊城种群的抗药性与多功能氧化酶、羧酸酯酶、谷胱甘肽转移酶和乙酰胆碱酯酶活力提高均有关系。

Cloning and Sequencing of Two Acetylcholinesterase cDNA Fragments from Cotton Aphid,Aphis gossypii Glover

Two acetylcholinesterase (AChE) genes cDNA fragments,Ag.acel and Ag.ace2,have been cloned from cotton aphid,Aphis gossypii Glover using degenerate primers with RT-PCR technique.Ag.acel gene cDNA fragment is of 282?bp encoding 94 amino acids,and Ag.ace2 gene cDNA fragment is of 264?bp encoding 88 amino acids.Both two putative AChE genes cDNA fragments share numerous similarities with those cloned from other insects.This is the first report of two AChE cDNA fragment sequences in the insect species,which provided the direct evidence of multiple AChE existence in insects.

Resistance development,cross-resistance,and fitness costs associated with Aphis gossypii resistance towards sulfoxaflor and acetamiprid in different geographical regions

Aphis gossypii has become increasingly difficult to manage due to its strong insecticide resistance.In the laboratory,we established sulfoxaflor-resistant and acetamiprid-resistant strains in two A.gossypii populations with different basal insecticide resistance levels,and evaluated the effects of basal insecticide resistance on the resistance development and cross-resistance,as well as differences in fitness.Under the same selection pressure,Yarkant A.gossypii(with low basal insecticide resistance)evolved resistance to sulfoxaflor and acetamiprid more quickly than Jinghe A.gossypii(with high basal insecticide resistance),and the evolution of A.gossypii resistance to sulfoxaflor developed faster than acetamiprid in both Yarkant and Jinghe,Xingjiang,China.The sulfoxaflor-resistant strains selected from Yarkant and Jinghe developed significant cross-resistance to acetamiprid,imidacloprid,thiamethoxam and pymetrozine;while the acetamiprid-resistant strains developed significant cross-resistance to sulfoxaflor,imidacloprid,thiamethoxam,pymetrozine,and chlorpyrifos.The relative fitness of A.gossypii decreased as the resistance to sulfoxaflor and acetamiprid developed.The relative fitness levels of the sulfoxaflor-resistant strains(Yarkant-SulR and Jinghe-SulR)were lower than those of the acetamipridresistant strains(Yarkant-AceR and Jinghe-AceR).In addition,the relative fitness levels of sulfoxaflor-and acetamiprid-resistant strains were lower in Jinghe than in Yarkant.In summary,basal insecticide resistance of A.gossypii and insecticide type affected the evolution of resistance to insecticides in A.gossypii,as well as cross-resistance to other insecticides.The sulfoxaflor-and acetamiprid-resistant A.gossypii strains had obvious fitness costs.The results of this work will contribute to the insecticide resistance management and integrated management of A.gossypii.

A sublethal concentration of afidopyropen suppresses the population growth of the cotton aphid, Aphis gossypii Glover(Hemiptera: Aphididae)

The cotton aphid,Aphis gossypii Glover(Hemiptera:Aphididae),is an important insect pest of cotton crops worldwide.The objectives of this study were to determine the acute toxicity of afidopyropen and whether there are any effects of sublethal concentrations of afidopyropen on the biological characteristics of A.gossypii.The results showed that afidopyropen possesses high acute toxicity to adult A.gossypii with a 72 h LC_(50) value of 1.062 mg L^(–1).A sublethal concentration(LC_(10))of afidopyropen significantly decreased adult longevity,fecundity and oviposition days of female adults in both F0 and F1 generations.The total pre-adult survival of F_(1) progeny was also significantly reduced by 30%at the LC_(10) of afidopyropen.In addition,the nymph developmental time,pre-adult period,adult pre-reproductive period(APRP),and total pre-reproductive period(TPRP)of the F1 progeny were significantly prolonged compared with the control.Several population parameters,including the net reproductive rate(R_(0)),intrinsic rate of increase(r)and finite rate of increase(λ)of F_(1) progeny were significantly decreased by a sublethal afidopyropen concentration exposure.These results indicated that sublethal concentration of afidopyropen can significantly suppress A.gossypii population growth.It would be useful for assessing the overall effects of afidopyropen on A.gossypii.

棉蚜Aphis gossypii Glover在棉花不同品种上的生长繁育和排蜜的研究

在室內饲养不同品种棉苗上的棉蚜,其生长、敏育和排蜜情况有显著差异。我们对新疆主栽的6个棉花品种上棉蚜的平均相对生长量、个体生殖力、种群数量增殖率和棉蚜排泄的蜜滴直径、蜜滴重量、棉蚜排蜜频率等进行了研究,并对棉花品种的內部含糖量进行了测定。在供试的棉花品种中,“军棉一号”和“大铃棉”叶片內部含糖量高,其相应地棉蚜生长发育快,排蜜量也多;长绒棉“新海三号”和“新海七号”次之;而“新陆早一号”和“新陆中一号”上的棉蚜相对生长发育慢,排蜜量也少。

棉蚜(Aphis gossypii)种群寄主分化和季节分化的微卫星引物PCR研究

通过对棉蚜群体进行室外观察、室内培养和分子遗传标记的 DNA多态性分析 (用 3个微卫星序列为引物进行PCR)等研究 ,结果表明 :1 .冬寄主 (木槿、石榴和花椒 )上棉蚜种群分化较小 (种群相似性指数在 0 .833～ 0 .91 7之间 ) ,而冬寄主种群和夏寄主 (棉花和南瓜 )种群之间有较大的分化 (种群相似性指数在 0 .589～ 0 .756之间 )。2 .棉蚜自然种群是由体色不变的生物型 (干母为黄色 ,其后代始终为黄色 )和体色可变型生物型 (干母为绿色 ,其后代有绿色和黄色两种体色 )组成的混合种群。3.黄色小型蚜 (伏蚜 )来源于混合类群 ,但主要来自绿色干母多代选择分化的黄色后代 。

Effect of Transgenic Bt plus CpTI Cotton on Carboxylesterase and Acetylcholinesterase of Cotton Aphid Aphis gossypii

[Objective] The research aimed to assess the effect of transgenic Bt plus CpTI cotton variety SGK321 on carboxylesterase and acetylcholinesterase of cotton aphid Aphis gossypii and provide theoretical basis for studying the biosafety of transgenic cotton.[Method] Cotton aphids were fed with SGK321 and Shiyuan321（normal parental varieties） for over 40 generations.Enzyme activities were compared between cotton aphids feeding on SGK321 for 1,2,3,41,42 and 43 generations with those on Shiyuan321.[Result] The carboxylesterase activity of cotton aphids feeding on SGK321 for 1 generation was significantly higher than those feeding on Shiyuan321.Acetylcholinesterase activity of cotton aphids feeding on SGK321 for 1,2 and 3 generations were significantly higher than those feeding on Shiyuan321 in the same generation.But there was no significant difference of enzyme activity between cotton aphids feeding on SGK321 for a long term and those feeding on parental cotton.[Conclusion] The cotton aphid that feeding on transgenic Bt plus CpTI cotton SGK321 for a long time has adaptivity to SGK321 by regulating the detoxifying enzyme.

七星瓢虫(Coccinella septempunctata)捕食棉蚜(Aphis gossypii)的功能反应:实验与模拟(英文)

室内研究了５个温度条件（１５、２０、２５、３０和３５±０．５℃）下，七星瓢虫（Ｃｏｃｉｎｅｌａｓｅｐｔｅｍｐｕｎｃｔａｔａ）５个捕食虫态对棉蚜（Ａｐｈｉｓｇｏｓｙｐｉ）３个体积组的功能反应。测试温度范围内，瞬时攻击率（ｓｅａｒｃｈｒａｔｅ）和处置时间（ｈａｎ－ｄｌｉｎｇｔｉｍｅ）随捕食者龄期的增长而增加；每一捕食者虫态内，搜索率随猎物体积的增加而上升，而处置率则下降；搜索率随温度增加直线上升，而处置率则呈曲线上升。田间罩笼内研究了５个捕食者虫态对棉蚜混合种群的捕食功能，其捕食率远远低于室内实验。应用复合捕食方程并结合叶面积的影响对七星瓢虫捕食棉蚜的功能进行了模拟研究，且模拟值与观察值吻合程度较好。本研究表明，虽然七星瓢虫—棉蚜系统比较复杂，可以应用本研究探讨的方法建立模拟模型，以准确预测田间棉蚜的种群动态。

The influence of Tetranychus cinnabarinus-induced plant defense responses on Aphis gossypii development

Carmine spider mites （Tetranychus cinnabarinus） and cotton aphids （Aphis gossypii） are both serious pests of cotton, and cause reductions in yields of this key agricultural crop. In order to gain insights into how plant defense responses induced by one herbivore species affect the behavior and performance of another, we examined how infestation with T. cinnabarinus influences the development of A. gossypfi using cotton as a model. In this study, we measured the activities of several important biochemical markers and secondary metabolites in the leaves of cotton seedlings responding to infestation by T. cinnabarinus. Furthermore, the influences of T. cinnabarinus infestation on the development ofA. gossypfi in cotton were also examined. Our data showed that the activities of several key defense enzymes, including phenylalanine ammonia-lyase （PAL）, peroxidase （POD）, lipoxygenase （LOX）, and polyphenol oxidase （PPO）, were substantially increased in cotton seedlings responding to spider mite infestation. Further, the contents of gossypol and condensed tannins, key defensive compounds, were significantly enhanced in leaves of cotton seedlings following T. cinnabarinus infestation. Moreover, the T. cinnabarinus-induced production of defense enzymes and secondary metabolites was correlated with infestation density. The developmental periods of A. gossypii on cotton seedling leaves infested with T. cinnabarinus at densities of 10 and 15 individuals cm-2 were 1.16 and 1.18 times that of control, respectively. Meanwhile, the mean relative growth rates of A. gossypfi on cotton leaves infested with T. cinnabarinus at densities of 8, 10 and 15 individuals cm-2 were significantly reduced. Therefore, these data suggested that the developmental periods of A. gossypfi were significantly lengthened and the mean relative growth rates were markedly reduced when cotton aphids were reared on plants infested with high densities of spider mites. This research sheds light on the role that inducible defense responses played in plant-mediated interspecific interactions between T. cinnabarinus and A. gossypfi.

The damage risk evaluation of Aphis gossypii on wheat by host shift and fitness comparison in wheat and cotton

Aphids are considered as one of the key pests for wheat production worldwide. Major aphid species that infest wheat in China include Sitobion avenae, Rhopalosiphum padi, Schizaphis graminum and Metopolophium dirhodum. However, during our wheat field survey in Wenshang County of Shangdong＇Province, China, we observed that Aphis gossypii can feed on wheat. The damage risk of A. gossypii on wheat was assessed using host shift method. A population of A. gossypii collected from a wheat field in 2015 and another population reared on cotton under laboratory conditions for a decade without exposure to insecticides were used in the study. The results of host shift demonstrated that the A. gossypfi colony from wheat has not yet developed wheat specialization. Moreover, the assessment of A. gossypii fitness on wheat and cotton showed that fecundity and net reproductive rate of A. gossypii population fed on wheat was significantly higher comparing to the population fed on cotton, whether the initial host of A. gossypii population was wheat or cotton. This study raises a warning that the cotton aphid has potential to establish well on wheat and it may cause significant effects under specific circumstances. Therefore, future studies are required to evaluate the effects of A. gossypfi on wheat production.

Comparative transcriptional analysis and identification of hub genes associated with wing differentiation of male in Aphis gossypii

Background:Aphis gossypii Glover(Hemiptera:Aphididae),a worldwide polyphagous phloem-feeding agricultural pest,has three wing morphs(winged parthenogenetic female,gynopara,and male)in the life cycle.The exclusive males could fly from summer hosts to winter hosts,which are essential for gene exchanges of cotton aphid populations from different hosts or regions.However,the molecular mechanism of wing differentiation of male in A.gossypii remains unclear.Results:Morphological observation of male A.gossypii showed that there is no distinct difference in the external morphologies of the 1st and 2nd instar nymphs.The obvious differentiation of wing buds started in the 3rd instar nymph and was visible via naked eyes in the 4th instar nymphal stage,then adult male emerged with full wings.According to morphological dynamic changes,the development of wings in males were divided into four stages:preliminary stage(the 1st instar to 2nd instar),prophase(the 3rd instar),metaphase(the 4th instar),anaphase(the 5th instar).Results of feeding behavior monitoring via EPG(electrical penetration graph)technology indicated that although the male cotton aphids had strong desire to feed(longer duration of C 55.24%,F 5.05%and Pd waves 2.56%),its feeding efficiency to summer host cotton was low(shorter E13.56%and E2 waves 2.63%).Dynamic transcriptome analysis of male aphid at 5 different developmental periods showed that in the 3rd instar nymph,the number of up-regulated DEGs was significant increased,and time-course gene transcriptional pattern analyses results also showed that numerous genes categorized in clusters 3,5,and 8 had the highest expressed levels,which were consistent with morphological changes of wing buds.These results indicate that the 3rd instar nymph is the critical stage of wing bud differentiation in males.Furthermore,through pathway enrichment analysis of DEGs and WGCNA,it revealed that the neuroactive ligand-receptor interaction,Ras signaling pathway,dopaminergic synapse,circadian entrainment and the corresponding hub genes of PLK1,BUB1,SMC2,TUBG,ASPM,the kinesin family members(KIF23,KIF20,KIF18-19)and the novel subfamily of serine/threonine(Aurora kinase A and Aurora kinase B)probably played an important role in the critical stage of wing bud differentiation.Conclusion:This study explored morphological changes and genes transcriptional dynamics males in cotton aphid,revealed the phenomenon of low feeding efficiency of winged males on summer host cotton,and identified key signaling pathways and potential hub genes potentially involved in wing bud differentiation of male in A.gossypii.

Biochemical Characterization of Detoxifying Enzymes in Dimethoate-Resistant Strains of Melon Aphid, Aphis gossypii(Hemiptera: Aphididae)

The melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae), is a highly polyphagous sap sucking pest on wide varieties of crops including cotton and vegetables. It is a notorious vector of many plant viruses that are persistently and non-persistently transmitted. In nature, aphids are regulated by their natural enemies. However, chemical control remains a major management tool even though resistance to insecticides has been documented worldwide. A better understanding of mechanisms by which insecticide resistance occurs and its early detection is desirable to develop effective management strategies. The present investigation was conducted to study the development of resistance to an organophosphate (OP) compound-dimethoate, identify biochemical mechanism(s) involved in resistance and study cross-resistance to imidacloprid in laboratory selected A. gossypii strains in comparison to susceptible strains. Bioassay studies revealed that the LC50 values increased dramatically with dimethoate selection in resistant strains and the resistance ratio (RR) was 270-, 243- and 210-fold greater than that of the susceptible strains by 30th generation. Further, biochemical assays revealed enhanced activities of carboxylesterases (CarE), glutathione S-transferases (GSTs) and cytochrome P450-mediated p-Nitroanisole O-demethylase (PNOD) in resistant strains supporting their role in dimethoate detoxification. This study thus revealed that enhanced activity of detoxifying enzymes viz., CarE, GSTs and PNODs is one of the mechanisms underlying dimethoate resistance in A. gossypii collected from South India. Interestingly, the possibility of negatively correlated cross-resistance to imidacloprid was identified in three OP- resistant strains exhibiting 2.97-, 2.56- and 3.76-fold sensitivity to imidacloprid (a novel neonicotinoid). This indicated that the latter was less affected by the resistance mechanism(s) present.

Biochemical Characterization of Detoxifying Enzymes in Dimethoate-Resistant Strains of Melon Aphid, <i>Aphis gossypii</i>(Hemiptera: Aphididae)

The melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae), is a highly polyphagous sap sucking pest on wide varieties of crops including cotton and vegetables. It is a notorious vector of many plant viruses that are persistently and non-persistently transmitted. In nature, aphids are regulated by their natural enemies. However, chemical control remains a major management tool even though resistance to insecticides has been documented worldwide. A better understanding of mechanisms by which insecticide resistance occurs and its early detection is desirable to develop effective management strategies. The present investigation was conducted to study the development of resistance to an organophosphate (OP) compound-dimethoate, identify biochemical mechanism(s) involved in resistance and study cross-resistance to imidacloprid in laboratory selected A. gossypii strains in comparison to susceptible strains. Bioassay studies revealed that the LC50 values increased dramatically with dimethoate selection in resistant strains and the resistance ratio (RR) was 270-, 243- and 210-fold greater than that of the susceptible strains by 30th generation. Further, biochemical assays revealed enhanced activities of carboxylesterases (CarE), glutathione S-transferases (GSTs) and cytochrome P450-mediated p-Nitroanisole O-demethylase (PNOD) in resistant strains supporting their role in dimethoate detoxification. This study thus revealed that enhanced activity of detoxifying enzymes viz., CarE, GSTs and PNODs is one of the mechanisms underlying dimethoate resistance in A. gossypii collected from South India. Interestingly, the possibility of negatively correlated cross-resistance to imidacloprid was identified in three OP- resistant strains exhibiting 2.97-, 2.56- and 3.76-fold sensitivity to imidacloprid (a novel neonicotinoid). This indicated that the latter was less affected by the resistance mechanism(s) present.

Design,synthesis,and insecticidal activity of novel terpenoid ester compounds containing bicyclo[2.2.1]heptane against Aphis gossypii Glover

To discover novel and efficient compounds against Aphis gossypii Glover,a series of novel terpene ester derivatives containing the structure of bicyclo[2.2.1]heptane were designed and synthesized using tschimganin as the lead compound.Bioactivity assays showed that most tschimganin analogs exhibited moderate to outstanding insecticidal activity against A.gossypii.In particular,compound 56(LC_(50)=0.28μg mL^(-1)),identified as(1S,2S,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-yl nicotinate,exhibited the best activity,which was significantly superior to that of imidacloprid(LC_(50)=0.54μg mL^(-1))and sulfoxaflor(LC_(50)=0.70μg mL^(-1)).The precise and dependable 3D-QSAR model suggests a promising direction for further design of more active tschimganin-based insecticides.Metabolomics showed that compound 56 disrupted detoxification,amino acid biosynthesis,and energy metabolism and may affect the central nervous system of A.gossypii.The results of this study indicated that tschimganin analogs are a potential new class of green insecticides that can be used for the integrated management of A.gossypii.

Morphological characteristics,developmental dynamics,and gene temporal expressions across various development stages of Aphis gossypii sexual female

Background Aphis gossypii(Hemiptera:Aphididae)is a worldwide polyphagous phloem-feeding agricultural pest,and it can produce offspring by sexual or asexual reproduction.Compared with dozens of generations by parthenogenesis,sexual reproduction is performed in only one generation within one year,and little is known about the sexual reproduction of A.gossypii.In this study,sexual females of A.gossypii were successfully obtained through a previously established induction platform,and the morphological characteristics,developmental dynamics,and temporal gene expression were examined.Subsequently,signaling pathways potentially involved in regulating the growth,development,and reproduction of sexual females were investigated.Results The morphological observation showed that from the 1st instar nymph to adult,sexual females exhibited a gradually deepened body color,an enlarged body size,longer antennae with a blackened end,and obviously protruding cauda(in adulthood).The anatomy found that the ovaries of sexual females developed rapidly from the 2^(nd)instar nymph,and the embedded oocytes matured in adulthood.In addition,time-course transcriptome analysis revealed that gene expression profiles across the development of sexual females fell into 9 clusters with distinct patterns,in which gene expression levels in clusters 1,5,and 8 peaked at the 2^(nd)instar nymphal stage with the largest number of up-regulated genes,suggesting that the 2^(nd)instar nymph was an important ovary development period.Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analysis revealed that a large number of genes in the sexual female adult were enriched in the TGF-beta signaling pathway and Forkhead box O(FoxO)signaling pathway,highlighting their important role in sexual female adult development and reproduction.Conclusion The morphological changes of the sexual female at each developmental stage were revealed for the first time.In addition,time-course transcriptomic analyses suggest genes enriched in the TGF-beta signaling pathway and FoxO signaling pathway probably contribute to regulating the development and oocyte maturation of sexual females.Overall,these findings will facilitate the regulating mechanism research in the growth and development of sexual females by providing candidate genes.

危害枸杞的棉蚜Aphis gossypii Glover

棉蚜Aphis gossypii Glover是一种常见害虫,主要危害次生寄主棉花、玉米、大豆、西瓜、黄瓜、南瓜、茄子、西葫芦、月季、核桃、丁香、金橘等,也危害原生寄主石榴、花椒、木槿和鼠李等。危害枸杞的蚜虫种类多为棉蚜,无翅孤雌蚜体型宽椭圆形,活体淡墨绿色,腹管黑色,

Studies on the Host Biotypes and Its Cause of Cotton Aphidin Nanjing,China

The fitness of cotton aphid, Aphis gossypii Glover, on different host plants was studied. The results showed that the cotton aphid population in Nanjing formed host preference bio-types on cucumber and cotton. The aphids from cotton and cucumber could not inter-transplant successfully between the two host plants. The apterous and alate offspring of stem mother from hibiscus could not survive, reproduce and form population normally when they were transplanted to cucumber and water melon, but they could form normally when transplanted to cotton and muskmelon. There was no significant difference between the stylet length of cotton aphids from cucumber and cotton, so the stylet length was not the cause of the host preference. When the aphids originated on hibiscus were transplanted to cotton, water melon and muskmelon, the stylet could reach host phloem to absorb host plant’s nutrients, but it couldn’t when transplanted to cucumber. Cotton aphid can feed on muskmelon without secretion of water-soluble saliv

Demographic parameters of cotton aphid, Aphis gossypii Glover （Homoptera： Aphididae） on five cotton cultivars

Life table parameters of the cotton aphid, Aphis gossypii Glover, were estimated on five cotton cultivars （‘ Sealand＇ ,‘Siokra＇ ,＇ Vararnin＇ ,‘ Bakhtegan＇ and ‘ Sahel＇ ）. Demographic parameters of the cotton aphid were assessed at 27.5 ± 1 ℃, 65% ＋ 10% RH and a photoperiod of 14：10 （L： D）h. The shortest developmental time for the nymphal stages was 5.5 days on ‘Siokra＇ and the longest was 6.1 days on‘ Sealand＇. The highest offspring per female was 29.6 on ‘Sahel＇ and the lowest was 15.3 on ‘Sealand＇. The rm values varied from 0.272 on ‘Sealand＇ to 0.382 （day^-1） on ‘Varamin＇. Jackknife estimates of the A. gossypii parameters on these cultivars indicated the greatest developmental rate and fecundity on ‘ Varamin＇ and the poorest on ‘ Sealand＇ cultivar.

The impact of allelochemicals on the differential expression of symbiotic bacteria in cotton aphids

Insects have developed a good adaptive mechanism in response to environmental stresses in the long-term evolution. They have developed a helpful metabolism system to resist plant allelochemicals. Insects also harbor different kinds of symbiotic bacteria, which provide them a competitive advantage. Here, using cotton aphid as an example, we investigated the effects of four plant allelochemicals on the differential expression of symbiotic bacteria based on transcriptome data. We also studied the composition of symbiotic bacteria and function on pathway level in three kinds of aphids. We found that the bacteria have a significant role in resisting the plant allelochemicals stress and host plant selection by aphids. These results should be useful to investigate the environmental adaption mechanism of aphids in the view of symbiotic bacteria. These results would offer a new insight for improving strategy of aphids and developing new pest control systems.