Life Sciences Commons^™

Impact Of Sublethal Exposure To A Pyrethroid-Neonicotinoid Insecticide On Mating, Fecundity And Development In The Bed Bug Cimex Lectularius L. (Hemiptera: Cimicidae), Sydney E. Crawley, Jennifer R. Gordon, Katelyn A. Kowles, Michael F. Potter, Kenneth F. Haynes

Entomology Faculty Publications

Sublethal exposure to an insecticide may alter insect feeding, mating, oviposition, fecundity, development, and many other life history parameters. Such effects may have population-level consequences that are not apparent in traditional dose-mortality evaluations. Earlier, we found that a routinely used combination insecticide that includes a pyrethroid and a neonicotinoid (Temprid^® SC) had deleterious effects on multiple bed bug (Cimex lectularius, L.) behaviors. Here, we demonstrate that sublethal exposure impacts physiology and reproduction as well. We report that sublethal exposure to Temprid SC has variable aberrant effects on bed bugs depending on the strain, including: a reduction in …

Mapk Signaling Pathway Alters Expression Of Midgut Alp And Abcc Genes And Causes Resistance To Bacillus Thuringiensis Cry1ac Toxin In Diamondback Moth, Zhaojiang Guo, Shi Kang, Defeng Chen, Qingjun Wu, Shaoli Wang, Wen Xie, Xun Zhu, Simon W. Baxter, Xuguo Zhou, Juan Luis Jurat-Fuentes, Youjun Zhang

Entomology Faculty Publications

Insecticidal crystal toxins derived from the soil bacterium Bacillus thuringiensis (Bt) are widely used as biopesticide sprays or expressed in transgenic crops to control insect pests. However, large-scale use of Bt has led to field-evolved resistance in several lepidopteran pests. Resistance to Bt Cry1Ac toxin in the diamondback moth, Plutella xylostella (L.), was previously mapped to a multigenic resistance locus (BtR-1). Here, we assembled the 3.15 Mb BtR-1 locus and found high-level resistance to Cry1Ac and Bt biopesticide in four independent P. xylostella strains were all associated with differential expression of a midgut membrane-bound alkaline phosphatase (ALP …

Novel Mutations And Mutation Combinations Of Ryanodine Receptor In A Chlorantraniliprole Resistant Population Of Plutella Xylostella (L.), Lei Guo, Pei Liang, Xuguo Zhou, Xiwu Gao

Entomology Faculty Publications

A previous study documented a glycine to glutamic acid mutation (G4946E) in ryanodine receptor (RyR) was highly correlated to diamide insecticide resistance in field populations of Plutella xylostella (Lepidoptera: Plutellidae). In this study, a field population collected in Yunnan province, China, exhibited a 2128-fold resistance to chlorantraniliprole. Sequence comparison between resistant and susceptible P. xylostella revealed three novel mutations including a glutamic acid to valine substitution (E1338D), a glutamine to leucine substitution (Q4594L) and an isoleucine to methionine substitution (I4790M) in highly conserved regions of RyR. Frequency analysis of all four mutations in this field population showed that the three …

Molecular Cloning And Characterization Of A P-Glycoprotein From The Diamondback Moth, Plutella Xylostella (Lepidoptera: Plutellidae), Lixia Tian, Jiaqiang Yang, Wenjie Hou, Baoyun Xu, Wen Xie, Shaoli Wang, Youjun Zhang, Xuguo Zhou, Qingjun Wu

Entomology Faculty Publications

Macrocyclic lactones such as abamectin and ivermectin constitute an important class of broad-spectrum insecticides. Widespread resistance to synthetic insecticides, including abamectin and ivermectin, poses a serious threat to the management of diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), a major pest of cruciferous plants worldwide. P-glycoprotein (Pgp), a member of the ABC transporter superfamily, plays a crucial role in the removal of amphiphilic xenobiotics, suggesting a mechanism for drug resistance in target organisms. In this study, PxPgp1, a putative Pgp gene from P. xylostella, was cloned and characterized. The open reading frame (ORF) of PxPgp1 consists of 3774 …

Pyrosequencing The Bemisia Tabaci Transcriptome Reveals A Highly Diverse Bacterial Community And A Robust System For Insecticide Resistance, Wen Xie, Qing-Shu Meng, Qing-Jun Wu, Shao-Li Wang, Xin Yang, Ni-Na Yang, Ru-Mei Li, Xiao-Guo Jiao, Hui-Peng Pan, Bai-Ming Liu, Qi Su, Bao-Yun Xu, Song-Nian Hu, Xuguo Zhou, You-Jun Zhang

Entomology Faculty Publications

BACKGROUND: Bemisia tabaci (Gennadius) is a phloem-feeding insect poised to become one of the major insect pests in open field and greenhouse production systems throughout the world. The high level of resistance to insecticides is a main factor that hinders continued use of insecticides for suppression of B. tabaci. Despite its prevalence, little is known about B. tabaci at the genome level. To fill this gap, an invasive B. tabaci B biotype was subjected to pyrosequencing-based transcriptome analysis to identify genes and gene networks putatively involved in various physiological and toxicological processes.

METHODOLOGY AND PRINCIPAL FINDINGS: Using Roche 454 pyrosequencing, …

Rna Interference Of Nadph-Cytochrome P450 Reductase Results In Reduced Insecticide Resistance In The Bed Bug, Cimex Lectularius, Fang Zhu, Sarah Sams, Tim Moural, Kenneth F. Haynes, Michael F. Potter, Subba R. Palli

Entomology Faculty Publications

BACKGROUND: NADPH-cytochrome P450 reductase (CPR) plays a central role in cytochrome P450 action. The genes coding for P450s are not yet fully identified in the bed bug, Cimex lectularius. Hence, we decided to clone cDNA and knockdown the expression of the gene coding for CPR which is suggested to be required for the function of all P450s to determine whether or not P450s are involved in resistance of bed bugs to insecticides.

METHODOLOGY/PRINCIPAL FINDINGS: The full length Cimex lectularius CPR (ClCPR) cDNA was isolated from a deltamethrin resistant bed bug population (CIN-1) using a combined PCR strategy. Bioinformatics and in …

Gene Expression Profiling In The Thiamethoxam Resistant And Susceptible B-Biotype Sweetpotato Whitefly, Bemisia Tabaci, Wen Xie, Xin Yang, Shao-Ii Wang, Qing-Jun Wu, Ni-Na Yang, Ru-Mei Li, Xiao-Guo Jiao, Hui-Peng Pan, Bai-Ming Liu, Yun-Tao Feng, Bao-Yun Xu, Xuguo Zhou, You-Jun Zhang

Entomology Faculty Publications

Thiamethoxam has been used as a major insecticide to control the B-biotype sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae). Due to its excessive use, a high level of resistance to thiamethoxam has developed worldwide over the past several years. To better understand the molecular mechanisms underlying this resistance in B. tabaci, gene profiles between the thiamethoxam-resistant and thiamethoxam-susceptible strains were investigated using the suppression subtractive hybridization (SSH) library approach. A total of 72 and 52 upand down-regulated genes were obtained from the forward and reverse SSH libraries, respectively. These expressed sequence tags (ESTs) belong to several functional categories based …

A Brain-Specific Cytochrome P450 Responsible For The Majority Of Deltamethrin Resistance In The Qtc279 Strain Of Tribolium Castaneum, Fang Zhu, R. Parthasarathy, Hua Bai, Katharina Woithe, Martin Kaussmann, Ralf Nauen, Douglas A. Harrison, Subba R. Palli

Entomology Faculty Publications

Cytochrome P450-mediated detoxification is one of the most important mechanisms involved in insecticide resistance. However, the molecular basis of this mechanism and the physiological functions of P450s associated with insecticide resistance remain largely unknown. Here, we exploited the functional genomics and reverse genetic approaches to identify and characterize a P450 gene responsible for the majority of deltamethrin resistance observed in the QTC279 strain of Tribolium castaneum. We used recently completed whole-genome sequence of T. castaneum to prepare custom microarrays and identified a P450 gene, CYP6BQ9, which showed more than a 200-fold higher expression in the deltamethrin-resistant QTC279 strain when compared …

Co-Up-Regulation Of Three P450 Genes In Response To Permethrin Exposure In Permethrin Resistant House Flies, Musca Domestica, Fang Zhu, Ting Li, Lee Zhang, Nannan Liu

Entomology Faculty Publications

BACKGROUND: Insects may use various biochemical pathways to enable them to tolerate the lethal action of insecticides. For example, increased cytochrome P450 detoxification is known to play an important role in many insect species. Both constitutively increased expression (overexpression) and induction of P450s are thought to be responsible for increased levels of detoxification of insecticides. However, unlike constitutively overexpressed P450 genes, whose expression association with insecticide resistance has been extensively studied, the induction of P450s is less well characterized in insecticide resistance. The current study focuses on the characterization of individual P450 genes that are induced in response to permethrin …