Fang (Rose) Zhu | Washington State University (original) (raw)

Papers by Fang (Rose) Zhu

The adaptation of herbivorous insects to their host plants is hypothesized to be intimately assoc... more The adaptation of herbivorous insects to their host plants is hypothesized to be intimately associated with their ubiquitous development of resistance to synthetic pesticides. However, not much is known about the mechanisms underlying the relationship between detoxification of plant toxins and synthetic pesticides. To address this knowledge gap, we used specialist pest Colorado potato beetle (CPB) and its host plant, potato, as a model system. Next-generation sequencing (454 pyrosequencing) was performed to reveal the CPB transcriptome. Differential expression patterns of cytochrome P450 complement (CYPome) were analyzed between the susceptible (S) and imidacloprid resistant (R) beetles. We also evaluated the global transcriptome repertoire of CPB CYPome in response to the challenge by potato leaf allelochemicals and imidacloprid. The results showed that more than half (51.2%) of the CBP cytochrome P450 monooxygenases (P450s) that are up-regulated in the R strain are also induced by both host plant toxins and pesticide in a tissue-specific manner. These data suggest that xenobiotic adaptation in this specialist herbivore is through up-regulation of multiple P450s that are potentially involved in detoxifying both pesticide and plant allelochemicals. The adaptation of herbivorous arthropod pests to their host plants is hypothesized to be intimately connected with the ubiquitous development of pesticides resistance in agricultural environment 1–3. However, the molecular mechanisms underlying these connections are still not well known. Many synthetic pesticides resemble or are even derived from plant allelochemicals (e.g. pyrethroids, neonicotinoids), hence, it is likely that the strategies utilized by herbivore pests to surmount a defense to plant toxins and pesticides are very similar 3–6. These strategies include avoidance behavior, a reduction in penetration, an increase in excretion, sequestration and detoxification, and target-site insensitivity 7,8. In different insect systems, these strategies independently or simultaneously contribute to adaptation to plant toxins and/or pesticides. Among these, metabolic detoxification through cytochrome P450s, glutathione S-transferases (GSTs,) uridine diphosphate-glycosyl transferases (UGTs) and carboxyl-esterases (COEs) have been considered as the most dominant cross-resistance mechanisms linking host plant toxins adaptation with pesticide resistance 7,9–11. Herbivorous arthropods are conventionally classified into two categories, generalists (polyphagous) and specialists (monophagous and oligophagous) 12. The generalists feed on more than one plant family, whereas the specialists only consume one or a few closely related plant taxa within one botanical family. Since generalists encounter a wide range of plant toxins in their diet, it is often assumed that generalists likely possess a greater capacity to detoxify plant allelochemicals than specialists 13 , which in turn partially impacts the development of broad pesticide resistance 3. While specialist herbivores tend to have highly efficient detoxification mechanisms fine-tuning their adaptation to a limited spectrum of host plants defense 13. A recent study on a generalist, two-spotted spider mite, revealed that the transcriptional profiles of tomato-adapted mites resembled those of multi-pesticide-resistant populations. The adaptation to tomato increased the resistance to a few unrelated pesticide classes 3. Additionally, a study on the generalist cotton bollworm showed that plant allelochemicals-induced

The bed bug, Cimex lectularius, has re-established itself as a ubiquitous human ectoparasite thro... more The bed bug, Cimex lectularius, has re-established itself as a ubiquitous human ectoparasite throughout much of the world during the past two decades. This global resurgence is likely linked to increased international travel and commerce in addition to widespread insecticide resistance. Analyses of the C. lectularius sequenced genome (650 Mb) and 14,220 predicted protein-coding genes provide a comprehensive representation of genes that are linked to traumatic insemination, a reduced chemosensory repertoire of genes related to obligate hematophagy, host–symbiont interactions, and several mechanisms of insecticide resistance. In addition, we document the presence of multiple putative lateral gene transfer events. Genome sequencing and annotation establish a solid foundation for future research on mechanisms of insecticide resistance, human–bed bug and symbiont–bed bug associations, and unique features of bed bug biology that contribute to the unprecedented success of C. lectularius as a human ectoparasite.

The increased urbanization of a growing global population makes imperative the development of sus... more The increased urbanization of a growing global population makes imperative the development of sustainable integrated pest management (IPM) strategies for urban pest control. This emphasizes pests that are closely associated with the health and wellbeing of humans and domesticated animals. Concurrently there are regulatory requirements enforced to minimize inadvertent exposures to insecticides in the urban environment. Development of insecticide resistance management (IRM) strategies in urban ecosystems involves understanding the status and mechanisms of insecticide resistance and reducing insecticide selection pressure by combining multiple chemical and non-chemical approaches. In this review, we will focus on the commonly used insecticides and molecular and physiological mechanisms underlying insecticide resistance in six major urban insect pests: house fly, German cockroach, mosquitoes, red flour beetle, bed bugs and head louse. We will also discuss several strategies that may prove promising for future urban IPM programs.

The two-spotted spider mite, Tetranychus urticae Koch is a major pest that feeds on >1,100 plant ... more The two-spotted spider mite, Tetranychus urticae Koch is a major pest that feeds on >1,100 plant species. Many perennial crops including hop (Humulus lupulus) are routinely plagued by T. urticae infestations. Hop is a specialty crop in Pacific Northwest states, where 99% of all U.S. hops are produced. To suppress T. urticae, growers often apply various acaricides. Unfortunately T. urticae has been documented to quickly develop resistance to these acaricides which directly cause control failures. Here, we investigated resistance ratios and distribution of multiple resistance-associated mutations in field collected T. urticae samples compared with a susceptible population. Our research revealed that a mutation in the cytochrome b gene (G126S) in 35% tested T. urticae populations and a mutation in the voltage-gated sodium channel gene (F1538I) in 66.7% populations may contribute resistance to bifenazate and bifenthrin, respectively. No mutations were detected in Glutamate-gated chloride channel subunits tested, suggesting target site insensitivity may not be important in our hop T. urticae resistance to abamectin. However, P450-mediated detoxification was observed and is a putative mechanism for abamectin resistance. Molecular mechanisms of T. urticae chemical adaptation in hopyards is imperative new information that will help growers develop effective and sustainable management strategies.

Entomology now is a diversified science discipline, deviating considerably from the incorporated ... more Entomology now is a diversified science discipline, deviating considerably from the incorporated principles of Molecular biology, Genetics and Biochemistry. It has provided necessary tools for transferring and evaluating genetic characteristics not only for a host of insects, but also for related host plants. The molecular approaches have enabled the study of physiologically vital proteins/enzymes and sensillar-neural complexes that are involved in pheromonal studies. The knowledge is vital to devise safe and specific agents for disrupting insect life cycles, thus increasing the efficiency of efforts to manage agricultural pests and disease vectors. This chapter analyzes the impact of new technologies that allow study of molecular events at the single cell level, and highlights the need of modern insect biological research on insect systems.

Insecticide resistance is a major challenge for effective and sustainable Integrated Pest Managem... more Insecticide resistance is a major challenge for effective and sustainable Integrated Pest Management (IPM). Recent advances in genomic and post-genomic approaches not only dramatically improve our understanding of new mechanisms with regard to insecticide resistance but also provide potential tactics to manage pest populations. In this review, we focus on the latest insights on using RNA interference (RNAi) in combination with existing strategies to investigate molecular
mechanisms underlying insect adaptation to insecticides. Importantly, we outline the potential for RNAi as a new alternative for pest control.

Insect Biochemistry and Molecular Biology, Jun 2014

Juvenile hormone (JH) plays important roles in regulation of many physiological processes includi... more Juvenile hormone (JH) plays important roles in regulation of many physiological processes including development, reproduction and metabolism in insects. However, the molecular mechanisms of JH signaling pathway are not completely understood. To elucidate the molecular mechanisms of JH regu- lation of Krüppel homolog 1 gene (Kr-h1) in Aedes aegypti, we employed JH-sensitive Aag-2 cells developed from the embryos of this insect. In Aag-2 cells, AaKr-h1 gene is induced by nanomolar con- centration of JH III, its expression peaked at 1.5 h after treatment with JH III. RNAi studies showed that JH induction of this gene requires the presence of Ae. aegypti methoprene-tolerant (AaMet). A conserved 13 nucleotide JH response element (JHRE, TGCCTCC ACGTGC) containing canonical E box motif (underlined) identiﬁed in the promoter of AaKr-h1 is required for JH induction of this gene. Critical nucleotides in the JHRE required for JH action were identiﬁed by employing mutagenesis and reporter assays. Reporter assays also showed that basic helix loop helix (bHLH) domain of AaMet is required for JH induction of AaKr-h1. 5' rapid ampliﬁcation of cDNA ends method identiﬁed two isoforms of AaKr-h1, AaKr-h1a and AaKr-h1b, the expression of both isoforms is induced by JH III, but AaKr-h1a is the predominant isoform in both Aag-2 cells and Ae. aegypti larvae.

International Journal of Biological Sciences, Feb 2014

While trade-offs between flight capability and reproduction is a common phenomenon in wing dimorp... more While trade-offs between flight capability and reproduction is a common phenomenon in wing dimorphic insects, the molecular basis is largely unknown. In this study, we examined the tran- scriptomic differences between winged and wingless morphs of cotton aphids, Aphis gossypii, using a tag-based digital gene expression (DGE) approach. Ultra high-throughput Illumina sequencing generated 5.30 and 5.39 million raw tags, respectively, from winged and wingless A. gossypii DGE libraries. We identified 1,663 differentially expressed transcripts, among which 58 were highly expressed in the winged A. gossypii, whereas 1,605 expressed significantly higher in the wingless morphs. Bioinformatics tools, including Gene Ontology, Cluster of Orthologous Groups, eu- Karyotic Orthologous Groups and Kyoto Encyclopedia of Genes and Genomes pathways, were used to functionally annotate these transcripts. In addition, 20 differentially expressed transcripts detected by DGE were validated by the quantitative real-time PCR. Comparative transcriptomic analysis of sedentary (wingless) and migratory (winged) A. gossyii not only advances our under- standing of the trade-offs in wing dimorphic insects, but also provides a candidate molecular target for the genetic control of this agricultural insect pest.

Scientific Reports, Mar 14, 2013

Recent advances in genomic and post-genomic technologies have facilitated a genome-wide analysis ... more Recent advances in genomic and post-genomic technologies have facilitated a genome-wide analysis of the insecticide resistance-associated genes in insects. Through bed bug, Cimex lectularius transcriptome analysis, we identified 14 molecular markers associated with pyrethroid resistance. Our studies revealed that most of the resistance-associated genes functioning in diverse mechanisms are expressed in the epidermal layer of the integument, which could prevent or slow down the toxin from reaching the target sites on nerve cells, where an additional layer of resistance (kdr) is possible. This strategy evolved in bed bugs is based on their unique morphological, physiological and behavioral characteristics and has not been reported in any other insect species. RNA interference-aided knockdown of resistance associated genes showed the relative contribution of each mechanism towards overall resistance development. Understanding the complexity of adaptive strategies employed by bed bugs will help in designing the most effective and sustainable bed bug control methods.

BMC Genomics, Mar 14, 2013

"Background: The functional and evolutionary diversification of insect cytochrome P450s (CYPs) sh... more "Background: The functional and evolutionary diversification of insect cytochrome P450s (CYPs) shaped the success of insects. CYPs constitute one of the largest and oldest gene superfamilies that are found in virtually all aerobic organisms. Because of the availability of whole genome sequence and well functioning RNA interference (RNAi),
the red flour beetle, Tribolium castaneum serves as an ideal insect model for conducting functional genomics studies. Although several T. castaneum CYPs had been functionally investigated in our previous studies, the roles of the majority of CYPs remain largely unknown. Here, we comprehensively analyzed the phylogenetic relationship of all
T. castaneum CYPs with genes in other insect species, investigated the CYP6BQ gene cluster organization, function and evolution, as well as examined the mitochondrial CYPs gene expression patterns and intron-exon organization.
Results: A total 143 CYPs were identified and classified into 26 families and 59 subfamilies. The phylogenetic trees of CYPs among insects across taxa provided evolutionary insight for the genetic distance and function. The percentage of singleton (33.3%) in T. castaneum CYPs is much less than those in Drosophila melanogaster (52.5%) and Bombyx mori (51.2%). Most members in the largest CYP6BQ gene cluster may make contribution to deltamethrin resistance in QTC279 strain. T. castaneum genome encodes nine mitochondrial CYPs, among them CYP12H1 is only expressed in the final instar larval stage. The intron-exon organizations of these mitochondrial CYPs are highly diverse.
Conclusion: Our studies provide a platform to understand the evolution and functions of T. castaneum CYP gene superfamily which will help reveal the strategies employed by insects to cope with their environment."

PLoS One, 2012

Background: NADPH-cytochrome P450 reductase (CPR) plays a central role in cytochrome P450 action.... more 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 silico modeling were employed to identify three conserved binding domains (FMN, FAD, NADP), a FAD binding motif, and the catalytic residues. The critical amino acids involved in FMN, FAD, NADP binding and their putative functions were also analyzed. No signal peptide but a membrane anchor domain with 21 amino acids which facilitates the localization of ClCPR on the endoplasmic reticulum was identified in ClCPR protein. Phylogenetic analysis showed that ClCPR is closer to the CPR from the body louse, Pediculus humanus corporis than to the CPRs from the other insect species studied. The ClCPR gene was ubiquitously expressed in all tissues tested but showed an increase in expression as immature stages develop into adults. We exploited the traumatic insemination mechanism of bed bugs to inject dsRNA and successfully knockdown the expression of the gene coding for ClCPR. Suppression of the ClCPR expression increased susceptibility to deltamethrin in resistant populations but not in the susceptible population of bed bugs.

Journal of Insect Physiology, 2012

Nineteen canonical and two Knirps-like family nuclear receptors (NRs) were identiﬁed in the genom... more Nineteen canonical and two Knirps-like family nuclear receptors (NRs) were identiﬁed in the genome of Tribolium castaneum. The current study was conducted to identify NRs involved in regulation of male reproduction. RNA interference (RNAi)-aided knockdown in the expression of genes coding for all 21 NRs showed that reduction in the levels of 11 NRs (E75, E78, FTZ-F1, HR38, HR4, Knirps-like, HNF4, Tail- less, HR51, Dsf and HR39) in the male beetles caused more than 50% reduction in the eggs laid by the female beetles mated with RNAi male beetles. Among these 11 NRs that are required for male reproduc- tion, knockdown in the expression of genes coding for E78 and HR39 in the male beetles resulted in a reduction in the number of sperm produced and transferred to the female when compared to the sperms produced and transferred by the control male beetles injected with bacterial malE dsRNA. In contrast, knockdown in the expression of genes coding for E75 and HR38 caused a reduction in the size of male accessory glands (MAG), the amount of protein produced by the MAG and the expression of genes coding for accessory gland proteins. These data suggest that NRs such as E78 and HR39 regulate sperm produc- tion and their transfer to the females and the other NRs such as E75 and HR38 regulate the development of MAG and the production of accessory gland proteins

Insect cytochrome P450s are known to play an important role in detoxifying insecticides and plant... more Insect cytochrome P450s are known to play an important role in
detoxifying insecticides and plant toxins, resulting in the development of resistance to insecticides and facilitating the adaptation of insects to their plant hosts. Insect P450s are associated with enhanced metabolic detoxification of
insecticides in insects, as evidenced by the increased levels of P450 proteins and P450 activities that result from constitutively transcriptional overexpression of P450 genes in insecticide resistant insects, and some insect P450 genes can be induced by exogenous and endogenous compounds. Both constitutively
increased expression (overexpression) and induction of P450s are thought to be responsible for increased levels of detoxification of insecticides. This chapter reviews strategies for the isolation of cytochrome P450s from house flies and the characterization of their possible importance in insecticide resistance.

The Journal of Biological Chemistry, 2011

Background: Juvenile hormone (JH) and nutrition signals regulate vitellogenin (Vg) synthesis in i... more Background: Juvenile hormone (JH) and nutrition signals regulate vitellogenin (Vg) synthesis in insects.
Results: Expression of genes coding for insulin-like peptides, insulin receptor, Akt, and FOXO is required for transduction of JH and nutrition signals.
Conclusion: JH and nutritional signals function through insulin-like peptide signaling pathway.
Significance: These studies illustrate the complex nature of endocrine regulation of reproduction.

Pest Management Science, 2011

BACKGROUND: RNA interference (RNAi) is a breakthrough technology for conducting functional genomi... more BACKGROUND: RNA interference (RNAi) is a breakthrough technology for conducting functional genomics studies and also as
a potential tool for crop protection against insect pests. Themajor challenge for efficient pest control using RNAi in the field is
the development of efficient and reliablemethods for production and delivery of double-stranded RNA (dsRNA). In this paper,
the potential of feeding dsRNA expressed in bacteria or synthesized in vitro to manage populations of Colorado potato beetle,
Leptinotarsa decemlineata (Say) (CPB), was investigated.
RESULTS: Feeding RNAi successfully triggered the silencing of all five target genes tested and caused significantmortality and
reduced body weight gain in the treated beetles. This study provides the first example of an effective RNAi response in insects
after feeding dsRNA produced in bacteria.
CONCLUSION: These results suggest that the efficient induction of RNAi using bacteria to deliver dsRNA is a possible method
formanagement of CPB. This could be also a promising bioassay approach for genome-wide screens to identify effective target
genes for use as novel RNAi-based insecticides.

BMC Genomics, 2011

Background: The G protein-coupled receptors (GPCRs) belong to the largest superfamily of integral... more Background: The G protein-coupled receptors (GPCRs) belong to the largest superfamily of integral cell membrane proteins and play crucial roles in physiological processes including behavior, development and reproduction.
Because of their broad and diverse roles in cellular signaling, GPCRs are the therapeutic targets for many prescription drugs. However, there is no commercial pesticide targeting insect GPCRs. In this study, we employed functional genomics methods and used the red flour beetle, Tribolium castaneum, as a model system to study the physiological roles of GPCRs during the larval growth, molting and metamorphosis.
Results: A total of 111 non-sensory GPCRs were identified in the T. castaneum genome. Thirty-nine of them were not reported previously. Large-scale RNA interference (RNAi) screen was used to study the function of all these GPCRs during immature stages. Double-stranded RNA (dsRNA)-mediated knockdown in the expression of genes coding for eight GPCRs caused severe developmental arrest and ecdysis failure (with more than 90% mortality after dsRNA injection). These GPCRs include dopamine-2 like receptor (TC007490/D2R) and latrophilin receptor (TC001872/Cirl). The majority of larvae injected with TC007490/D2R dsRNA died during larval stage prior to entering pupal stage, suggesting that this GPCR is essential for larval growth and development.
Conclusions: The results from our study revealed the physiological roles of some GPCRs in T. castaneum. These findings could help in development of novel pesticides targeting these GPCRs.

PNAS, Apr 2010

Cytochrome P450-mediated detoxiﬁcation is one of the most important mechanisms involved in insect... more Cytochrome P450-mediated detoxiﬁcation is one of the most important mechanisms involved in insecticide resistance. How- ever, 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 with its ex- pression in the deltamethrin-susceptible Lab-S strain. Functional studies using both double-strand RNA (dsRNA)-mediated knock- down in the expression of CYP6BQ9 and transgenic expression of CYP6BQ9 in Drosophila melanogaster showed that CYP6BQ9 confers deltamethrin resistance. Furthermore, CYP6BQ9 enzyme expressed in baculovirus metabolizes deltamethrin to 4-hydroxy deltamethrin. Strikingly, we also found that unlike many P450 genes involved in insecticide resistance that were reported pre- viously, CYP6BQ9 is predominantly expressed in the brain, a part of the central nervous system (CNS) containing voltage-gated sodium channels targeted by deltamethrin. Taken together, the current studies on the brain-speciﬁc insect P450 involved in delta- methrin resistance shed new light on the understanding of the molecular basis and evolution of insecticide resistance.

Archives of Insect Biochemistry and Physiology, 2010

We previously reported high deltamethrin resistance in bed bugs, Cimex lectularius, collected fro... more We previously reported high deltamethrin resistance in bed bugs, Cimex lectularius, collected from multiple areas of the United States (Romero et al., 2007). Recently, two mutations, the Valine to Leucine mutation (V419L) and the Leucine to Isoleucine mutation (L925I) in voltage- gated sodium channel a-subunit gene, had been identified to be responsible for knockdown resistance (kdr) to deltamethrin in bed bugs collected from New York (Yoon et al., 2008). The current study was undertaken to investigate the distribution of these two kdr mutations in 110 bed bug populations collected in the United States. Out of the 17 bed bug populations that were assayed for deltamethrin susceptibility, two resistant populations collected in the Cincinnati area and three deltamethrin-susceptible lab colonies showed neither of the two reported mutations (haplotype A). The remaining 12 populations contained L925I or both V419L and L925I mutations in voltage-gated sodium channel a-subunit gene (haplotypes B&C). In 93 populations that were not assayed for deltamethrin susceptibility, 12 contained neither of the two mutations (haplotype A) and 81 contained L925I or V419L or both mutations (haplotypes B-D). Thus, 88% of the bed bug populations collected showed target-site mutations. These data suggest that deltamethrin resistance conferred by target-site insensitivity of sodium channel is widely spread in bed bug populations across the United States.

Gene, Feb 20, 2007

The transcriptional regulation of gene expression is a primary means by which insects adapt to a ... more The transcriptional regulation of gene expression is a primary means by which insects adapt to a changing environment. The evolution of insecticide resistance is conferred through mechanisms, typically requiring the interaction of multiple genes. Consequently, the characterization of gene regulation and interactions in resistance is fundamental for achieving an understanding of the complex processes responsible for resistance. cDNA macroarray technology offers a promising new approach for investigating the complicated processes responsible for resistance development by revealing the interrelations of all of the elements in a resistant system simultaneously. In the current study, we compared the gene expression profiles of resistant and susceptible Culex quinquefasciatus mosquitoes, using a combination of subtractive PCR hybridization and cDNA microarray technique. By screening of 1500 cDNA clones from a resistant-susceptible mosquito subtractive library, we identified a set of genes with up-regulated expression in insecticide resistant Culex mosquitoes through transcriptional profiling compared to those in susceptible mosquitoes. These genes are vital for cellular and molecular metabolism, signal transduction, vesicular and molecular transport, protein biosynthesis, ubiquitination, and neuronal survival, but most have not previously been implicated in insecticide resistance. Functional studies of resistance-associated up-regulated genes should shed new light on both the molecular basis of resistance and the regulatory pathways that lead to it.

Insect Biochemistry and Molecular Biology, Jun 2014

International Journal of Biological Sciences, Feb 2014

Scientific Reports, Mar 14, 2013

BMC Genomics, Mar 14, 2013

PLoS One, 2012

Journal of Insect Physiology, 2012

The Journal of Biological Chemistry, 2011

Pest Management Science, 2011

BMC Genomics, 2011

PNAS, Apr 2010

Archives of Insect Biochemistry and Physiology, 2010

Gene, Feb 20, 2007

The two-spotted spider mite, Tetranychus urticae Koch is a world-wide agriculture super pest that... more The two-spotted spider mite, Tetranychus urticae Koch is a world-wide agriculture super pest that can feed on > 1,100 plant species in more than 140 families. In West Coast, some perennial specialty crops, such as hops are plagued by spider mite infestations. Hop (Humulus lupulus), as a flavoring and stability agent in beer, is an economically important crop valued at $163 million in Washington State, where produces 90% of all U.S. hops. In most situations, hops growers apply inexpensive disruptive pesticides to suppress the spider mite populations. Unfortunately spider mites have been shown to quickly develop tolerance and/or resistance to these chemicals which directly caused control failure. In order to design the most effective and sustainable spider mite management tactics, our long-term goal is revealing the molecular mechanisms underlying the chemical adaptation of T. urticae in hops field. To achieve our long-term goal, we collected about 100 T. urticae field samples across Washington State during hops seasons 2013-2014. Recent molecular studies revealed a number of target site mutations and detoxification associate genes that involved in the chemical adaptation to common used acaricides, such as Abamectin, Bifenazate, and Pyrethroids. We investigated the distribution of these multiple mutations and relative expression of detoxification related genes in field collected samples compared with the susceptible T. urticae population. The unique mechanisms underpinning the chemical adaptation of Tetranychus urticae in hops field will be discussed.