title: Molecular mechanisms of Tetranychus urticae chemical adaptation in hop fields.
abstract: 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.
authors.affiliation: Irrigated Agriculture Research and Extension Center, Washington State University, Prosser, WA 99350, USA.
authors.forename: Tara G
authors.initials: TG
authors.lastname: Piraneo
authors.affiliation: Irrigated Agriculture Research and Extension Center, Washington State University, Prosser, WA 99350, USA.|Department of Entomology, Washington State University, Pullman, WA 99164, USA.
authors.forename: Jon
authors.initials: J
authors.lastname: Bull
authors.affiliation: Department of Entomology, Washington State University, Pullman, WA 99164, USA.
authors.forename: Mariany A
authors.initials: MA
authors.lastname: Morales
authors.affiliation: Department of Entomology, Washington State University, Pullman, WA 99164, USA.
authors.forename: Laura C
authors.initials: LC
authors.lastname: Lavine
authors.affiliation: Irrigated Agriculture Research and Extension Center, Washington State University, Prosser, WA 99350, USA.
authors.forename: Douglas B
authors.initials: DB
authors.lastname: Walsh
authors.affiliation: Irrigated Agriculture Research and Extension Center, Washington State University, Prosser, WA 99350, USA.|Department of Entomology, Washington State University, Pullman, WA 99164, USA.
authors.forename: Fang
authors.initials: F
authors.lastname: Zhu
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D060829:Arthropod Proteins / Q000235:genetics*; D045303:Cytochromes b / Q000235:genetics*; D004351:Drug Resistance / Q000235:genetics*; D020125:Mutation, Missense; D010575:Pesticides; D040102:Tetranychidae / Q000235:genetics*; D061566:Voltage-Gated Sodium Channels / Q000235:genetics*
chemical_list: D060829:Arthropod Proteins; D010575:Pesticides; D061566:Voltage-Gated Sodium Channels; D045303:Cytochromes b