Resistance risk assessment of six pyrethroids and acephate toward the resistant adult tarnished plant bug, Lygus lineolaris

Abstract

Due to rapidly developed resistance, pest management relies less on pyrethroids to control economically damaging infestations of the tarnished plant bug (TPB), Lygus lineolaris (Palisot de Beauvois) in cotton fields of Mississippi. Yet, pyrethroid resistance remains prevalent in TPB populations. This study assessed the resistance levels in adult TPB to six common pyrethroids and acephate. Resistant TBPs were collected from wild host plants in late October after harvest in the Mississippi Delta region of the United States. Based on LC50 values, the field‐resistant TPBs displayed higher resistance to permethrin, esfenvalerate, and bifenthrin (approximately 30 fold) and moderate resistance to λ‐cyhalothrin, β‐cyfluthrin, ζ‐cypermethrin, and acephate (approximately 15 fold). Further investigations showed that the inhibitors of three detoxification enzyme, triphenyl phosphate (TPP), diethyl maleate (DEM), and piperonyl butoxide (PBO) had synergistic effects on permethrin, λ‐cyhalothrin, and bifenthrin in resistant TPBs. Furthermore, elevated esterase, GST, and P450 activities were significantly expressed in field‐resistant TPBs. Additionally, GST and esterase were reduced after 48 h exposure to certain pyrethroids at LC50 dose. The synergistic and biochemical assays consistently indicated that P450 and esterase were involved in pyrethroid detoxification in TPBs. This study provides valuable information for the continued use of pyrethroids and acephate in controlling TPBs in cotton fields in the Mississippi Delta region of the United States.

Microarray and Functional Pathway Analyses Revealed Significantly Elevated Gene Expressions Associated with Metabolic Resistance to Oxamyl (Vydate) in Lygus lineolaris

“…Frequent insecticide exposures are the driving force for the resistance development in TPB populations. Small scale characterizations of a few individual detoxification genes and enzymes (P450s, esterases, and glutathione S-transferases (GST)) provided evidence for associating metabolic detoxifications closely with pyrethroid-, organophosphate-, and neonicotinoid-resistant TPB field populations [ 3 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ]. Large-scale (global) analyses of 6688 transcriptional responses of a field TPB resistant population to the selections with representative insecticides of three classes of conventional insecticides (organophosphate, neonicotinoid, and pyrethroid) provided solid evidences of metabolic detoxification enzymes-mediated insecticide resistance in TPBs, by evolving a particular set of genes (esterases, oxidases, P450s, GSTs), together with a few dehydrogenase, synthase, reductase, and transferase genes in corresponding detoxification pathways [ 15 , 16 , 17 ].…”