Resistance monitoring to four insecticides and mechanisms of resistance in Lygus lineolaris Palisot de Beauvois (Hemiptera: Miridae) populations of southeastern USA cotton

Abstract

BACKGROUND: Economically damaging infestations of the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), have become more frequent in Virginia and North Carolina cotton since 2013 and 2010, respectively. Foliar insecticide use has increased dramatically in response. Efficacy data (LC 50) are needed to evaluate L. lineolaris susceptibility and resistance levels (RR 50) to commonly used and recommended insecticides for managing this pest in the southeastern USA. RESULTS: Elevated resistance levels to acephate and bifenthrin were measured in L. lineolaris populations collected from wild and cultivated hosts in Virginia, North Carolina and northern Alabama when compared to a susceptible laboratory population. High levels of bifenthrin resistance were observed in 2018 and 2019. Mixed-function oxidase and esterase (EST) inhibitors, piperonyl butoxide and S,S,S-Tributyl phosphotrithioate, respectively, had a synergistic effect on bifenthrin with resistant populations of L. lineolaris. Bifenthrin-resistant L. lineolaris populations expressed elevated levels of cytochrome P450 (CYP 450) monooxygenase and general EST activity. Results suggest that insecticide resistance is present in some locations and that CYP 450 and EST activity in L. lineolaris contribute to pyrethroid resistance in the southeastern USA. CONCLUSIONS: Results can serve as a baseline for continued monitoring of L. lineolaris insecticide resistance and inform insecticide resistance management strategies that help southeastern USA cotton producers to minimize inputs and slow resistance development.

Reduced insecticide susceptibility of the wheat aphid Sitobion miscanthi after infection by the secondary bacterial symbiont Hamiltonella defensa

“…AChE and GST are known targets of many organophosphate‐ and carbamate‐based insecticides 40–42 . Upregulation of CYP450 genes and esterase (EST) genes in imidacloprid‐resistant insects has been reported, most extensively in Lygus lineolaris 43–45 . Additionally, there is emerging evidence that insect endosymbionts can mediate insecticide resistance by increasing the detoxification and degradation abilities of host insects 46–48 .…”

“…[40][41][42] Upregulation of CYP450 genes and esterase (EST) genes in imidacloprid-resistant insects has been reported, most extensively in Lygus lineolaris. [43][44][45] Additionally, there is emerging evidence that insect endosymbionts can mediate insecticide resistance by increasing the detoxification and degradation abilities of host insects. [46][47][48] The symbiont Burkholderia in the broad-headed bug Riptortus clavatus can degrade the insecticide fenitrothion, 14 and bacteria isolated from the guts of moths can easily degrade the insecticides indoxacarb and acephate.…”

Current scenario of RNAi‐based hemipteran control

“…Numerous studies have shown a trend of increasing insect resistance against conventional chemical insecticides 51,52 . Presently, no studies have been published regarding the evolution of resistance in hemipteran pests toward RNAi; however, evolution of resistance to dsRNA in the coleopteran insect, Western corn rootworm, D. virgifera virgifera , recently has been shown experimentally 53 …”

Biology, Ecology, and Pest Management of the Tarnished Plant Bug, Lygus lineolaris (Palisot de Beauvois) in Southern Row Crops

“…Overproduction of esterases causes elevation of metabolic detoxification activity, which leads to the increased organophosphate resistance levels observed in L. lineolaris . Recent studies by Dorman et al [ 107 ] reported elevated levels of cytochrome P450 monooxygenase and general esterase (EST) activity in bifenthrin-resistant L. lineolaris populations. Jones et al [ 93 ] reported antagonistic effects when bifenthrin and acephate mixtures were used together.…”

“…Since this last review, few new insecticides have been labeled in the United States for L. lineolaris control in cotton, apart from additional neonicotinoids such as thiamethoxam (Centric, Syngenta Crop Protection, Greensboro, NC, USA). Moreover, since the last review, resistance to neonicotinoids has been reported [ 86 , 107 ]. The benzoylphenylurea insecticide novaluron (Diamond ® , ADAMA, Raleigh, NC, USA) was registered for commercial use in cotton in 2004 ( , accessed on 20 June 2021).…”