Location: Southern Insect Management ResearchTitle: Patterns of tarnished plant bug (Heteroptera: Miridae) resistance to pyrethroid insecticides in the lower Mississippi Delta for 2008-2015: Linkage to pyrethroid use and cotton insect management
Submitted to: Journal of Insect Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/30/2018
Publication Date: 3/15/2018
Citation: Parys, K.A., Luttrell, R.G., Snodgrass, G.L., Portilla, M. 2018. Patterns of tarnished plant bug (Heteroptera: Miridae) resistance to pyrethroid insecticides in the lower Mississippi Delta for 2008-2015: Linkage to pyrethroid use and cotton insect management. Journal of Insect Science. 18(2):29. https://doi.org/10.1093/jisesa/iey015.
Interpretive Summary: Tarnished plant bug populations were screened for potential resistance to pyrethroid insecticides using a diagnostic dose bioassay from 2008 through 2015. The data collected adds to historical data about the susceptibility of this pest, and continue to show resistant populations. Resistance levels in field populations are variable, indicating that these bioassays continue to be relevant to the needs of farmers. Data on pyrethroid resistance levels is also used in exploratory analysis using estimates of cotton losses and control costs from the National Cotton Council. The number of plant bugs that died when exposed to the diagnostic dose of permethrin, a pyrethroid, was negatively associated with the amount of pyrethroids applied per acre of harvested cropland.
Technical Abstract: Populations of tarnished plant bug (Lygus lineolaris (Palisot de Beauvois)) from the Lower Mississippi Delta regions of Arkansas, Louisiana and Mississippi were evaluated from 2008 through 2015 for susceptibility to pyrethroid insecticides using a diagnostic-dose assay with permethrin developed by Snodgrass and Scott (1999). Resulting data add to the longitudinal compilation of pyrethroid susceptibility data carefully tracked in this pest since 1994, and provide continuing evidence of high frequencies of pyrethroid resistance in tarnished plant bug populations. Resistance levels are variable and some populations remain susceptible suggesting practical value in the continued use of the diagnostic-dose assays prior to imitation of pyrethroid treatments. Recent studies with dose-response models suggest that levels of pyrethroid resistance in some populations may still be evolving with some populations requiring higher doses to reach comparable levels of control observed ten years ago. Concerns for excessive use of multiple classes of insecticides and possible selection for tarnished plant bugs with metabolic resistance mechanisms capable of detoxifying available insecticide chemistries warrant continued efforts to manage resistance in this important crop pest. Associations among measured pyrethroid resistance levels, published data on annual use of pyrethroid insecticides, and annual estimates of cotton insect losses and control costs by the National Cotton Council were explored and summarized for the eight years of this investigation. Mortality of tarnished plant bugs at the diagnostic-dose of permethrin was negatively correlated with kg of pyrethroids applied per acre of harvested cropland.