Location: Southern Insect Management ResearchTitle: Insecticide resistance monitoring of tarnished plant bug (Hemiptera: Miridae) populations in the Mid-Southern United States
|CATCHOT, BEVERLY - Mississippi State University|
|GORE, JEFFREY - Mississippi State University|
|KRISHNAN, NATRAJ - Mississippi State University|
|JACKSON, RYAN - Syngenta|
|MUSSER, FRED - Mississippi State University|
Submitted to: Journal of Cotton Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/3/2022
Publication Date: N/A
Interpretive Summary: Tarnished plant bug is a major pest of cotton in the mid-southern U.S. The Mississippi River Delta region is farmed more intensively and annually tends to have higher insect pressure than the Hills region. As a result, more insecticide applications are made on cotton in the Delta region than in the Hills region This study provided new resistance monitoring results for tarnsihed plant bug for 63 populations collected during 2017 to 2019 from two well defined agricultural regions of the mid-southern U.S.: Delta and Hills.
Technical Abstract: Tarnished plant bug, Lygus lineolaris (Palisot de Beauvois) (Hemiptera: Miridae), is the target for multiple insecticide applications in cotton in the mid-southern U.S. Resistance to several insecticide classes has been documented, so monitoring of resistance levels to insecticides currently used is needed before field control failures occur. Several populations were tested to estimate resistance levels for commonly used insecticides during 2017 to 2019. On average, 25 to 40% of populations were determined to be resistant to thiamethoxam, imidacloprid, and/or sulfoxaflor. There were no differences among years in mean imidacloprid and thiamethoxam LC50 values; however, the mean LC50 increased from 2017 to 2019 for sulfoxaflor. No differences in resistance were detected between the two primary agricultural regions of the Mid-South (Hills and Mississippi River Delta) for any of the insecticides. For each insecticide, the range between the most and least susceptible populations was greatest in the Hills region during 2018. Susceptibility to thiamethoxam was the most variable followed by imidacloprid and sulfoxaflor. It is important to continue monitoring for resistance because continued selection pressure is likely to lead to widespread reduced efficacy in the future.