Related Experiment Video
Updated: May 27, 2026
Bioassays for Monitoring Insecticide Resistance
Published on: December 30, 2010
Pyrethroid insecticide tolerance in bean leaf beetle, Cerotoma trifurcata, in the Mississippi Delta
Fred R Musser1, Katherine S Knighten, John F Smith
1Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Mississippi State, MS, USA. fm61@msstate.edu
Background:
Pyrethroid insecticides have historically been effective for controlling bean leaf beetles in soybeans. Perceived field efficacy in the Mississippi Delta region has been lower over the past several years. Laboratory and field data were collected to determine whether there has been a reduction in pyrethroid insecticide susceptibility.
Results:
Laboratory and field data both confirmed that control of bean leaf beetles with pyrethroid insecticides is poorer in the Delta regions of Mississippi and Louisiana than in all other regions tested. However, it was not possible to show that this reduced susceptibility changed over time. Furthermore, insect movement appeared to make insecticide susceptibility regional, so that localized insecticide applications had little impact on the susceptibility of successive generations.
Conclusion:
Lack of field control owing to low efficacy of pyrethroid insecticides against bean leaf beetle populations in the Delta region should be expected. Selection pressure on a regional basis may further decrease efficacy. Carbamate insecticides generally still provide high levels of control.
