Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: 1/31/2010
Publication Date: 4/1/2010
Citation: Allen, K.C., Musser, F., Jackson, R.E., Snodgrass, G.L. 2010. Susceptibilities of Tarnished Plant Bug and Stink Bug Nymphs to Various Insecticides. National Cotton Council Beltwide Cotton Conference. pp.1211-1215. In Proc. Beltwide Cotton Conference January 4-7, 2010, New Orleans, LA. Interpretive Summary: The dose of an insecticide required to kill a particular proportion of an insect population is a useful measurement for studying susceptibilities of an insect species to various compounds. Many times only one life stage of an insect is used for the examination of insecticide effectiveness. For some insect pests, insecticides are applied to control both immature and adult stages. Laboratory studies were conducted to examine the susceptibility of various immature stages of the tarnished plant bug and three stink bug species to different insecticides. The dose required to kill 50% of an immature stage was compared to the dose required to kill 50% of the adult stage of the same species. For each insecticide, the estimated dose necessary to kill 50% of the last stage of immature development were at least twice as high as that of adults for the insecticides examined. The effectiveness of an insecticide application for control of tarnished plant bugs and stink bugs may vary depending on the composition of the different life stages present in a given agricultural field.
Technical Abstract: Laboratory experiments were conducted to examine the susceptibility of the nymphal stages and adult stage of the tarnished plant bug to a pyrethroid (permethrin), organophasphate (methamidophos), and neonicotinoid (thiamethoxam) insecticide. The susceptibilities of 5th instar and adult stages of the green, southern green, and redbanded stink bugs were examined using the pyrethroid, bifenthrin and organophosphate, acephate. Insects were individually placed into glass vials coated with various doses of each insecticide and mortality was recorded after three hours for plant bugs and after 24 hours for stink bugs. Three to four replications of each of the first through fifth instar nymphs and adults were assayed with a different cohort of individuals used for each replication. For tarnished plant bugs, estimated LC50’s of the fourth and fifth instar nymphs were generally at least twice as high as that of adults for the insecticides examined, while the first through third instar nymphs were less than that of adults. The LC50’s of the 5th instars of the various stink bug species were also approximately twice as high as adults within a species.