title: Impact of insecticides on the invasive Halyomorpha halys (Hemiptera: Pentatomidae): analysis of insecticide lethality.
abstract: The efficacy of 37 insecticide treatments against adult Halyomorpha halys (Stål) was established based on exposure to 18-h old dry insecticide residue in laboratory bioassays. Individual adult H. halys were exposed to an insecticide residue for 4.5 h and then monitored daily for survivorship over a 7-d period. The proportion of dead and moribund insects was used as an estimate of overall insecticide efficacy against H. halys immediately after the exposure period and over the 7-d trial. Among all materials evaluated, 14 insecticides exhibited increasing efficacy, in which the percentage of dead and moribund insects (used as a measure of insecticide efficacy) increased by > 10% after 7 d. By contrast, insecticide efficacy values of eight insecticides declined by > 10% (based on recovery of adults from a moribund state) over the 7-d period with most belonging to the pyrethroid class. In this study, the efficacy value of neonicotinoid, acetamiprid, showed the greatest decline from 93 to 10% over 7 d. A lethality index (scale of 0-100) was developed to compare insecticides based on quantifying the immediate and longer-term effects of insecticide exposure on H. halys. Among all materials evaluated, dimethoate, malathion, bifenthrin, methidathion, endosulfan, methomyl, chlorpyrifos, acephate, fenpropathrin, and permethrin yielded the highest values (> 75) because of a high degree of immediate mortality with very little recovery. Our results provide baseline information regarding potential of candidate insecticides against adult H. halys and highlight the need to consider longer-term effects in establishing overall efficacy ratings against this invasive species.
authors.affiliation: U.S. Department of Agriculture-Agriculture Research Services, Appalachian Fruit Research Station, 2217 Wiltshire Road, Kearneysville, WV 25430-2771, USA. tracy.leskey@ars.usda.gov
authors.forename: Tracy C
authors.initials: TC
authors.lastname: Leskey
authors.forename: Doo-Hyung
authors.initials: DH
authors.lastname: Lee
authors.forename: Brent D
authors.initials: BD
authors.lastname: Short
authors.forename: Starker E
authors.initials: SE
authors.lastname: Wright
mesh_terms: D000818:Animals; D005260:Female; D020062:Heteroptera / Q000187:drug effects*; D007306:Insecticides / Q000633:toxicity*; D058865:Introduced Species; D008297:Male; D010573:Pesticide Residues / Q000633:toxicity*; D013997:Time Factors; D014903:West Virginia
chemical_list: D007306:Insecticides; D010573:Pesticide Residues