Submitted to: Pest Management Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/23/2016
Publication Date: 6/27/2016
Citation: Morrison III, W.R., Poling, B.N., Leskey, T.C. 2016. The consequences of sublethal exposure to insecticide on the survivorship and mobility of Halyomorpha halys (Hemiptera: Pentatomidae). Pest Management Science. 73:389-396.
Interpretive Summary: The sublethal effects of insecticides (i.e. those effects that do not cause direct mortality) have not been investigated for the brown marmorated stink bug, Halyomorpha halys. In our current study, we exposed stink bug adults to six of the most effective and commonly used insecticides in orchards for a limited 5-min exposure. Subsequently, we assessed the effect of this sublethal dose on the horizontal and vertical movement of adult stink bugs, as well as their flight capacity in the lab. Over half of the insecticide-treated adults were classified as affected, moribund, or dead, compared to just 6% of the adults treated with a water-only control. Horizontal and flight capacity were decreased by half, while vertical climbing capacity decreased by 4-92%, depending on the insecticide. While brown marmorated stink bug adults showed decreases in mobility and flight behavior, they remained capable of travelling significant distances. This highlights the need for management tactics that take advantage of attractive baits to lure bugs to a particular location for 'attract-and-kill' to guarantee that adults repeatedly contact insecticide-treated material in the field.
Technical Abstract: The direct lethal effects of conventional and organic insecticides have been investigated thoroughly for all life stages of H. halys. However, the sublethal effects of insecticides on the behavior of H. halys has been neglected. In the current study, our aims were to evaluate the impact of a brief 5-min exposure to the five most efficacious insecticides from different chemical classes on the survivorship, horizontal and vertical movement, and flight capacity of adult H. halys in the lab. Over half of the insecticide-treated adults were classified as affected, moribund, or dead, compared with only 6% of the adults in the water-only control. We found that the horizontal movement and flight capacity of adults was halved relative to the control, while the climbing capacity was decreased by 4-92%, depending on the insecticide. While H. halys adults exhibited sublethal decreases in mobility and flight behavior, adults were still able to fly a little less than 0.5 km, as well as walk and climb biologically significant distances. This may ultimately impact the decisions made for choice of pest management tactics for H. halys and favor the use of attractive semiochemicals to guarantee that adults repeatedly contact insecticide-treated material.