Impact of insecticide residue exposure on the invasive pest, Halyomorpha halys (Hemiptera: Pentatomidae): analysis of adult mobility.

Twenty eight insecticides were evaluated in the laboratory to characterize the impact of specific compounds on locomotory behavior and mobility of adult Halyomorpha halys (Stål) (Hemiptera: Pentatomidae). Horizontal distance and angular velocity were measured for individuals exposed to dry insecticide residue for 4.5 h to evaluate how quickly and intensely a given insecticide induced changes in motor activities in no-choice glass arenas. Eight out of nine pyrethroid insecticides induced uncoordinated and irregular movement within 10 min after exposure to insecticides. After 1.5 h, most adults were incapacitated. By contrast, there was no immediate stimulation when H. halys were exposed to organophosphate residues. After 1.5 h, four out of seven organophosphates resulted in increased horizontal distance moved and angular velocity indicating irregular walking paths by exposed adults. Carbamate and neonicotinoid insecticides produced fairly similar patterns with virtually no stimulation in horizontal distance moved or angular velocity, except for imidacloprid and thiacloprid. Neither endosulfan (organochlorine) nor indoxacarb (oxadiazine) affected the horizontal movement of H. halys. Vertical distance climbed by adult H. halys was measured immediately after the 4.5-h insecticide exposure period and at 7 d. In general, adults that survived until day 7 were able to climb vertical distances similar to those in the control. In particular, this result was observed for seven out of nine pyrethroid materials that incapacitated all adults after the 4.5-h exposure period. Mobility changes of adult H. halys are discussed in the context of enhancing integrated pest management programs.