Acute Exposure to Imidacloprid Impairs Walking Behavior of Eocanthecona furcellata (Hemiptera: Pentatomidae)

Imidacloprid, one of the neonicotinoid pesticides, is widely used in various types of farmlands globally, causing negative effects on beneficial insects. The stink bug Eocanthecona furcellata (Wolff) (Hemiptera: Pentatomidae) is an effective generalist predator that provides natural control of Lepidoptera, Coleoptera, and other insect pests. Walking behavior is crucial for these predators; however, the effects of imidacloprid on their walking, and thus searching, behavior remain unknown. We measured walking behavior by using a locomotion compensator to assess the effects of imidacloprid. Acute exposure to imidacloprid significantly reduced the mean walking speed of nymphs (30.6–51.9% depending on instar), adult females (52.0%), and adult males (40.5%). Walking time also was reduced by exposure to imidacloprid in nymphs (27.1–40.5%), adult females (48.2%), and adult males (36.0%), whereas walking distance was reduced in nymphs (8.4–19.8%), adult females (25.2%), and adult males (15.0%). These results reveal that imidacloprid impairs the walking behavior of stink bugs, emphasizing the need to consider the negative effects of neonicotinoid pesticides on the pest control efficacy of natural enemy insects.