Submitted to: Annals of the Entomological Society of America
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/13/2000
Publication Date: N/A
Interpretive Summary: Recently, the multicolored Asian lady beetle has become a nuisance pest due to the propensity of adults to enter houses (through cracks and crevices on the exterior) in the fall season in search for places to pass the winter. At other times of the year, these lady beetles are important predators of insect pests, which infest trees and crop plants. We conducted experiments sto determine if plant-derived chemicals (monoterpenoids) would effectively repel adults. Camphor and menthol were effective repellants that modified the behavior of this beetle. We report, for the first time, the potential for using more environmentally friendly, biorational chemicals for repelling this beetle from houses. The results of this research is of use to pest management professionals and homeowners.
Technical Abstract: Bioassays were conducted to prevent the multicolored Asian lady beetle, Harmonia axyridis Pallas, from overwintering in buildings. We discovered that certain monoterpenoids elicited avoidance in adults toward treated filter paper within a Petri dish bioassay at 1.0 mg/cm squared. Camphor and menthol were the most effective of the monoterpenoids tested. Y-tube olfactometer bioassays revealed that beetles spent significantly more time (within 10 min oberservation periods) in the arm not containing camphor or menthol (100 ug, 1000 ug) in comparison to the untreated control arm. Another olfactometer bioassay revealed that significantly more beetles remained in the arm not containing camphor or menthol (142 ug) in comparison to the untreated arm (within 45 min observation periods). When camphor (9.4% emulsified concentrate) was sprayed onto crevices on the exterior of a building through which beetles were entering, 100% of approaching beetles were repelled for the duration of the tests (0.5 h, 2 replicates). In another field experiment, significantly fewer H. axyridis were captured in traps containing camphor versus un-baited control traps. Research is continuing to develop a protocol for repelling nuisance beetle aggregations and conserving the beetles for biological control applications.