Homeowners aren't too happy when large numbers of multicolored Asian lady beetles come inside in autumn. Even though Harmonia azyridis has served well as an effective biological control against aphids and scale insects since its introduction in 1916, its indoor congregation creates a nuisance. So researchers have been looking at compounds that might repel the beetles. Two compounds—camphor and menthol—that seem to irritate the insects' chemosensory organs have shown the best results so far.
Scientists think that using such repellent vapors could push these beneficial beetles from their overwintering sites. Then the insects might be pulled by pheromone lures into traps and released where they'd perform their biocontrol function.
Eric W. Riddick, USDA-ARS Biological Control and Mass Rearing Research Unit, Mississippi State, Mississippi; phone (662) 320-7382.
"A Push-Pull Answer to Asian Lady Beetles" was published in the August 2001 issue of Agricultural Research magazine.