Asian lady beetles, Digi Mart USA News: Asian lady beetles were introduced to the United States about a century ago to control crop pests such as aphids, but the insects have since become a nuisance, especially in colder months when they enter homes to overwinter.
According to a Digi Mart USA News summary of a publisher article, mint-family plants and their oils are a suggested non-pesticide option for deterring the beetles. The article notes that menthol, a key compound in plants such as spearmint, peppermint and pennyroyal, is widely available as an essential oil.
The article cites a USDA report and experiments published in the Annals of the Entomological Society of America. According to that account, the vapors of menthol irritate the beetles’ sensory organs, and beetles spent significantly more time on untreated surfaces than on surfaces treated with menthol or camphor.
The article suggests first sealing potential entry points with caulk or mesh screens and observing where the beetles fly in. Exterior doorways and window frames can then be sprayed with water mixed with several drops of peppermint essential oil.
For beetles already indoors, the article suggests placing cotton balls treated with peppermint, spearmint or another mint oil on windowsill corners, and replacing them regularly. It also suggests camphor oil as an additional option.
These are suggestions from the publisher article, and the publisher article itself states the information was not independently verified.
