Invasion of the Asian Lady Bugs

By George Giltner, Advanced Master Gardner, Beauregard Parish

On a recent camping trip in East Texas, my 6 year-old granddaughter noticed an abundance of orange colored lady bugs.  Some were solid orange while others had the typical lady bug black spots over their wing covers.  However they are commonly called the “Multicolored Asian Lady Beetles”, Harmonia axyridis, which includes a color range from red to a yellowish orange.  They can be identified from endemic species of lady bugs by their “white cheeks” or the white “M or W” behind their head.

These foreign lady bugs from Asia (China, Japan, Russia, and Korea) were introduced back in the 1960’s in southern and eastern states to help control crop pests like aphids and scales. In the 1990’s they were well established, and even had massive population aggregations that invaded the fall warmth of buildings. 

They tend to accumulate on the sunny southwest sides of buildings with light-dark features in the afternoon when the temperatures are in the 60’s.  Then they seek warm cavities to overwinter.  This is when they are a problem.  The beetles emit a stink- bug acrid odor.  Also they can stain walls and drapes with yellow secretions when they are disturbed.  Preventive measures are to seal and caulk entry points into buildings.

Other human problems are allergic reactions, asthma, eye irritations, and a pinprick bite when handling.  On the industrial scale, wine makers have big issues with the beetles mixed in with grapes to destroy good wine flavor. 

On the beneficial side, pecan trees, roses, soybeans, corn, and alfalfa crops, are aided with the lady bug feeding on pests.

Annual lady beetle invasions will probably be forthcoming in our area, since our camping trip was nearby at Rusk, Texas.  Also when we arrived home several Asian lady bugs were observed on the shop floor, indicating their transport to DeRidder was a success. Vacuuming and pest sealing are your best bets.  However when it warms up in Spring, the Asian lady bugs will head back to the forests and fields to munch mainly on aphids.