Horticulture: April 1997

There is a new bug in town. You probably know that already, it is hard not to notice a few thousand of them in your home. What you may not know is that this is a different Lady Beetle than you have seen before.

According to university sources, this new beetle is named Harmonia Axyridis and is commonly called Harmonia lady beetle or Asian lady beetle. As you might guess, this insect's native range is oriental countries including Japan, China, and Southern Siberia.

Many people around this part of the country are trying to guess how these swarms got here and why. Local rumors abound that the Noble Foundation is responsible, but contrary to this popular belief, no Harmonia lady beetles have ever been released in the state of Oklahoma by the Noble Foundation or anyone else that we know about.

The questions remain--how and why? Lady beetles are beneficial insects, feeding on many soft-bodied insects especially aphids. Aphids are pests of economic importance to many tree fruit and nut growers, including pecan growers.

The Harmonia lady beetle is an arboreal or tree-loving species and since aphids have proven hard to control with pesticides, scientists hope that the new beetle will prove to be an effective ally in combating pests. Harmonia lady beetles have been released several times over the years in attempts to colonize them in the U.S.

These releases date back as far as 1916 when a single attempt was made in California. Entomologists from several states made attempts in the 1960's and 1970's, but apparently none were successful. Releases were made in Byron, Georgia from 1978-1982 by USDA scientists hoping to battle yellow aphids in pecan trees.

Initially, very few were found in the wild, until 1990 when evidence of colonization was reported in Haralson County, Georgia, about one hundred miles from the USDA station in Byron. Since then, the population has exploded across the southeastern states.

There is a down side to these wonder bugs, as many of us can attest to. In the autumn months the beetle swarms to overwintering sites. In Asia this is a limestone or granite cliff. In Oklahoma and Texas it usually means your attic or crawlspace where the beetles huddle together as long as it remains cool. However, if they warm up, they may remain active in your home all winter.

Since lady beetles are beneficial insects, there are no insecticides labeled for use on them. Some household sprays and aerosols are effective but the best recommendation for removing unwanted beetles from your home is to vacuum the pests......I mean beneficial insects.