Ladybugs may start invading

News Column

John Wilson

Extension Educator

October 11, 2013

Prepare for “Invasion of the Ladybug”

I can’t prove that there’s a direct connection, but it seems like ladybugs start invading our house about the time the neighbors start combining their crops. I ‘ve wondered if they were still out in the fields, but are forced to look for another place to stay once the crops were harvested. If that’s the case, we can expect these unwanted guests in the near future.

John Wilson

Although these insects are called a lot of things, some which I can’t repeat here, the real name is the Multicolored Asian Ladybird Beetle. This ladybug is larger than many of our native species. “Multicolored” refers to the tremendous color variations, but the most common color is deep orange. It is a voracious feeder and was introduced several times in the U.S. as a biological control agent for the control of aphids and other insect pests.

The biggest problem is where this insect chooses to overwinter. In its native habitat in Asia, large numbers congregate and overwinter in cracks and crevices within cliff faces. Since cliffs are not common in the Nebraska landscape, the next best things are tall houses!

They are attracted to tall houses that are often all by themselves in the landscape, often near a grove of trees. This sounds a lot like homes on farmsteads and acreages in rural areas. Since this lady beetle feeds on soybean aphid, which also are native to Asia, rural homes are very susceptible, although folks who live in town are not immune to their invasions.

This ladybug species has a number of other undesirable qualities.

•        They secrete a foul-tasting chemical, which makes them unpalatable to their enemies. This secretion can stain fabric and wallpaper.

•        Large infestations have a definite odor.

•        They have been reported to be an asthma trigger in some sensitive individuals.

•        They will bite. It isn’t particularly painful, but it is annoying.

Because these ladybugs congregate in enormous masses, the sheer numbers of these beetles can be very frustrating for homeowners. These tips may be helpful:

First, try to minimize entry points:

•        Locate entry points and seal cracks and crevices with caulk to prevent entry.

•        Make sure window screens and doors are tight-fitting. Use weather stripping if needed.

•        Concentrate initial efforts on the south and west sides of structures.

Once beetles are inside, the following suggestions may be helpful:

•        Do not swat or smash lady beetles. Their body fluids can stain draperies and wall coverings.

•        Using insecticides inside the home will not prevent other beetles from coming inside and has limited effectiveness unless sprayed directly on beetles.

•        Vacuuming lady beetles is as effective as insecticides and is the recommended strategy.

If you are using a vacuum cleaner, these lady beetles get sucked into the interior part of the vacuum cleaner and their secretions will cause the vacuum cleaner to smell every time it is used. To prevent this, put a knee-high nylon stocking into the hose wand to capture the beetles before they are sucked into the vacuum cleaner body. Insert the stocking into a connection joint in the wand so it forms a bag inside the hose and a portion of the stocking folds over the outside of the wand to secure it in place when the wand is put back together. After sucking up the beetles, remove the stocking and dispose of the beetles.

For more information on lady beetle control, contact your local UNL Extension office.