The multicolored Asian lady beetle has become very numerous in Illinois homes during the past five years or so. The beetle is one quarter inch in diameter and ranges from yellowish to orange to red with or without 19 black spots on the back. They do not reproduce indoors, they use the wall void as a protected area to spend the winter. They reproduce outdoors after they leave your home in the spring.


Thousands of beetles!

Those that emerge into the living area of the home will die from lack of water and starvation. Only those that stay cold in the wall void will survive until spring. We recommend vacuuming up the beetles as you find them indoors and dumping the sweeper bag outdoors. Because they are attracted to lights, leaving one light on in a room and vacuuming them as they come to it can increase your effectiveness. However, you may have to vacuum daily. Insecticides used indoors will not be very effective.

Outdoors, they are attracted to sunlit walls. Planting trees to shade the south and west sides of the house are long-term answers. Caulking cracks and crevices, particularly around window framing, will also reduce the number indoors. Every crack caulked no only keeps out insects, but it also saves energy costs. Masses of the beetles on the walls in the fall can be killed on contact with insecticidal soap. It can be used daily, if necessary.

There are no easy answers to this insect problem.

- Text courtesy of Dr. Phil Nixon, Illinois Natural History Survey

For further information, check out these web sites:

http://www.ars.usda.gov/is/br/lbeetle/index.html

http://ohioline.osu.edu/hse-fact/1030.html

Lady beetles have invaded my house. How do I get rid of them??