A: The ladybug you mentioned is probably the multicolored Asian lady beetle Harmonia axyridis Pallas, which was introduced from Asia both purposefully for classical biological control of arthropod pests and accidentally into the United States many times during the twentieth century. It finally became established and quickly spread over the entire United States sometime in the late 1980’s and early 1990’s.
They should not be mistaken for another introduced ladybug from Europe, the http://www.nysaes.cornell.edu/ent/biocontrol/predators/ladybintro.htm, Coccinella septempunctata Linnaeus, which is often found feeding on the same insect hosts and plants.
The H. axyridis lady beetle is orange in color and may or may not be spotted. H. axyridis is a voracious predator of arthropod pests such as aphids, mites, thrips, scale and Lepidoptera eggs. As a predator, it is beneficial for most of the year and has contributed to a decrease in pesticide use. Both H. axyridis larvae and adults feed on pests and quickly build up to large numbers locally (10-20 thousand have been found in homes). However, unlike other ladybugs in the U.S., H. axyridis is attracted to light colored dwellings and other manmade objects which it uses as overwintering sites. The ladybugs often return to the same buildings year after year.
Once the ladybugs are inside a building there are several options for removal. The best option is to purchase a black light trap and use it in rooms where ladybugs are observed as soon as they are seen. When operated at night the light traps are very effective. Use of a vacuum cleaner or other cleaning tools that handle the beetles roughly, while effective, will result in production of the defensive compound by the ladybugs with its unwanted side effects as previously described.
Despite their overwintering behavior, H. axyridis are very valuable as natural enemies of many insect pests and should be tolerated and conserved when possible. This information was taken from a publication by the Department of Entomology & Nematology and the Department of Plant Industry.
0
