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Multicolored Asian Lady Beetle

Harmonia axyridis

The Multicolored Asian lady beetle, Harmonia axyridis. This species has become quite a nuisance in the United States even though it is a voracious predator.

History: This Multicolored Asian Lady Beetle was intentionally imported from Russia, Japan, Korea, and elsewhere in the Orient and for releases in the United States as part of a Federal effort to naturally control insect pests in trees. With the first releases (1916 and 1960) the beetle did not establish.  The in the 1970s and the early 1980s, tens of thousands of these beetles were intentionally released by the U. S. Department of Agriculture's Agricultural Research Service (USDA-ARS) in an effort to control insect pests that injure trees. All did not go as planned, as many home owners found out.

In their native countries these beetles over winter on cliff faces and crevices, here in the US they have taken to buildings to over winter. They are attracted to light colored houses, especially light-colored walls with a south or southwest exposure. They settle down into the dark cracks to over-winter.  This means in the winter they are likely to crawl into the inside of houses, invading homes becoming an annoyance to the human inhabitants. Recent studies have shown that their attraction is not strictly to white or light colored homes, but more the strong vertical contrasts made in late afternoon, when their urge to migrate is strongest. Homes or structures with vertical columns, dark colored shutters against a light background, or strong vertical shadows simulate trees against a mountainside, resemble their natural hibernation destination in Asia. (study done by Joe Kovach and Margaret Huelsman of Ohio State)

Once in the walls they are more likely to become active on warm winter days. When they are in your home they will not feed or breed but die. They do not do structural damage, nor do they lay eggs indoors.  When indoors they are hard to control, so prevention is important. 

Multicolored Asian lady beetles have also been reported to nibble or "bite" humans. They are not aggressive, but may taste to seek moisture. They will not break the skin or draw blood nor cause health problems.

Do not swat or smash lady beetles. They have yellow body fluids that can stain walls and fabric.

Control: Caulking up cracks and other opening that allowing them into the walls will help.  Inspect the outside of building from top to bottom and screen or seal any openings small enough to admit the beetles. Don't for get the roof lines. If they are inside they can be removed by vacuuming or by use of a black light trap. Want to built a trap? Trapping system for flying insects.

I have heard people recommend everything from bay leaves  or basil in window sills to stuffing cotton balls with camphor essential oil on them in the entry holes.  People even  use Ben Gay around window to repel (Ben Gay has both camphor and menthol) What these products are doing is keeping  the beetles from entering your home, which studies have show camphor and menthol do repel lady beetles.

Multicolored Asian lady beetle

Harmonia axyridis

 

Larva of the 

Multicolored Asian lady beetle

 

This beetle is typically orange-red with or without spots or may only have traces of 4 spots. They all have a black M on the white area just behind the head.

 

 

 

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