They came in swarms and lit on our faces and clothing, pinching us if we got in their way. Millions were trying to crawl into the lodge. On the inside sitting by the stone fireplace an innocent child moved a curtain to discover that “a cast of a thousand” had already made it inside. We later found brown Asian lady bugs hiding in the bedding, on window sills, hanging in corners and blacking out light fixtures.
These were not the sweet little ladybugs that I knew in my childhood but were very un-lady-like bugs that were trying to move in with us. These new intruders (Harmonia axyridis) are native to Asia. I remember ladybugs being red with black spots. These Asian ladybeetles come in many variations of color that range from orange and yellow to brown. They also vary in the number of spots with some having as many as 19 black spots and others with no spots at all. Our native ladybugs migrate for the winter but these un-lady-like Asian cousins stay put and find a winter home.
They prefer light-colored or sunny sides of buildings. Some years the swarms are larger than others. If they make it into your home they can spend the winter balled up in groups resting. They don’t feed in the winter; they live on their little fat reserves just like bears. In the spring they will wake up disperse, mate, lay eggs and then die.
How did this exotic ladybug get to America? Rumor has it that in the late 70’s the U.S. Department of Agriculture released Asian ladybugs as a biological control agent (they eat aphids). For several years after the release these lady beetles could not be found so were assumed to be extinct. In 1988 they re-emerged in strength. Today native ladybugs are endangered. Cornell University has launched a project to determine why our native red ladybugs have disappeared, for more information go to www.lostladybug.org
The sheer number of Asian ladybugs can be a nuisance to the homeowner. These beetles are accidental invaders. This means that they are outdoor insects and only become a problem by wandering indoors during a limited portion of their life cycle. These Asian ladybugs do not sting or carry disease but they do have mandibles so they can pinch or nibble your skin. In large numbers they can produce an odor and they leave a discolored ‘spit’ where they hang out. I’ve also noticed that where they crawl across my windowpanes they leave a yellow-orange substance that is hard to clean. This substance can also stain walls and fabrics.
Things that you can do to make these Asian invaders act more like ladies are:
1) Fix damaged screens. Calk cracks around doors and windows. You may need to also install an insect screen over your attic and exhaust fans.
2) If they make it into the house vacuum them up.
3) Trap them with a light trap, which has baffling so that the beetles can go toward the light source then can’t find their way out.(My sister told me she had seen this product and for me not to waste my money).
This B-grade movie cannot have a happy ending since our native ladybugs have moved to Canada. You can only stay diligent in your fight of this un-lady like guest and hope she doesn’t wake up on a warm winter day to drop into your soup or bomb dive a horrified child or guest.
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