Green Hands — "Green Hands"
Green Hands
The Column Archive
2000 Columns

2001 Columns:

2002 Columns
2003 Columns
2004 Columns
2005 Columns
2006 columns
2007 columns
What's New
CHC Home
Asian Ladybugs

Published in the six Nashoba Publishing papers on Friday, 9 November 2001

Ladybug, Ladybug, fly away home. When I sang that nursery rhyme as a child, however, I didn't have in mind their making themselves at home in my house!

The Multicolored Asian Ladybeetle was both purposefully and accidentally introduced to North America. Purposefully, because it does a better job than the native ladybug, of eating aphids that attack trees. (Pecan growers in Georgia are grateful.) In addition they both eat aphids on field crops, but the Asian version has no natural enemies here, and so may take over from the native.

It's "multicolored" because its main color can be red, or orange, yellow, or black; there are spots, but their shape, number and color are also highly variable. In the fall, however, it's easy to identify by its behavior. Native ladybugs over-winter individually under bark or in leaf litter, but the Asians cluster together in huge numbers on southwest facing, light-colored vertical surfaces, (especially near trees, their summer habitat), and then look for crevices to winter in. If your house is not very tight, they'll find their way indoors, where they again seek light, and tend to end up at — or inside — the windows.

Ladybugs are indispensable for control of soft-bodied sucking pests: you can buy them for your garden. When I first found some indoors, I enthusiastically transported them to my houseplants. However it's the wrong part of their life cycle; though they're not dormant in a warm house, they don’t hunt in winter. (They will drink a little sugar-water if you offer it; put it in a shallow saucer.)

Indoors even a few seem like a lot — but they don't reproduce in winter either, so they won't increase. They don't damage the house structure or anything in it — unless you disturb them, when they may emit their harmless but smelly, yellow-orange blood onto surfaces it may stain. Some people think they "pinch" but they do not bite or sting, bother pets, or infest food.

They're resistant to many pesticides; the ones that kill them mostly shouldn't be used indoors. And outdoors, ladybugs are needed. If you want them out of the house, vacuum them. (To be kind to the bugs and benefit your garden, you can put a handkerchief a between the hose and the bag, gather them up in it and put them outside.)

Better yet, tighten up your house.

The University of Connecticut has more information

Next Date

© Copyright 2001 Catherine Holmes Clark