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Ladybugs In Houses

NATURAL HISTORY
The lady beetles seen in huge numbers during the fall, both in and outside homes, are non-native lady beetles (Harmonia axyridis) from Asia. The history of their introduction into this country depends on who you ask. One theory is that they were introduced here in the early 1900's by the USDA to combat aphids on fruit trees, but it is believed that this population did not survive. They were then discovered in Louisiana, prompting the theory that they may be arriving in cargo ships from Asia. A third theory is that they were introduced to reduce aphids in pecan groves. In any case, they are now found in all New England states and apparently are not doing any harm to our native lady beetle species.

IDENTIFICATION
These ladybugs are similar in size to our native species, but their color and patterns are more variable, ranging from yellow to red; and from no spots to up to a dozen spots.

BENEFICIAL INSECTS
They are very beneficial; their larva eat the aphids that harm apple, peach and plum trees, as well as, maple and pine. A report from the USDA's Southeastern Fruit and Nut Tree Research Laboratory has found that in some pecan groves pesticide use has been reduced 50 to 75 percent since these aphid-eaters arrived.

SITUATIONS AND SOLUTIONS

Why are they attracted to houses? In Asia these beetles overwinter in the cracks and crevices of limestone outcroppings and it believed that this is the reason they are attracted to the white trim on houses and, when they manage to get inside, white ceilings.

What options do we have for living with ladybugs?

• Do nothing. If left alone they will soon find their way into the attic, voids in walls, or other out-of-the-way locations, to spend the winter. And, except for a rare warm winter day when a few might be confused and fly around, they won't be seen until spring. When they emerge in the spring all they want to do is get outside and "fly away, fly away," so open windows a couple of inches and let them do just that!
• If they cannot be tolerated, they should be vacumed up rather than squished because they will leave a foul-smelling, yellow stain behind.
• Do not use insectides. Chemicals are dangerous--ladybugs are not!

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