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NAME: Asian lady beetle (Harmonia axyridis)
ORIGIN: Northeast Asia
DATE INTRODUCED: 1916, but first populations not found in the U.S. until 1988, in Louisiana
HOW IT GOT HERE: Introduced to control plant-eating aphids and other pests
A cousin of the ladybug, the Asian lady beetle looks a lot like our cute, black-spotted red critters. But these insects, which hit Chicago about five years ago, are downright mean, especially to their North American relatives. “Not only have they been aggressively crowding them out; they’ve been eating them—plus whatever else they can get their jaws on,” says Daniel Summers, the Field Museum’s collection manager for insects. Including humans. (The bugs occasionally bite, but they’re not poisonous.) Unlike most ladybug species, which hibernate by burrowing in leaf litter, Asian ladybugs have the annoying habit of wandering indoors in the wintertime.
THE FIGHT: More a household pest than a serious environmental problem, the beetles are best controlled by spraying pyrethroid insecticides outside buildings.
6 days ago