The multicolored Asian ladybug, also known as the harlequin lady beetle or ladybird (or just Harmonia axyridis), carries a fungal parasite in its blood that doesn’t seem to cause it much harm, but is deadly to the native ladybugs of Europe and North America.

That’s why the Asian ladybug has been such a ferocious competitor to native ladybugs, a paper in last week’s issue of the journal Science found. Scientists have long known that where Asian ladybugs are introduced, native ladybugs disappear, but they weren’t sure why. It seemed that the invasive species was out-competing the natives somehow. The new study explains why.

A fungus in the same genus infects honeybees.

Read the article in Science, here. (Subscription or fee required to see the entire article.)
Read the AAAS ScienceShot, here.Here’s the Guardian article, which I ignored at first because it focuses on European ladybugs. (The North American natives are in the same boat.)
Here’s the Los Angeles Times article on the same paper.

Fly away home, indeed.

Photo: ©entomart, just some of the many varieties of the multicolored Asian ladybug