It used to be that those cute little orange and black lady bugs only brought smiles and the knowledge that the local aphid population was well under control. More recently, an imposter has arrived from overseas and this little beetle bites. Although they look quite similar to the Lady Beetles that are native to North America, the Multicolored Asian Lady Beetle (Harmonia axyridis) continues to widen its range, and surprise folks with an unexpected pinch.
Plenty of evidence suggests that the Asian Lady Beetle first came to this country on behalf of the USDA’s search for beneficial insects in the teens of the last century, but experts pretty well agree that those small populations of bugs weren’t sufficient to cause the current outbreak. Instead, the new wave of Asian bugs is blamed on a ship that offloaded the stowaways at the port of New Orleans in 1988.
Twenty years later, the invasive insects have made their way to the northern United States and southern Canada and have fanned out to many states east and west of their landing point. Asian Lady Beetles are distinguished by an M-shaped marking on a white background behind their heads (on the thorax), their tendency to move indoors (in droves) for the winter and of course their bite. Asian Lady Beetles do a number on aphids and other soft-bodied arthropods and scientists feel that in time, their population expansion will reach some equilibrium.
Multicolored Lady Beetle Links:
www.ca.uky.edu/entomology/entfacts/ef416.asp
www.ipm.iastate.edu/ipm/iiin/ladybeetles.html
www.ars.usda.gov/is/br/lbeetle/
www.extension.umn.edu/distribution/housingandclothing/M1176.html
www.extension.umn.edu/yardandgarden/ygbriefs/e615ladybeetles.html
wihort.uwex.edu/gardenfacts/X1050.pdf
Comprehensive Lady Beetle Links:
www.nysaes.cornell.edu/ent/biocontrol/predators/ladybintro.html
ohioline.osu.edu/hyg-fact/2000/2002.html
www.ent.iastate.edu/imagegallery/lady/
www.uoguelph.ca/debu/lady/lady-beetles.htm
www.ca.uky.edu/entomology/entfacts/ef105.asp