It’s that time of year in Wisconsin. We’ve been hearing from students and visitors to the library: What’s up with all those ladybugs hanging out at the library?
So what are they?
“Those” ladybugs are called multicolored Asian lady beetles, otherwise known as Harmonia axyridis. They’re slightly different than the cute red ones we often see, but they belong to the same family of small beetles (Coccinellidae). The multicolored Asian lady beetles are more orange colored: appropriate for their appearance around Halloween. Some people say they bite. Most find them annoying.
In autumn, they often congregate in warm, sunny places near buildings (like the library) as they prepare for hibernation during winter.
How did they get here?
Some researchers state the bugs inadvertently made their way to the United States from Asia via ocean-going vessels and then spread throughout the country. Other researchers point to their repeated use as a biological agent in some parts of the U.S. to help control the aphid population. Multicolored Asian lady beetles have only been reported in large numbers in Wisconsin since the mid 1990s.
Want to find our more? Check these links below:
Sources:
Multicolored Asian Lady Beetle – Wisconsin Department of Natural Resources
University of Wisconsin Garden Facts: Multicolored Asian Lady Beetle – University of Wisconsin Extension
Multi-colored Asian Ladybeetle – The Wisconsin Gardener
The Multicolored Asian Lady Beetle, Harmonia axyridis: A Review of Its Biology, Uses in Biological Control, and Non-Target Impacts – Journal of Insect Science