December 2024 Kids Corner
from the Gale River Cooperative Preschool
Attack of the Ladybugs!
In this Kids Corner you’ll:
Learn about an invasive ladybug look-alike species in New Hampshire
Learn how you can practice identifying native vs invasive ‘ladybugs’ by participating in a citizen science project.
Have you seen beetles like this inside your house, school, or other buildings this fall? When the weather gets cold some buildings get flooded with these little visitors. They’re doing exactly what you might think-looking for a warm place to spend the winter.
BUT, they aren’t WHO you might think! The beetles that invade homes in the fall and winter are not New Hampshire’s native ladybugs, but an invasive species called the Harlequin ladybird (also known as Harmonia axyridis, the Asian lady beetle, or multicolored Asian lady beetle.)
Harlequin beetles are native to Japan, and there's some debate about how the population in New England today came to the United States. Some believe that they were brought over on cargo ships from Asia by accident. Others believe that they come from populations introduced by the USDA for pest control on commercial farms.
Like native ladybugs, Harlequin beetles like to eat aphids, which are a common pest of commercial crops. Unfortunately, Harlequin beetles have a bigger appetite than native ladybugs. Native ladybugs can eat up to 5,000 aphids in their lifetime, but Harlequin beetles eat way more! Even worse for native ladybugs, Harlequin beetles carry a parasite that doesn’t harm them, but kills ladybugs!
These days it is hard to find a native ladybug. Almost every ladybug you find in New Hampshire is likely to be some type of Harlequin beetle! The good news is that these small invaders don’t eat wood or damage the homes they move into during the winter (aside from being a little stinky) and they’ll leave in the spring. They also don’t sting, but they can bite if you handle them for too long!
While invasive species are generally talked about in a negative way because of their impact on local ecosystems, the reason that these insects invade homes in the fall is a bit endearing. In their native home in Japan, Harlequin beetles fly up to the sides of mountains to warm themselves on sunny cliffs in the winter. Scientists aren’t sure, but some believe that the south side (the sunny side) of light colored homes is the closest thing they can find to their native winter habitat. That may be why they tend to invade light colored buildings, and why we often find them on second or third story windows. They may just be looking for a warm cozy cliff and found your house instead!
Stewardship Tidbit
While Harlequin Lady Beetles may come indoors looking for warmth in the fall, native ladybugs survive the winter by tucking into leaf litter on the ground. Leaving a little bit of “mess” in your yard or garden in the form of fallen leaves and plant debris provides a safe habitat for insects during the cold months; insects that will benefit your garden come spring!
Your Turn!
You can help scientists learn more about why native ladybug populations have declined so much in recent years! Scientists at Cornell University want your help with their Lost Ladybug Project!
The Lost Ladybug Project is a citizen science project that tracks ladybug populations across the United States. (Citizen science is a type of scientific study that uses data and input from the general public. This allows scientists to gather lots more data than they would be able to on their own, and allows lots of people to be involved in ongoing research.)
You can visit the project website at http://www.lostladybug.org/. Here you can get lots of great information about ladybugs and Harlequin beetles, track populations over time, and upload your own photos to be used in the study! When you upload photos of any ladybug you find to the site, you’re helping scientists figure out which type of ladybugs or lady beetles live where. A photo of a native ladybug is an especially exciting piece of data to share! Time for a ladybug hunt!
Here’s a quick guide to telling Harlequin beetles and ladybugs apart:
Sources:
https://www.treehugger.com/you-can-help-save-ladybugs-4863431
https://www.nhpr.org/environment/2021-02-19/ask-sam-what-are-all-these-ladybugs-doing-in-my-house
https://extension.umn.edu/nuisance-insects/multicolored-asian-lady-beetles#where-they-live-1126811
