Insect Signs of Fall: Part III

To find insects this time of year, you need go no further than the outer wall of any building.  After a quick walk around the North Branch Nature Center’s building this morning, dozens of insects were found attempting to break in.  There were the usual house and cluster flies, two Western Conifer Seed Bugs, a Boxelder Bug, and several March Flies, but the clear winners were ladybugs with almost 20 clinging to the wall.

Ladybugs are not true “bugs” (they are actually beetles) and only about half are actually ladies.  There are many species of ladybugs, too, although all that we found today were the Multicolored Asian Ladybug (Harmonia axyridis).  This species, which we’ll call MAL for short, was introduced to the North American almost 100 years ago as a biological control for aphids.  

Multicolored Asian Ladybug's can vary greatly in
color and pattern, as seen in this mating pair.

 Today, MAL’s are well established across the continent and have become abundant in some areas.  A decline in native species of ladybugs has been documented in tandem with the establishment of the MAL and other exotic ladybugs.  MAL’s have also been well known for their tendency to enter houses and buildings at the onset of winter, so there’s a good chance that you’ll see one this fall, both outside and in!

By Larry Clarfeld