Freak Ladybug Emergence this Weekend

You know, being an entomologist, I usually don't notice or maybe pay too much attention to the insects in my own backyard. I feel like the public gets more of the strange insect explosions and incidences than I do. But this weekend - it actually happened to me! We had a huge explosion of ladybugs congregating all over our garage.

There were literally hundreds of ladybugs congregating on the side of our home that faces the morning sun! When I got to work this morning, low and behold, many of you had experienced the same thing.

Here's what probably happened. During winter ladybugs will nest under the eaves of houses, little cracks and crevices, and other nice, tight, hiding places. When we had a day of warm, sunny weather, those ladybugs probably emerged from those hiding places to take advantage of the warm weather. They were congregating in the sunlight because it's warmer. You may have also noticed that they congregated fairly close together - this is because insect communicate by using chemicals called pheromones, which they 'smell'. They attract one another to the same area using an aggregation pheromone (also explains why you may randomly see many, many insects clumped together in one location - someone found a great spot, and they are sharing the news).

The wet and dark weather was back today and we are expected to have another week of cold weather, so don't expect to see those ladybugs come out again until we have another warm and sunny day. Next time we do - check out the sunlit side of your home and see if the ladybugs used your house to hide through the winter!


Unknown said…
Cool! We sometimes have ladybugs all over the crown molding in my daughter's room. She carried one in tonight, bringing it to me and it seems that the two black "underwings" have gotten stuck extended. Is this something that the ladybug can fix or did she get handled too rough by my daughter?
Molly Keck said…
The ladybug is completely fine! Beetles have soft, membranous wings underneath their hard wings (called elytra). The hard wings protect the soft wings, which are used for flight. The extra hard body is one of the many reasons beetles are so successful. But, you see that on ladybugs every now and then. It was probably either flying and hadn't pulled its wings fully up yet, or startled and had them out a little and ready to take flight. Ladybugs and other beetles are really tough, and I bet the body would get squashed before the wings would every be damaged!

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