Subject: Bugs swarming at night
Geographic location of the bug: Central Iowa
Time: 08:47 AM EDT
Your letter to the bugman: Hi bug man, we live on a farm in central Iowa. The following bug has been swarming our lights at night and leaving heaping piles of dead bugs on the ground in the morning. What are these things?!
How you want your letter signed: Becky H
Goodness Gracious Becky.
You have a plague of biblical proportions on your hands. Even after cropping your image to a vertical, there appears to be hundreds of thousands of Water Boatmen present. These are Water Boatmen in the family Corixidae, and your individuals look like the one in this BugGuide image from the genus Trichocorixa. Your submission is definite proof of the BugGuide claim: “Adults fly to lights, sometimes in great numbers.” Water Boatmen are aquatic True Bugs and according to BugGuide: “Common in ponds. Also found in birdbaths. A few species live in streams, and others are found in brackish pools along the seashore above the high tidemark.” Their food is listed as: “Algae, detritus, other aquatic organisms (mosquito larvae, brine shrimp).” If this is the first time you have ever experienced this situation, we can only conclude that for some reason, conditions are ripe for a population explosion. Perhaps fertilizer runoff to a nearby pond is causing an algae bloom, providing a food source for millions of Water Boatmen. Since they can also fly, if a pond dries out, the Water Boatmen can migrate to another aquatic habitat.
Thank you for the information! I told my husband they looked like the water bugs in our 1.4 acre pond that is right by our house! We also live 1/4 mile from whitebreast creek. I’m going to attach a video from this morning… biblical proportions is right!
We don’t load many videos to our site, but yours is quite amazing and tells the story way better than the still image. Glad we could assist in the ID. Hopefully this situation will not last very much longer.