AboutEric R. Eaton Expertise I can answer most questions related to wasps, solitary bees, grasshoppers and katydids, beetles, cicadas, and spiders, especially requests to identify "mystery bugs" in North America!
Experience
Past/Present clients Principal author of the "Kaufman Field Guide to Insects of North America" (in bookstores now!), Smithsonian Institution (contract), Cincinnati Zoo (employer), Portland State University (contract), Chase Studio, Inc (employer), Arkansas Museum of Discovery (guest speaker), Krohn Conservatory, Cincinnati (volunteer trainer, guest speaker).
Expert: Eric R. Eaton Date: 7/6/2008 Subject: mystery black fling insect by the thousands on our river bank and house???
Question We came out of our house this morning to find thousands of black flying insects
resting all over our river bank, covering the barks of the trees so they are
completely black and covering the back of our house and our neighbors house.
What are these?They are flying and resting They first appeared this morning.
They look something like a dragonfly.
Answer
Beth:
So they just "fling" themselves around, do they?:-) LOL! I love the typographical errors I get with the questions. I'm a writer first, and entomologist second, so I am really alert to such things....on to your question.
You don't state where on the planet you live (I do get questions from places other than the U.S. and Canada), or what kind of habitat you live in (mountains? forest? desert?), but I think I might still be able to help you.
A mass emergence of some kind of aquatic insect is likely what you have, and I strongly suspect mayflies of the order Ephemeroptera, as they are well-known for astronomical numbers of individuals in some swarms. The good news is that they are harmless to your health. They don't even feed at all, in fact. The better news is they will be gone in a day or two. Mayflies have the shortest lifespan of any adult insect. By contrast, they may live three or more years in the larval stage (often called a 'nymph' or 'naiad') before emerging as adults. Mayflies are also the only insects known to molt as adults! They emerge from the naiad stage as "duns" or "subimagoes," then molt again to become "spinners" or "imagoes.
You can find lots of images of mayflies on the internet, including at websites for fly fishing, since hatches of mayflies mean a prime time to go fly fishing.
Feel free to get back to me if these are definitely NOT the animals you are describing, but then please be prepared with many more details, and/or an image.
