Entomology (Study of Bugs)/Insect ID inquiry


Don\'t know what this is
Don't know what this i  
I was told that this book bug was found yesterday afternoon/evening in Wisconsin. It didn't fly at first, I believe it was on the ground, but later flew away after the person in the picture picked it up. I was told that no one has seen a hug like that before.


Thanks for including the image with your question.

The image depicts an adult male Eastern Dobsonfly, Corydalus cornutus .  Females have more "normal" jaws, but they can draw blood with them.  Males are rather clumsy with their oversized jaws.

The larvae of this species are aquatic, living under stones in fast-flowing streams and rivers, and are known as "hellgrammites," prized as fishing bait.

The adult insects are attracted to lights at night, which is where most people see them.  Here's more about them:


Thanks again for being curious and sharing your discovery!


Entomology (Study of Bugs)

All Answers

Answers by Expert:

Ask Experts


Eric R. Eaton


I answer insect and spider identification questions ONLY. Attach images if possible. No "what bit me?", "what do I feed this bug in captivity?", or science fair project questions please. NO TECHNICAL QUESTIONS ABOUT INSECT PHYSIOLOGY.


Principal author, Kaufman Field Guide to Insects of North America. Professional entomologist employed previously at University of Massachusetts, Chase Studio, Inc., and Cincinnati Zoo; contract work for West Virginia Department of Natural Resources, Smithsonian Institution, and Portland (Oregon) State University.

Author, Kaufman Field Guide to Insects of North America, Missouri Conservationist magazine, Ranger Rick, Birds & Blooms, Timeline (journal of the Ohio Historical Society). I have contributed to several books as well.

Oregon State University, undergraduate major in entomology, did not receive degree.

Awards and Honors
One of the top 50 experts in all categories for AllExperts.com, 2009.

Past/Present Clients
Principal author of the Kaufman Field Guide to Insects of North America, Smithsonian Institution (contract), Cincinnati Zoo (employer), Portland State University (contract), Chase Studio, Inc (employer), Arkansas Museum of Discovery (guest speaker). Currently seeking speaking engagements, leadership roles at nature festivals, workshops, and ecotours.

©2016 About.com. All rights reserved.