|Eastern Dobsonfly- fcps.edu|
Diptera have one set of wings while their second set of would-have-been wings have evolved into small antennae-like balancing structures called halteres. Dobsonflies are in the Megaloptera order which includes fishflies and alderflies. All of these have four wings although you wouldn't know it from the usual pictures as they generally have them tucked tightly on their back.
These are Eastern Dobsonflies, Corydalus cornutus. The male is a fearsome looking beast with long threatening jaws nearly half the length of its body. Their threatening appearance makes one shy away from picking it up. Actually the jaws are rather weak, used only for clasping a willing female to stay with him a little longer. Measuring 2.25" long, it has an almost prehistoric appearance.
Adults only live 7 days and do not eat. They live several years in the aquatic larval stage called hellgrammites. They are a favored bait for fishermen although with increasing pollution they are harder to find in recent years.
Videos are available at wn.com/DobsonFly and extensive scientific information is at tolweb.org/Corydalus.