Page 50 - Outdoor Oklahoma Magazine Mar-Apr2023

Watchable Wildlife
Eastern Dobsonfly
By Theron Blunck, Education Intern
EASTERN DOBSONFLY

BY THERON BLUNCK, EDUCATION INTERN

It’s a mid-summer Friday evening down rocks in the fast current of streams and riv-
at river’s edge. You and your sweetheart are ers. They appear as a flattened centipede-like
relaxing in the back of your pickup, listen- critter with three pairs of legs on the thorax
ing to the sounds of nature and watching (middle body segment) and four pairs of leglike
the bats come out appendages along their abdomen, each with
in the receding a fuzzy tuft-like gill at its base. The end of the
Although scary looking, twilight. Suddenly abdomen has a pair of leglike hooks that allow

adult male dobsonflies you catch sight of them to hold on to a rock in the fast-moving cur-
rent. Hellgrammites also sport a pair of nubby
the most ferocious
are harmless to people. looking winged mandibles that can also deliver a painful bite.
creature you’ve ever The eastern dobsonfly spends most of its life
It is also thought that seen! Beside you is hiding under stones in the water, feeding on

adult dobsonflies don’t an insect about the other water insects and small fish. After a cou-
size of your hand, ple of years, the larva emerges from the water
even feed during their with large mottled in search of a moist soil area to pupate. This
three- to 10-day lifespan. wings, long whip- is typically under a log, rock, or leaf litter. The
ping antennae, and pupa will grow from eight days up to a month
the biggest set of before emerging as an adult.
pincers you’re certain have ever existed! Adult male dobsonflies vie for the atten-
What is this creature of nightmares you ask? tion of a female by fiercely fluttering their
It’s the eastern dobsonfly (Corydalus cornutus). wings and using those long mandibles to
The eastern dobsonfly is in the family Coryd- attempt to flip over other males in a courtship
alidae, which also includes the fishflies. They are competition. The successful male is allowed
found throughout most of eastern and central to approach the female, which will receive the
North America, including Oklahoma. male after showing a display of aggression.
This insect appears in its adult form as a Eggs are deposited in coin-size masses that
large winged insect that measures up to 5.5 are covered in a hard, chalky substance for
inches long with a wingspan of about 5 inch- protection. Egg masses are usually placed
es. It has a soft, drab-gray, black, or brown on vegetation or objects hanging over or
body. The four wings are covered with white near the water. When the larvae emerge, they
and black splotches. The wings are usually drop into the water, where they begin their
kept folded on its back when at rest. life cycle.
The males and females vary in appearance Although scary looking, adult male dobson-
most prominently by the size and shape of flies are harmless to people. It is also thought
their mandibles (pincers). Males have sick- that adult dobsonflies don’t even feed during
le-shaped mandibles that can measure up their three- to 10-day lifespan. The hellgram-
to 1.6 inches long. Despite their threatening mite, however, spends its time eating, but also
look, these mouth parts are just for show, is a food item for many fish. Many anglers seek
used in courting. out hellgrammites because they are excellent
Female dobsonflies have short, nubbed man- bait. But, the mouth parts that make them
dibles that can be used to deliver a painful bite. fierce predators also make them hard biters, so
Larval dobsonflies, known as hellgrammites, anglers should keep that in mind when collect-
spend most of their lives in the water under ing them as bait.

48 OUTDOOR OKLAHOMA