Discussion in 'Fly Fishing Entomology' started by Grant Richie, Nov 30, 2010.
Aren't hellgrammites an Eastern US bug?
Roger, Roger. Thanks for chiming in. Beetle larva huh?
The larva of a dobsonfly is often referred to as a hellgrammite, and yes, it is only found east of the continental divide. However, the larva of a fishfly is sometimes also referred to as a hellgrammite, as it a close relative (same family, different subfamily). Most flyfishers would be hard-pressed to differentiate a larval dobsonfly from a larval fishfly, and fishflies are found in WA.
helgramite all the way!!!!
Roger, great info as always. Thank you sir. Now I'm going to have to do a bit of research to see if these beetle larvae have a lifecycle period in the aquatic playgrounds that I like to visit. Ed
The Dobsonfly, also known as "The King Bug" for its kingly features and intimidating tusks, is an insect of the subfamily Corydalinae, part of the megalopteran family Corydalidae. The most well-known species is Corydalus cornutus, the Eastern Dobsonfly. This is a long, dark-colored insect found in North and Central America. Their closest relatives are the fishflies.
Female Eastern dobsonfly
Male Eastern dobsonfly
A hellgrammiteBoth male and female dobsonflies can reach lengths up to five inches (12.5 cm), measured from the tips of their pincers to the tips of their four wings. Their wingspans can be twice as long as their body length. The wings are densely lined with intersecting veins. When not in use, the wings are folded along the length of their walkingstick-like bodies. Dobsonflies have segmented antennae similar to ants and wasps.
Though both male and female dobsonflies have sharp mandibles, those of an adult male dobsonfly are actually so big – up to 1 inch (25 mm) – that they are unable to harm humans, as they have such poor leverage that they are incapable of breaking the skin. Their mandibles are used exclusively during mating, where males show them off and grasp the females during copulation. Female dobsonflies, however, retain the short, powerful pincers they had as larvae, so they can inflict painful bites, which can draw blood. Not withstanding the males' inability to inflict harm, when threatened both sexes will raise their heads and spread their jaws menacingly. They are not poisonous, but possess an irritating, foul-smelling anal spray as a last-ditch defense.
Dobsonflies spend most of their life in the larval stage, during which they are called hellgrammites, and are familiar to anglers who like to use the large larvae as bait. Hellgrammites live under rocks at the bottoms of lakes, streams and rivers, and prey on other insect larvae with the short sharp pincers on their heads, with which they can also inflict painful bites on humans. The larvae reach to 2" to 3" in length, with gills all along the sides of their segmented bodies that allow them to breathe underwater. Their gills, primitive nervous systems, and hard, segmented bodies mean that once hooked, hellgrammites can survive for long periods wiggling underwater. In the Appalachians, children catch these for fishing bait as a test of courage, working their fingers into the mud under rocks until a hellgrammite bites, then grabbing the creature with the other hand and throwing it into a jar. A less painful way to catch them is to stretch a mesh net across a narrow point in the stream, forcing the net to the bottom, then have others upstream turn over rocks and disturb the creek bottom, forcing the hellgrammites into the streamflow so they are carried into the net, whence they can be plucked and put into bait buckets.
After a few years of living and growing underwater, the larvae crawl out onto land and pupate. They stay in their cocoons over the winter and emerge only to mate. Upon emerging, they live for only seven days. While not generally believed to eat during their adult stage, some captive female specimens have been observed with their heads burrowed into blackberries.
Adults can generally be found from late spring into the middle of summer, preferring to remain near bodies of water, particularly the ones where they grew up. Once they emerge as adults they mate, deposit their eggs near the water (often on overhanging vegetation), then die. They are primarily nocturnal, and like most aquatic insects, are commonly attracted to bright lights.
Knew it was a Hellgramite from the photo, but this is a good description.
Bug geeks for sure, good job guys.
Nice to hear from you. There are ~2451 species of aquatic beetles found in lakes and streams of N. America. However, the particular beetle larva whose posted photo started this thread is not aquatic, but rather, terrestrial.
Definitely no gills on that critter. There were midges all over the snow and I was kind of curious if he might have been having a midge feast.
Not unlikely, Richie, they are predaceous.