Thursday, July 20, 2006

Dobsonfly, male... different view

This is a male Dobsonfly, approximately 4" long. They live 3-4 years in the water in their larvae stage. After a few years of living and growing underwater, the larvae crawl out onto land and pupate. They stay in their coccoons over the winter and emerge only to mate. Upon emerging, in late spring or early summer they live for only a few days. Dobsonflies have large, powerful jaws, and in the case of females, are capable of drawing blood from humans. Though both male and female hellgrammites (larvae) have short, sharp mandibles, those of the male dobsonfly are much bigger than the females' and are unable to harm humans, as they're so long and flexible that they are incapable of breaking the skin. They are used exclusively for grasping the females during mating. Female dobsonflies, however, retain the short, powerful pincers they had as larvae, so they can inflict painful nonvenomous--bites. When threatened, they will raise their heads and spread their pincers menacingly. They also possess an irritating, foul-smelling anal spray, as a last-ditch defense. These pictures of the male were taken in Alder Creek. The Hellgrammites can only survive in clean running water and are a good indicator of the conditions of the water.

Dobsonfly, male