Sciomyzids

Marsh or Snail-killing Flies (family Sciomyzidae) are very common around wetlands. According to Flies: The Natural History and Diversity of Diptera by Stephen A. Marshall "most sciomyzids occur in moist to aquatic environments, where they develop as parasitoids or predators of aquatic or semiaquatic snails or sphaeriid clams such as fingernail clams." According to Bugguide.net over two hundred species in twenty genera exist in North America.

The Marsh Flies I most often encounter are of the genus Sepedon. This is a very distinctly-shaped fly, foward-thrusting antennae, a long face and grasshopper-like rear legs. Most often, this fly perches upside-down on grass stems and the stalks of other vegetation near water.

Over the last two days, I've encountered two additional kinds of Marsh Fly. Yesterday, the tiny Pherbellia sp. was observed on a dandelion flower next to a catchment pond. Today, the spot-winged Dictya was observed on a blade of grass along a small, temporary rivulet.

Posted on 23 de abril de 2017, 03:36 AM by scottking