Natural Enemies of Blackflies and Midges
Isomermis
The genus Isomermis has been described from black flies and midges around the world. Welch (1962) described Isomermis wisconsinensis as a parasite of Simulium vittatum in Wisconsin. Unlike other common mermithids of Simulium found in Southern California, this parasite does not follow the same body plan as the Wisconsin species. The color is the most obvious difference. The newly parasitic, postparsitic, and adult forms are a dark tan or brownish color similar to what Rubzov (1972) described occurring in Isomermis brevis .
Isomermis species
Eggs
Eggs in the early stages of development. Unlike many mermithids, females of this species will begin depositing eggs after maturity, eventhough they are unmated. The eggs of the unmated female will not, however, develop.
Adults Male
Males have short, paired spicules.
Adult Female
Females have an s-shaped vagina with the vulval lips protruding from the body.
Mermithid Page
Last modified 19 December 1999