Fishflies are somewhat peculiar-looking, non-pest insects that could be described in one way as small versions of dobsonflies, which are their closest living relatives. But, unlike dobsonflies, the jaws (mandibles) of fishflies are small and not nearly as fierce-looking as those of dobsonflies, and, fishfly males have very feathery antennae, such as the one shown here. Both fishflies and dobsonflies are aquatic insects (their larvae live in water). They both undergo complete metamorphosis and the adults of both are attracted to lights on warm summer nights, including one well-known North America (and Maine) species of fishfly called simply the “summer fishfly” (Chauliodes pectinicornis). Fishflies are considerably larger than mayflies, and the adults may live up to seven days compared to 24 hours or less for mayfly adults. Good fishfly habitat would be in areas near slow-moving water (dobsonflies, by contrast, prefer running streams).
Additional Information and Photos: Fishflies (courtesy of BugGuide.net)