There are 5,000 recorded species of midges. 2,500 species of Chironomidae are found in North America. Most are non-biting and live in water; some have adapted to a low oxygen environment. Of the 40-50 species of midges that may be inhabiting Straits Pond, a small percentage (4-5%) are non-biting aquatic filter-feeders. Filter feeders form swarms in the adult stage and are a nuisance. Midges have a 4-stage life cycle: egg to larvae to pupae to adult. They inhabit the pond during their larval and pupae stages, primarily existing in the shallow edges of the pond. The first generation historically emerge from the pond as adult midges in late April.
Midge Species in Straits Pond
Past studies identified the species of midge found in Straits Pond as C. Decorus (1953 Mass. Dept. of Public Health Study) or C. Riparius (IEP 1980 Study). During the 1992 Straits Pond study, attempts were made to positively identify the species of Chironomid midge found in Straits Pond by sending specimens of midge larvae to the Museum of Natural History in Washington DC. Communication with Dr. Ashad Ali of the Univ. of Florida and Dr. Joel Margolit of Harvard University tentatively indicate the species may be C. chironomus. The 1994 Straits Pond Study refers to the “species of midge fly known as Chironomous Riparius”, so it appears that final identification of the specific species was made.