Trichogramma spp. (Hymenoptera: Trichogrammatidae) as egg parasitoids of Sepedon fuscipennis (Diptera: Sciomyzidae) and other aquatic Diptera

At least 2 species of Trichogramma were found parasitising the eggs of Sepedon fuscipennis hlw. (a sciomyzid that preys on aquatic snails, including Helisoma spp., Physa spp. and Lymnaea spp.) in fresh-water habitats in central New York State. T. julianoi Platner & Oatman parasitised S. fuscipennis and the sciomyzid Elgiva sundewalli Kloet & Hincks. A species near to T. californicum Nagaraja & Nagarkatti parasitised S. fuscipennis, E. sundewalli and Tetanocera spp. Trichogramma julianoi was most active in early and late summer, and the other species of Trichogramma was most active in mid- and late summer. Another undescribed species similar to T. semblidis (Auriv.) occurred in the same habitats but did not parasitise S. fuscipennis; its primary hosts were stratiomyids. The mortality of eggs of S. fuscipennis due to Trichogramma varied over the summer and reached 43.6% in late July and early August. A list of parasites reared from the eggs of insects in at least 10 families in 4 orders is given, and includes Trichogramma and Telenomus in Chrysops spp. and other tabanids.