2 NEW SPECIES OF STRELKOVIMERMIS (NEMATODA, MERMITHIDAE) AS IMAGICIDAL PARASITES OF CHIRONOMIDS (DIPTERA, CHIRONOMIDAE) IN LAKE ITASCA, MINNESOTA, USA

June 1988-1992 collections of imagos of Chironomus plumosus, Chironomu s tentans, and Chironomus atroviridis from Lake Itasca (Clearwater Cou nty), Minnesota, U.S.A., yielded two new species of post-parasitic mer mithid nematodes in the genus Strelkovimermis. The hemocoelic nematode species from the first two hosts is described as Strelkovimermis itas censis n. sp. and from the third host, Strelkovimermis atroviridis n. sp. A long buccal funnel and an acute posterior terminus separate S. i tascensis from the other seven species in the genus. A rounded posteri or terminus, lack of a neck constriction, vagina with long terminal li mbs, and spicules that lack terminal spines distinguish S. atroviridis . The six previously described species in this genus were reported fro m Russia, Argentina and southwestern Louisiana, U.S.A. S. itascensis r esembles S. singularis most closely, and S. atroviridis most closely r esembles S. viridis. The length of the buccal funnel is suggested as a useful diagnostic characteristic in mermithid nematodes.