Chironomus insolens Johannse, 1946, new species

7. Chironomus insolens, new species (fig. 1, k).

Male: head and thorax, including halteres and scutellum, yellow; mouth parts, basal antenna! segment, thoracic vittae, metanotum, and sternum, brown; median thoracic vitta divided by a fine line. Abdomen dark brown, hairs pale. Legs, including coxae, yellow; tarsal segments, beyond the first, somewhat infuscated. Pronotum complete, notched anteriorly in the center. Wings hyaline, crossvein slightly darkened; third branch of the radius and the media end about equidistant from the apex of the wing; cubitus forks very slightly distad of the crossvein. Squamae fringed. Antennae and fore tarsi broken off. Frontal tubercles present. Fore tibiae terminating in a blunt scale, middle and hind tibiae each with a comb, each.comb with a short spur; pulvilli and empodium well developed. Basal segment of palpus short, second and third more than twice as long as the first, fourth half again as long as the third. Hypopygium rather small (fig. 1, k) claspers short, dististyle oval, not attenuated apically, with numerous short hairs on inner surface instead of the usual longish hair tuft near apex; superior appendages slender, bare, somewhat curved, ending nearly opposite apex of basistyle; inferior appendages reaching almost to apex of dististyle, cylindrical, nearly straight, and provided with the usual long curved hairs. Tergal spur with deep keel, sharply bent downward toward apex, the free part broad and very short. Length 3 mm.; wing 1.9 mm.

Female: two defective specimens believed to belong here, in general like the male in coloring, but with the abdomen still darker. Intermediate antenna! segments fusiform with short necks. Basitarsal-tibial ratio of fore legs, 1.65.

Piti, May 23, Swezey.

Holotype in the Cornell University collection.

This species falls in group B of the subgenus Chironomus as defined by Edwards (1929), but differs from the members of the three series of this group in the form of the hypopygium, the dististyle lacking the tuft of stout, longish hairs at the tip on the inner side characteristic of series 1, and in having well-developed, bare superior appendages and distinct frontal tubercles, differing in this respect from series 3 (Xenochironomus).