Chironomus eximius, Johannsen, 1946

Johannse, O. A., 1946, Some New Species Of Nemocerous Diptera From Guam, Insects of Guam II, Honolulu, Hawaii: Bernice P. Bishop Museum, pp. 187-193 : 193

8. Chironomus eximius , new species (fig. 1, l).

Male: head, including basal antenna! segment, brown; flagellum and its hairs paler brown; palpi yellowish. Thorax reddish yellow, including vittae of mesonotum, pleura, metanotum, and sternum; the humeri, scutellum and space between the thoracic vittae pale yellow, whitish pruinose, the scutellum more shining. Anterior abdominal segments pale yellow, with greenish tinge in some specimens, posterior segments darkened; in some cases the abdomen is more uniformly yellowish brown. Legs yellow, extreme tips of tarsal segments darkened. Wings hyaline, more or less milky, the crossvein slightly darkened. Squamae fringed. Halteres yellow, apex of knob dark.

Antennae with 12 segments, the last segment nearly three times as long as segments 2 to 11 combined; frontal tubercles present; palpi as in the preceding species. Pronotal collar complete, with notch anteriorly in the middle. Venation as in the foregoing C. insolens . No tarsal beard; proportions of segments of fore legs, 33: 28: 50: 24: 23: 21: 11; the basitarsal-tibial ratio therefore about 1.75. Fore tibiae with scale, middle and hind tibiae each with two combs, each comb with a short spur; empodium and pulvilli well developed. Hypopygium (fig. 1, l) resembles that of C. dorsalis of Europe, with the superior appendages well developed, bare, somewhat enlarged toward th.e apex. Inferior appendages nearly straight, with the usual curved hairs. Dististyles narrowed apically, with the tuft of hairs on the inner side. Tergal spur slender. Total length 4 mm.; of wing, measured from the humeral crossvein, 2.2 mm.

Piti , July 5, May 2, Swezey and Usinger ; Inarajan , May 7, July 25, Swezey and Usinger ; Sumay Road , June 23, Swezey and Usinger. Holotype in the Cornell University collection; paratypes in the collections of Cornell University and the Experirp.ent Station, Hawaiian Sugar Planters' Association.

Two female specimens collected July 5 and believed to belong here differ from the males in having darker thoracic markings and the brown coloring of the abdomen more extended, fore legs more or less brownish tinged. Other female specimens from other parts of the island have the abdomen a uniform brown, in some cases almost black. The latter closely resemble those of C. insolens in coloring, differing in having a larger leg ratio (1.75).