Simulium (Hearlea) nigricorne Dalmat

Figs. 4 L–N.

Simulium (Hearlea) nigricornis Dalmat, 1950: 148–151, Figs. 15–20; 1955: 76, 82, 273–275, Figs. 115, 235–236, 315, 355.

(Diagnosis of female and male derived from Dalmat, 1955).

Female: General coloration unknown. Cibarium with a definite indentation along internal margin. Cerci about 2 times wider than high with curved border, anal lobe with abundant hairs distally; genital fork with median rod thin, elongate.

Male: General coloration unknown. Basistylus with strong prominence basally along internal border; ventral plate with small median carina.

Pupa: (Figs. 4L–N). Cocoon shoe shaped, with reinforced anterior margin; length (basal), 2.9 mm; maximum, 3.6 mm. Frontoclypeus with few platelets. Thorax with numerous granules. Gill extended well beyond anterior margin of cocoon, comprised of 2 subannulated, laterally compressed branches; dorsal branch with distal 3/4 darkened, distended and blunt apically; ventral branch elongate, curved, distally tapered, with small distally digitiform projection. Abdominal tergite X lacking terminal spines.

Larva: unknown.

Material examined: Guatemala: (Dalmat collection, USNM) Chimaltenango, Acatenango, río Laguneta, Fca. Tehuyá, 1 pupa (paratype), 29 March 1949 , Luch; 1 pupa (paratype, cocoon only), 26 February 1949 ; 1 pupa (paratype), 25 September 1949 .

Distribution: Guatemala: Chimaltenango.

Discussion: The presence of two annulate gill branches places S. ayrozai, S. ethelae and S. microbranchium close to S. nigricorne, but the short, wide, distally darkened dorsal branch permits their separation. In two paratype pupae, the darkened apex gill dorsal branch mentioned by Dalmat was not observed.