NO. I BLACK FLIES OF GUATEMALA — DALMAT I5I 



with fewer than 150 rows of hooks ; antennae lacking transverse stria- 

 tions ; and rectal scales absent. Simulium (L.) jacobsi appears closest 

 to S. (L.) samboni and S. (L.) hae'tmtopotum but can easily be dis- 

 tinguished from them by the completely dark patterns of the frons- 

 clypeus, the nonpectinate condition of the branches of the cephalic 

 fans, the color patterns on the thorax and abdomen, and the absence 

 of ventral tubercles on the eighth segment of the abdomen. 



Ty/'^.— Larva (2 slides), in collection of the United States National 

 Museum; collected in the Rio Michatoya, Finca El Llano, Palin, 

 Department of Escuintla, Guatemala, June 22, 195 1. 



SIMULIUM (LANEA) SAMBONI Jennings 



Simulium samboni Jennings, Proc. Ent. Soc. Washington, vol. 17, pp. 199-200, 

 1915 (original description, $ and c?).— Fairchild, Ann. Ent. Soc. Amer., 

 vol. 33, No. 4, pp. 704-705, figs. 8, 9, 24, and 31, 1940 (?, c?, and pupa).— 

 Vargas, Rev. Inst. Salubr. Enferm. Trop., vol. 3, No. 3, P- 240, fig. 6, 1942 

 (c? genitalia). 



Simulium (Lanea) samboni Jennings, Vargas and Diaz, Rev. Inst. Salubr. 

 Enferm. Trop., vol. 9, No. 4, p. 343, figs. 60-61, 1948 (larva).— Dalm at, 

 Ann. Ent. Soc. Amer., vol. 44, No. i, pp. 55-57, iQSi (presence and distribu- 

 tion in Guatemala given). 



Male (pi. 23, figs. 40-42). — 2.2 mm. long. 



Head : Holoptic. Eyes dark reddish brown. Antenna 480 ju, long, 

 1 1 -segmented; segment 3>i+2, 3>4+5, 3 twice 11; scape and 

 pedicel light brown, flagellum darkening toward apex. Palpi dark 

 brown to black. Clypeus dark brown, partially white-pruinose. 



Thorax : Mesonotum yellow to orange, with 2 longitudinal 

 wedge-shaped patches of white pruinosity, the bases on the anterior 

 margin, one on either side of the midline, extending somewhat more 

 than one-fourth the way back ; wide band of white pruinosity on the 

 lateral margins ; short, narrow, golden, scalelike hairs over entire 

 mesonotum, more numerous along anterior margin and in prescutellar 

 region, never in packets; short black hairs over entire mesonotum. 

 Humeral angles pale yellow, white-pruinose, with yellow scalelike 

 hairs. Scutellum pale yellow, with some yellow, scalelike hairs and a 

 few long black hairs. Postnotum velvety brown, its midline yellow, 

 with white pruinosity. Pleura pale yellow, with white pruinosity. 

 Stem of halter dark brown, the knob yellow. Wings, 2.2 mm. long 

 and I.I mm. wide; relation of body length to wing, 1:1; Sc pilose 

 along its basal third; Ri completely pilose, its distal half also with 

 spines ; R2+3 pilose except for minute basal section ; Cuo arcuate ; 

 discal cell absent. 



