NO. I BLACK FLIES OF GUATEMALA — DALMAT I3I 



SIMULIUM (LANEA) COLVINI Dalmat 



Sinmlimn (Lanea) colvini Dalmat, Ann. Ent. Soc. Amer., vol. 45, No. 2, pp. 344- 

 347, figs. 8-14, 1952(b) (original description, <S, ?, and pupa). 



Male (pi. 23, figs. 28-30). — 2.4 mm. long. 



Head : Holoptic. Eyes light reddish brown. Antenna 430 fx long, 

 ii-segmented, slightly tapering; segment 3 = 1+2, 3>4 + 5, 3>ii; 

 scape and pedicel yellow, flagellum light brown. Palpi black. Clypeus 

 black with white priiinosity and with few, irregularly distributed, 

 short black hairs. 



Thorax : Mesonotum yellow to orange ; on either side of midline 

 there is a white-pruinose triangle, its base contiguous to the anterior 

 margin of mesonotum, its apex extending posteriorly to the prescutel- 

 lar region which is also white-pruinose ; a few long, narrow, yellow 

 scalelike hairs on dorsum, more numerous on anterior half and in 

 prescutellar region, never in packets ; short black hairs over entire 

 mesonotum. Humeral angles yellow, covered with white pruinosity. 

 Scutellum light yellow to white, with yellow scalelike hairs and with 

 long black hairs. Postnotum light yellow, velvety, with white prui- 

 nosity, devoid of hairs. Pleura tan, with white pruinosity. Stem of 

 halter brown, the knob tan. Wings, 1.9 mm. long and 0.94 mm. wide ; 

 relation of body length to wing, 1.3 : i ; Sc pilose along basal third to 

 sixth (3 hairs on dorsal surface) ; Ri completely pilose, with spines 

 as well as hairs along distal two-thirds; R2+3 pilose except for very 

 short basal section ; Cuv arcuate ; discal cell absent. 



Legs: Leg i, length, 2.2 mm.; coxa, trochanter, and femur light 

 brown; tibia light brown with the posterior edge darkened; tarsus 

 black. Leg 2, length, 1.9 mm.; coxa bluish black; trochanter, femur, 

 and tibia yellow ; basi tarsus yellow, the apical half appearing black 

 owing to large number of heavy black hairs ; tarsal segments 2-5 black. 

 Leg 3, length, 2.3 mm. ; coxa brown to bluish black ; trochanter yellow ; 

 femur yellow with apex black ; basal half of tibia yellow, the apical 

 half black ; basal two-thirds of basitarsus and basal half of second 

 segment yellow, the remainder of these segments, as well as all of 

 segments 3-5, black ; relation of basitarsus to second segment, 4.3 : i ; 

 calcipala well developed, reaching pedisulcus; pedisulcus very small, 

 on basal third of second segment. 



Abdomen : Tergite of segment i yellow, with both short black 

 hairs and short yellow hairs ; pleurites yellow, partially white-pruinose, 

 with long yellow hairs and with some short black ones. Segment 2 

 yellow, partially white-pruinose, with few short black hairs. Tergites 

 of segments 3 and 4 black ; those of segments 5 and 6 with anterior 

 half yellow and posterior half black ; pleura of segments 4-6 yellow 



