l86 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I25 



No. 3, pp. 236-237, figs. 4 and 11, 1942 (c? and $). — Vargas, ibid., vol. 4, 

 No. 4, p. 368, figs. 30-32, 1943 (pupa). 

 Simtiliwn (Dyarella) mexicanum Bellardi, Vargas, Martinez, and Diaz, Rev. 

 Inst. Salubr. Enferm. Trop., vol. 7, No. 3, p. 179, fig. 139, 1946 (larva). 



Male (pi. 24, figs. 58-60). — 3.5 mm. long. 



Head : Holoptic. Eyes very dark reddish brown, shiny, with row 

 of hairs between them. Antenna 570 jx long, ii-segmented, slightly 

 tapering; segment 3 two-thirds length of segments i and 2 together; 

 remainder of segments subequal ; dark brown. Palpi dark brown. 

 Clypeus brown with white pruinosity. 



Thorax : Mesonotum velvety black, evenly covered with gray 

 pruinosity, with 3 longitudinal lines of base color showing, one down 

 midline and one on either side of this central one ; numerous long, 

 narrow, yellow, scalelike hairs on all parts of mesonotum, these 

 grouped in packets on anterior half, but single on posterior half ; short 

 black hairs over entire mesonotum, longer in prescutellar region. 

 Humeral angles white-pruinose. Pleura evenly white-pruinose. Scu- 

 tellum light brown, with tufts of long black hairs on its sides. Post- 

 notum velvety brown, with white pruinosity, but without hairs of 

 any kind. Stem of halter brown, the knob bright yellow, cuplike, 

 large. Wings, 3.5 mm, long and 1.5 mm. wide; relation of length of 

 body to wing, 1:1; Sc pilose along its basal sixth ; Ri with spines 

 along its distal half, these intermixed with very few hairs ; R2+3 pilose 

 except for very small basal region ; Cu2 arcuate ; discal cell absent. 



Legs : Leg i, length, 4.2 mm. ; coxa, trochanter, and femur yellow ; 

 tibia brown, very wide; tarsus black. Leg 2, length, 3.1 mm.; coxa 

 and trochanter brown ; femur dark brown, with small light-brown 

 area on apex ; tibia dark brown to black, very hairy ; basal two-thirds 

 of basitarsus and basal fourth of second segment light brown, the re- 

 mainder of these segments, as well as all of segments 3-5, black. 

 Leg 3, length, 4.2 mm. ; coxa dark brown ; trochanter light brown ; 

 femur and tibia reddish brown, with very small light-brown area at 

 base, very hairy ; basitarsus with basal third light brown, the re- 

 mainder black, greatly expanded on distal half ; segments 2-5 black ; 

 relation of basitarsus to second tarsal segment, 6:1; calcipala well 

 developed, short, broad, straight, not reaching pedisulcus ; pedisulcus 

 on basal fourth, very small, hardly visible. 



Abdomen : Tergite and pleurites of segment i light brown, with 

 long black hairs that reach the fourth segment. Segment 2 black, its 

 anterior half white-pruinose. All other segments black, covered with 

 short brown hairs ; pleurites of segments 3-5 white-pruinose, with 

 short, yellow, scalelike hairs. Sternites dark brown with short black 

 hairs. 



