NO. I BLACK FLIES OF GUATEMALA — DALMAT IO7 



GIGANTODAX WRIGHTI Vargas, Martinez, and Diaz 



Simulium (Gigantodax) wrighti Vargas, MartInez, and Diaz, Rev. Inst. 

 Salubr. Enferm. Trop., vol. 5, No. i, pp. 37-41, figs. i-7, i944 (original de- 

 scription, photographs of c? and ? genitalia, posterior leg of $, and pupal 

 respiratory apparatus; comparison of c? genitalia with those of G. arau- 

 canium). 



Simulium (Gigantodax) vargasi DeLeon, Bol. Sanit. Guatemala, vol. 52, pp. 

 69-70, figs. 5-6, 1944 (pupal respiratory apparatus). 



Gigantodax wrighti Vargas, Martinez, and Diaz, Rev. Inst. Salubr. Enferm. 

 Trop., vol. 7, No. 3, p. 165, figs. 138 and 147, 1946 (larva). — D'Andretta 

 AND D'Andretta, Jr., Pap. Avulsos Dept. Zool., Sao Paulo, vol. 8, No. 2, 

 PP- 23-37, 32 figs., 1947 (redescription of ?, S, and pupa). 



Male (pi. 22, figs. 13-15). — 3.5 mm. long. 



Head : Holoptic. Eyes reddish brown above, black beneath. An- 

 tennae 710 ju, long, ii-segmented; scape, pedicel, and first flagellar 

 segment of same width, the remaining segments being somewhat nar- 

 rower but about equal in width to each other, segment 1 1 blunt ; seg- 

 ment 3<i4- 2, 3=4-1-5, 3>ii; scape and pedicel yellow, the flagellum 

 brown with yellow pruinosity and short yellow hairs. Palpi dark 

 brown. Clypeus dark brown, white-pruinose, and with yellow scale- 

 like hairs and some longer yellow hairs. 



Thorax: Mesonotum orange to brown, with white pruinosity in 

 the prescutellar region, covered with narrow, yellow, scalelike hairs, 

 the hairs in the prescutellar region and on most of periphery much 

 longer. Humeral angles brown, white-pruinose, with yellow hairs. 

 Scutellum rust brown, white-pruinose, with long yellow hairs. Post- 

 notum rust brown, with white pruinosity, devoid of hairs. Pleura 

 brown, with white pruinosity. Stem of halter light brown at base and 

 darker at apex ; the knob dark brown, flat. Wings, 3.8 mm. long and 

 1.7 mm. wide; relation of body length to wing, i : i.i ; Sc completely 

 pilose ; Ri completely pilose, the distal half also spiny ; hairs and 

 spines arranged in a single row ; R2+3 pilose along its distal five-sixths ; 

 Cu2 straight ; discal cell absent. 



Legs: Leg i, length, 3.2 mm. ; coxa brown ; trochanter brown, the 

 basal half somewhat lighter; femur brown with dark-brown apical 

 ring; basal and apical thirds of tibia dark brown, the median third 

 lighter ; outer edge of median third also dark ; tarsus brown. Leg 2, 

 length, 3.0 mm. ; coxa brown ; trochanter brown, its apical half some- 

 what lighter; femur, tibia, and tarsus as on leg i. Leg 3, length, 

 3.9 mm. ; coxa and trochanter brown ; femur as on leg 2 ; tibia brown 

 with basal and apical dark-brown rings ; tarsus brown ; basitarsus with 

 margins parallel to each other, its relation to second tarsal segment, 

 7.2 : I ; calcipala very well developed, almost covering entire second 

 segment ; pedisulcus absent. 



