310 PROCEEDINGS OF THE NATIONAL MUSEUM vol. io9 



individuals of nigrigenus, and in the leg markings, with broad 

 pale bands on each side of the knees. According to Williston's 

 original description, decor also differs in having the abdominal terga 

 blackish with pale segmental bands of integuroental coloring. 



Two Panama species, chrysonotus Wirth and Blanton and lutealaru 

 Wirth and Blanton, also have all the knees black, but these species 

 are larger and have darker, less hairy wings and the femora blackish 

 at the bases. 



18. Culicoides lutealaris Wirth and Blanton 



Figure 21 



Culicoides lutealaris Wirth and Blanton, 1956, Proc. Ent. Soc. Washington, vol. 

 58, p. 225 (male, female; Panama; fig. wing, palpus, spermathecae, male 

 genitalia). 



Female: Length of wing 1.56 (1.49-1.62, n=7) mm. 



Head. — Eyes contiguous, bare. Antenna with flagellar segments 

 in proportion of 20 : 1 8 : 18 : 1 8 : 18 : 18 : 18 : 1 9 : 38 : 38 : 38 : 42 : 60, antennal 

 ratio 1.3; distal sensory tufts present on segments iii-xv. Palpal 

 segments in proportion of 10:30:55:16:14, third segment greatly 

 swollen, 1.9 (1.7-2.1, n = 7) times as long as greatest breadth, with 

 an extremely large sensory cavity opening through a large pore. 

 Mandible with 14 teeth. 



Thorax. — Mesonotum dark brown, with dense, rather dark, yellow- 

 ish gray pollen; area around humeral pits and narrow lateral lines 

 blackish. Scutellum pollinose dark brown; pleuron brown, paler 

 above. Legs yellowish, knee spots black; femora with broad blackish 

 bands extending from near extreme bases two-thirds of distance to 

 apices, fore tibia brownish except at extreme base, mid and hind tibiae 

 with fainter infuscation on distal halves, narrow apex of hind tibia 

 blackish; hind tibial comb with four spines, the one nearest the spur 

 longest. 



Wing. — Pattern as figured, distal pale spot in cell Mi broadly 

 meeting wing margin. Macrotrichia abundant, extending nearly to 

 base of anal cell; costa extending to 0.58 (0.57-0.62, n=7) of distance 

 to wing tip. Halter yellowish. 



Abdomen. — Dark brown, terga with indistinct sublateral blackish 

 areas; distal apical integumental bands and faint pollen on entire 

 dorsum whitish, cerci yellowish. Spermathecae two, pyriform, sub- 

 equal, each measuring 0.060 by 0.048 mm. 



Male genitalia: Ninth sternum narrow, with a broad, shallow, 

 caudomedian excavation; ninth tergum with long, pointed, apicolat- 

 eral processes, the caudal margin between them, distinctly notched 

 medially. Basistyle with ventral and dorsal roots long and slender; 

 mesal margin without spinose setae. Aedeagus with heavily sclero- 



