384 PROCEEDINGS OF THE NATIONAL MUSEUM vol. io9 



long as broad) and an antennal ratio of 1.07-1.12. A series of speci- 

 mens measured from Trinidad, B. W. I., have the palpal ratio 2.15 to 

 2.64 and the antennal ratio 1.28-1.34. Furthermore, specimens from 

 Jaque in Darien Province and Rio Santa Maria in Veraguas have an 

 even slenderer palpus (2.4-2.73) and shorter distal antennal seg- 

 ments (antennal ratio, 1.02-1.19). 



The extreme development and confluence of the pale areas of the 

 wing and the unicolorous grayish brown mesonotum with a pattern of 

 narrow dark brown lines will readily separate paucienjuscatus from the 

 related species, mojingaensis and azureus. 



50. Culicoides pifanoi Ortiz 



Figure 53 



Culicoides pifanoi Ortiz, 1951, Rev. Sanid. Asist. Soc, vol. 16, p. 588 (male, 

 female; San Felipe, Yaracuy, Venezuela; fig. wing, mesonotum, palpus, 

 antenna, spermathecae, male genitalia); 1954, Arch. Venezolana Patol. 

 Trop. Parasit. Med., vol. 2, p. 225 (female; fig. wing, palpus, spermathecae, 

 antenna). — Fox, 1955, Journ. Agr. Univ. Puerto Rico, vol. 39, p. 251 (syno- 

 nym, tricoloratus Wirth and Blanton). 



Culicoides tricoloratus Wirth and Blanton, 1953, Journ. Parasit., vol. 39, p. 233 

 (male, female; Panama, Florida; fig. wing, mesonotum, palpus, male geni- 

 talia) . 



Female: Length of wing 0.79 (0.73-0.89, n = 9) mm. 



Head. — Eyes narrowly separated, bare. Antenna with flagellar 

 segments in proportion of 14 : 10 : 1 1 : 13 : 12 : 12 : 13 : 13 : 14 : 16 : 16 : 16 :26, 

 antennal ratio 0.91 (0.84-0.97, n = 6); distal sensory tufts present 

 on segments iii, vii-x. Palpal segments in proportion of 7:16:16: 

 7:7, third segment moderately swollen, 1.8 (1.6-1.9, n = 8) times as 

 long as greatest breadth, with a large, shallow sensory pit. Mandible 

 with 14 (12-15, n = 6) teeth. 



Thorax. — Mesonotum dark brown with a pair of elongate, sub- 

 median, yellowish spots on disc and two sublateral pairs of irregularly 

 rounded, bluish pruinose light spots. Scutellum narrowly dark 

 brown in middle, sides paler. Postscutellum dark brown, pleuron 

 light brown, darker across middle transversely. Legs dark brown; 

 fore and mid femora with subapical (a faint trace of subapical pale ring 

 on hind femur of some specimens), all tibiae with subbasal and hind 

 tibia with apical, narrow pale rings; hind tibial comb with four (n = 9) 

 spines, the one nearest the spur longest. 



Wing. — Pattern as figured, pale spot over r-m crossvein extensive; 

 poststigmatic pale spot consisting of a single spot extending from 

 anterior wing margin around end and posterior side of second radial 

 cell and narrowly connected proximad to the pale spot over r-m cross- 

 vein; distal pale spot in cell R5 more or less quadrate in outline with 

 one side meeting wing margin and one corner nearly meeting the pale 



