464 PROCEEDINGS OF THE NATIONAL MUSEUM vol. io9 



Discussion: The remarkable extension of the costa to nearly 

 eight-tenths of the wing length and the presence of only one radial 

 cell which tapers evenly from the linear base to the apex, the absence 

 of macrotrichia, and the larger size will readily separate uniradialis 

 from the closely related pachymerus Lutz and caprilesi Fox. 



The arubae group 



This group consists of moderately large, stout species with meso- 

 notal pattern of punctiform dots and black and white speckled wings; 

 costa short, to 0.52 of wing length; a pair of distinct frontal tubercles 

 present between antennal bases; antenna with short segments (anten- 

 nal ratio, 0.87), distal sensory tufts present on segments iii to x; 

 tibial comb with seven spines, two spermathecae ; male genitalia with 

 ventral root of basistyle long and slender; paramere with basal knob 

 du-ected sharply laterad, stem short and stout, the apex simple; 

 aedeagus short and stout with reflexed basal arms, low basal arch 

 and stout, truncated tip. 



This group contains only one species, arubae Fox and Hoffman. 

 It occurs in Panama. 



85. Culicoides arubae Fox and Hoffman 



Figure 88 



Culicoides arubae Fox and Hoflfman, 1944, Puerto Rico Journ. Pub. Health Trop- 

 Med., vol. 20, p. 109 (male, female; Aruba, D. W. I.; fig. wing).— Barbosa, 

 1947, Anais Soc. Biol. Pernambuco, vol. 7, p. 11 (Canal Zone, Venezuela; 

 fig. palpus, male genitalia) .—Ortiz and Mirsa, 1952, Rev. Sanid. Asist. Soc, 

 vol. 17, p. 269 (male, female; Venezuela; fig. palpus, spermathecae, male 

 genitalia) . 

 Female: Length of wing 1.17 (1.11-1.23, n=3) mm. 

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

 segments in proportion of 22:13:13:13:13:12:12:11:15:15:16:17:32, 

 antennal ratio 0.87; distal sensory tufts present on segments iii to x. 

 Palpal segments in proportion of 15:30:48:11:11, third segment 

 swollen, 2.3 (2.1-2.7, n=3) times as long as broad, with a very broad, 

 shallow sensory pit. Mandible with 15 (14-16, n=5) teeth. 



Thorax.— Mesonotum. very broad and convex; densely pale grayish 

 pruinose; narrow median and two broader sublateral vittae indis- 

 tinctly yellowish brown fumose; mesonotum with numerous puncti- 

 form brown dots at the seta bases. Scutellum narrowly dark brown 

 in middle, yellowish white pollinose on sides; postscutellum grayish 

 pollinose with two lateroposterior blackish spots; pleuron brownish 

 black. Legs dark brown and distinctly annulated; narrow knee 

 joints pale, knees with narrow blackish rings and then narrow pale 

 rings on each side on femora and tibiae, femora narrowly pale at 



