BITING MIDGES — WIRTH AND BLANTON 295 



This group and the obsoletus group of the subgenus Culicoides 

 (Avaritia) reach their highest development in the Holarctic Region 

 with numerous North American and Eurasian species, particularly in 

 the far north. 



Panama Species: Two: elutus Macfie and luteovenus Root and 

 Hoffman. 



10. Culicoides elutus Macfie 



Figure 13 



Culicoides elutus Macfie, 1948, Ann. Trop. Med. Parasit., vol. 42, p. 75 (female; 



El Carrizal, Chiapas, Mexico; fig. wing). — Wirth and Blanton, 1956, Proc. 



Ent. Soc. Washington, vol. 58, p. 212 (male, female: Panama; fig. wing, 



palpus, spermatheca, male genitalia). 

 Culicoides cockerelli tristriatulus Vargas (misident., not Hoffman), 1945, Rev. 



Inst. Salub. Enf. Trop., vol. 6, pp. 45, 48 (Camotldn, Oaxaca, Mexico; fig. 



male genitalia). 



Female: Length of wing 1.14 (1.02-1.25, n = 14) mm. 



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

 proportion of 20:15:17:1717:17:17:17:20:21:23:24:35, antenna! ratio 

 0.93 (0.91-0.96, n=2); distal sensory tufts present on segments 

 III, xi-xv. Palpal segments in proportion of 10:26:30:12:12; third 

 segment strongly swollen, 2.5 (2.1-2.7, n = 10) times as long as greatest 

 breadth, abruptly narrowed beyond the large sensory pit. Mandible 

 with 16 (14-17, n = 14) teeth. 



Thorax. — Mesonotum and sciitellum uniformly dark pruinose 

 brown. Legs dark brown, small knee spots on all legs and narrow 

 bands on base and apex of hind tibia yellowish; hind tibial comb 

 with six spines, the second from the spur the longest. 



Wing. — Pattern as figured, roughly in form of three dark zig-zag 

 bands, each more or less broken into separate dark spots centering 

 on the veins, distal pale spot in cell R5 occupying entire apex of cell 

 to wing margin, distal pale spots in cells Mi and M2 broadly meeting 

 wing margin. Macrotrichia abundant, extending nearly to base of 

 wing and abundant in anal cell; costa extending 0.65 way from basal 

 arculus to wing tip. Halter yellowish white. 



Abdomen. — Blackish. Spermathecae two, subequal, suboval, each 

 measuring 0.083 by 0.053 mm. 



Male genitalia: Ninth sternum with deep caudomedian ex- 

 cavation; ninth tergum rounded caudally with moderately developed 

 apicolateral processes and a well-developed, hyaline, uncleft, caudo- 

 median lobe. Basistyle with dense, dark, spinose setae on mesal 

 face, dorsal and ventral roots well developed; dististyle with expanded 

 tip. Aedeagus massive, distal portion stout with a short, more 

 slender, caudomedian lobe. Parameres separate, slender, each with 



