386 PROCEEDINGS OF THE NATIONAL MUSEUM vol. io9 



Male genitalia: Ninth sternum with very shallow caudomedian 

 excavation; ninth tergum short and tapering with small apicolateral 

 processes. Basistyle with ventral root foot-shaped, the posterior heel 

 small, the toe slender, dorsal root slender; dististyle slender and curved 

 with slightly expanded apex. Aedeagus with basal arch extending to 

 about three-fourths of total length, narrow at the mesal apex, the 

 stout basal arms nearly straight; distal stem slender and flanked by a 

 subapical pair of sclerotized points. Parameres each with large basal 

 knob, stem slender at base, abruptly bent at about midlength of stem, 

 tliLs portion slightly swollen, the distal portion of stem tapering gradu- 

 ally, without ventral lobe, abruptly bent and tapered to fine apical 

 point, with a subapical fringe of well-developed barbs. 



Distribution: Venezuela; Florida; Honduras (Lancetilla) ; Nica- 

 ragua (Villa Somoza); Panama; Trinidad. 



Panama records: 



BocAS DEL ToRO PROVINCE: Almirante. 



Canal Zone: Barro Colorado Island, Fort Davis, Fort Sherman, Gamboa, Mad- 

 den Dam, Mojinga Swamp. 



Col6n Province: Pina. 



Dari^n Province: El Real, Garachin^, Punta Patino. 



Panama Province: Arraijdn, Cerro Campana, Pacora (type locality of tricolora- 

 tus). 



Discussion. — Among those species with dark second radial cell and 

 prominent mesonotal pattern and large distal pale spot in cell R5 

 broadly meeting wing margin, this species is readily identified by the 

 extensive pale margins to veins Mi and M2 which are connected to the 

 pale spots in cell Mi and in apex of cell R5, with the distal spot in cell 

 Ml much smaller than its distance from the wing margin. In some 

 specimens the bluish pruinosity of the lateral pale areas of the mesono- 

 tum is not evident and in some there is an indication of a subapical 

 pale band on the hind femur. 



51. Culicoides dicrourus Wirth and Blanton 



Figure 54 



Culicoides dicrourus Wirth and Blanton, 1955, Bull. Brooklyn Ent. Soc, vol. 50, 

 p. 123 (male, female; Panama; fig. wing, palpus, spermathecae, male geni- 

 talia). 



Female: Length of wing 1.14 (1.02-1.25, n= 10) mm. 



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

 segments in proportion of 19:16:16:16:17:17:17:17:23:25:27:27:41, 

 antennal ratio 1.04 (0.98-1.07, n = 4); distal sensory tufts present on 

 segments iii, vi-x. Palpal segments in proportion of 10:22:28:10:10, 

 third segment swollen, 2.1 (1.9-2.3, n = 8) times as long as greatest 



