BITING MIDGES — WIRTH AND BLANTON 323 



poststigmatic pale spot in cell R5 not double, but transverse; distal 

 pale spot in cell R5 round, not meeting anterior wing margin, with a 

 linear distal pale appendage extending from posterior side of spot 

 nearly to wing tip in apex of cell R5; distal pale spot in cell Mj broadly 

 meeting wing margin; pale spot present straddling middle of cell M2; 

 no pale marks on vein Mj or at apices of medial branches; pale spot 

 at apex of cell M2 broadly meeting wing margin; pale spot in cell M4 

 extending in full breadth from wing margin to vein M^+i, without 

 pale border on veins M3+4 or Cui in base of cell M4, two pale spots in 

 distal portion and one pale spot near base of anal cell, cell M2 with 

 pale spot present in front of mediocubital fork, none present behind 

 medial fork. Macro trichia numerous and long over entire wing; 

 costa extending to 0.58 of distance to wing tip. Halter dull yellowish. 



Abdomen. — Brownish black. Spermathecae two, subequal, pyri- 

 form, collapsed in type specimen and not measurable, with the bases 

 of the ducts sclerotized a short distance. 



Male genitalia: Ninth sternum with broad, shallow, caudo- 

 median excavation; ninth tergum long and slightly tapering with 

 long pointed apicolateral processes, the caudal margin not notched. 

 Basistyle with ventral root long and pointed, dorsal root slender; 

 dististyle slender with bent, pointed tip. Aedeagus with moderately 

 broad, pointed, basal arch, the basal arms well sclerotized and curved; 

 distal portion with nearly parallel sides and bluntly rounded, moder- 

 ately stout tip. Parameres each with large basal knob; stem sinuate, 

 basal portion distinctly swollen, tapered distad to bent, pointed tip 

 bearing a few minute hairs. 



Distribution: Panama. 



Specimens examined: Holotype female (USNM 63160) and allo- 

 type male, Almirante, Bocas del Toro Province, Panama, December 

 1952, F. S. Blanton, light trap. Paratypes: 2 males, 1 female, same 

 data except dates October to December 1952, and Apr. 27, 1953. 



Discussion: The wing markings, antennal sensoria, and structure 

 of the male genitalia ally commatis with pampoikilus Macfie, but 

 pampoikilus is larger (wing 1.25 mm. long), with distal antennal 

 segments longer (antennal ratio, 1.39), the main body of the distal 

 pale spot in cell R5 not round, veins M34.4 and Cui pale margined in 

 base of cell M4 and a pale spot present behind the medial fork. The 

 male genitalia of pampoikilus differ mainly in the greater development 

 of the apicolateral processes with a deep notch between their bases on 

 the caudal margin of the ninth tergum. 



