BITING MIDGES — WIRTH AND BLANTON 313 



proportion of 15:35:50:20:20, third segment moderately swollen, 1.91 

 times as long as greatest breadth, sensory pit deep, with broad open- 

 ing near apex of segment. Mandible with 14 (13-14, n=6) teeth. 



Thorax — ^Mesonotum dark brown with dense golden brown pollen, 

 anterolateral corners broadly blackish. Scutellum dark brown, 

 pleuron blackish. Legs yellowish, narrow knee spots black; femora 

 with broad blackish bands extending from near extreme bases to 

 two-thirds of distance to apices, fore tibia brownish except at extreme 

 base, mid and hind tibiae with fainter infuscation on distal halves, 

 narrow apex of hind tibia blackish; hind tibial comb with four spines, 

 the one nearest the spur longest. 



Wing — Pattern as figured, appearing dark with large, more or less 

 isolated, rounded yellow spots, pale spot straddling vein Mi separated 

 from pale spot at end of second radial cell by a narrow dark area, 

 distal pale spot in cell Mi not attaining wing margin. Macrotrichia 

 abundant, extending nearly to base of anal cell, costa extending to 

 0.60 of wing length. Halter pale yellowish. 



Abdomen — Blackish, cerci yellowish. Spermathecae two, pyri- 

 form, subequal, each measuring 0.072 by 0.052 mm. 



Male genitalia: Ninth sternum narrow, with broad, shallow, 

 caudomedian excavation; ninth tergum with short, bluntly pointed, 

 apicolateral processes, the caudal margin between them slightly 

 notched medially. Basistyle with ventral and dorsal roots each 

 long and slender, mesal surface without spinose setae. Aedeagus 

 with heavily sclerotized basal arms, a faintly sclerotized anterior 

 membrane forming a rounded basal arch, distal stem stout and 

 tapering slightly to a bluntly rounded apex. Parameres separate, 

 each with bent, knobbed base, nearly straight, slender stem and 

 slender, recurved, simple pointed apex. 



Distribution: Panama. 



Panama records: 

 CniRiQuf Province: Volcan (type locality). 



Discussion: The more typical, only moderately swollen, third 

 palpal segment will separate chrysonotus from the other three species 

 of this group with black knees, lutealaris Wirth and Blanton, nigri- 

 genus Wirth and Blanton and decor (Williston). In size, mesonotal 

 and leg color, and general appearance it is most clearly related to 

 lutealaris, but that species has more extensive pale wing markings, 

 with the distal pale spot in cell Mi extending to the wing margin and 

 the pale spot at the end of the second radial cell not separated from 

 the pale spot straddling vein Mi. 



