28 COSTA RICAN DIPTERA 



^ APHIOCHAETA Brues 



Table of Species 



1. Frons glossy black '. . 2 



Frons brown or yellowish, or if black then with distinct poUinosity, 



never glossy - • 4 



2. Hind femora with the basal third yellow, the remainder black; costal 



fringe about the length of the diameter of costal vein 



femoralis Enderlein 



Hind femora entirely brown or black; costal fringe at least twice as long 



as diameter of costal vein 3 



3. Base of wing clear yellow; costal fringe very close, the bristles about 



5. times as long as diameter of costal vein; hind tibial setulae dis- 

 tinctly less than equal to diameter of tibia. . .littoralis new species 

 Wing not yellow at base; costal fringe not very close, the bristles equal 

 in length to about two times the diameter of the costal vein; hind 

 tibial setulae at middle about equal to the tibial diameter 



polita Enderltin 



4. Frons deep black with grayish pollinosity on surface; black species; 



halteres yellow; costa slightly short of wing middle 



pruinosa new species 



Frons at most brown-black, sometimes shining; yellow or brown species ; 



halteres black or yellow ; costa generally to wing middle or beyond. 5 



5. Halteres black or brown, never yellow 6 



Halteres yellow 10 



6. Costal fringe short and close, 12 bristles occurring from above end of 



first vein to anterior fork of third; fork of third vein acute 



sylvicola new species 

 Costal fringe long and much more widely separated 7 



7. Costa reaching to distinctly beyond middle of wing 8 



Costa reaching to wing middle or short of it 9 



8. Hind tibial setulae very indistinct and weak; first costal division not 



longer than second ; flavopleura new species 



9. Mesopleura with short bristles latimanus new species 



Mesopleura bare alajuelensis new species 



10. Robust species; halteres with knob lemon yellow; costal fringe short 



and close, 12 bristles from end of vein 1 to anterior branch of fork 

 of 3; fork very small; cf hypopygium with 4-5 strong bristles on 



either side ventrally seticauda new species 



Comparatively slender species; halteres reddish yellow 11 



11. Costal fringe short and close, the length of the bristles being about 



twice the diameter of the costal vein or less 12 



Costal fringe much longer than above 13 



12. Costa very weak haired (fig. 4); veins very weak on disk of wing; legs 



with soft hairs, no distinct setulae on hind tibia 



pilosa new species 



