324 Annals Entomological Society of America [Vol. VI, 



50. Agromyza plumiseta, new species. 



Female: Frons black, center stripe opaque, orbits, ocellar region, 

 and the well defined ocellar triangle glossy black; breadth of frons 

 one-third the head width, ocellar triangle reaching three-fourths of the 

 way to luniile, which is whitish pollinose ; orbital bristles four in number, 

 moderately strong; hairs on orbits numerous and irregularly arranged; 

 ■each orbit one-fourth the width of center stripe; the bristles situated 

 ■close to inner margin; antennas of moderate size, deep black; third joint 

 rounded in front, not as long as broad; second joint with distinct dorsal 

 bristle; arista brown, swollen at base, pubescence very distinct, longer 

 than basal diameter of arista, length of arista equal to from its base 

 to upper orbital bristle; face black, concave, mouth margin slightly 

 produced; cheek very short and low; marginal bristles rather weak, 

 vibrissa well differentiated; proboscis yellow at apex; palpi black, 

 slightly spatulate, and weakly bristled at tips; occiput not projecting. 

 Mesonotum blue-black; two pairs . of dorso-centrals present; setulas 

 numerous on disk, continued posteriorly beyond transverse line of 

 posterior dorso-centrals; pleuras black, shining, with a bluish sheen, 

 the sutiu-es, and below wing base brown; squamae yellowish white, 

 fringe concolorous; scutellum colored as disk of mesonotum, apical 

 pair of bristles very slightly smaller than basal pair. Abdomen black, 

 with a distinct, metallic blue sheen; basal segment brown; all segments 

 with very niimerous discal setulcE, those on apices of segments most 

 distinct; sixth segment very slightly elongated; base of ovipositor 

 not longer than preceding segment. Legs black, shining, strong; 

 posterior surface of mid tibia with the pair of bristles distinct. Wings 

 clear; veins brownish yellow; first costal division barely more than one- 

 third as long as second; inner cross vein at below end of first vein and 

 at middle of discal cell; outer cross vein at very slightly beyond wing 

 middle, and at more than its own length from inner; veins 2-3-4 grad- 

 ually divergent on their last sections; last section of fifth vein about 

 two-thirds as long as penultimate section. Halteres black. 



Length 2 mm. 



Type: Cat. No. 15586, U. S. N. M. 



Locality: Bayamon, Porto Rico, January, 1899, (A. Busck) 

 Along with the type there is a male from Fajardo, Porto Rico, 

 February, 1899 (A Busck), which belongs here. It differs 

 only in having the frons slightly less than one-third the head 

 width and though in poor condition is evidently, in other 

 respects, identical with the female. 



Food-plant unknown. 



