SCENOPINIDAE OF THE WORLD 289 



Key to the Species of Prepseudatrichia 



1. Females 2 



Males, halter knob black-brown, thorax black, striated, legs straw j-ellow 



darkening to orange-brown posteriorly P. mateui, new species 



2. Thorax black, striated 3 



Thorax black with green and purple metallic glints, halter knob red-brown, 



velvety, legs straw yellow with tarsi red-brown . . P. violacea, new species 



3. Halter knob mahogany-brown, legs reddish, antennae orange, cell Cu ending 



abruptly P. stenogaster S^guy 



Halter knob red-brown to black, shining, legs straw yellow darkening to 

 orange-brown posteriorly, cell Cu long ending in a point 



P. mateui, new species 



193. Prepseudatrichia mateui, new species 



Figure 187 



Male. — Head black, longer than high; eyes red-brown above, 

 black-brown below, close but not meeting on the midline; frons very 

 narrow, slightly swollen above the antennae, a median groove above; 

 ocellar tubercle prominent; ocelli clear; a white patch above the 

 antennal bases; oral opening large; mouthparts cream, well developed, 

 with long hairs on flabellum; palpi long and slender. Antenna black- 

 brown; first segment short; second longer than first; third granular, 

 truncated not twice as long as wide; see figure for details. 



Thorax black, striated; dorsoventrally compressed, particularly in 

 prescutal area; a pollinose patch above the humeral callus; humeral 

 callus red-brown, narrow; pleural areas black-brown, shallow, the 

 front and middle legs more widely separated than normal. Wings 

 hyaline, veins brown, similar to Scenopinus; halter stem brown to 

 black-brown, knob red-brown to black, shining. Front leg straw 

 yellow with brownish yellow tarsus darkening distally; middle leg 

 with coxa and femur straw yellow tibia and tarsus brownish yellow 

 darkening distally; hind leg with all segments orange-brown, first 

 tarsal segment yellowish, rest red-brown. 



Abdomen second segment red-brown to black, segments three and 

 four with white posterior bands extending to lateral margins. Ninth 

 segment red-brown to black, hairy. Both external and internal struc- 

 tures separate this species from all others; see figure for details. 



Female. — Head black, rugose, longer than high; eyes yellow-brown; 

 with prominent postocular ridge, subshining; frons broad, rugose, with 

 a bulge above the antennae, a white patch above the antennal base, 

 wider than the ocellar triangle which is not prominent; ocelli brown, 

 mouthparts as in the male. Antennae black-brown, third segment 

 pear-shaped, darker at tip; see figure for details. 



Thorax as in male; legs as in male but darker. 



