132 Annals Entomological Society of America [Vol. XII, 



Erax parvulus Bellardi. 



Total length 13 to 15 millimeters. Mystax and beard white, the 

 former with black bristles intermixed. Disc of scutellum and rear of 

 mesothorax white haired. Margin of scutellum with a few black bristles. 

 Wings hyaline. Femora, except at extreme apex, black, apexes of 

 femora, tibia and tarsi red. Male, first three abdominal segments 

 dorsally black, narrow posterior margins of two and three and all of 

 four, five, six and seven silvery. Hypopygium black. See Figure 55. 

 Female abdomen black, narrow sides and hind margin of each segment 

 gray pollinose, oviduct slightly longer than the last three abdominal 

 segments. 



Male and female from Guerrero, Mexico. 



Erax unicolor Bellardi. 



Total length 16 to 19 millimeters. Mystax pale yellow with a few 

 black bristles, beard pale yellow, palpi black haired, mesothorax with 

 black hairs and bristles, scutellum with white hairs and a few black 

 bristles on its margin, femora black to near the tips, apexes of femora 

 and tibiae and tarsi red. Abdominal segment one and base of two gray, 

 apex of two, and whole of segments three to seven, inclusive, silvery; 

 segments two, three, four and five with long white hair parted at the 

 middle and directed outward. Hypopygium black, emarginate at the 

 tip. See Figure GO. 



Female colored much as in the male, abdominal segments two to 

 seven each with a dark triangle dorsally, oviduct about as long as the 

 last three abdominal segments. 



-■b'- 



A male and female from Amatitlan, Guatemala, and five 

 males and females from Tehauntepec, Mexico, (Sumichrast). 



Erax latrunculus Williston. 



Total length 15 to 18 millimeters. Mystax white with a very few 

 black bristles, beard white, rear of the mesothorax and disc of the 

 scutellum with white hair, margin of the scutellum with several black 

 bristles, femora all black, tibice and tarsi red. . Male, abdominal seg- 

 ments one to five each with a black spot above, large on segments two, 

 three and four, small on five. Sides and hind margin of two to five 

 inclusive and all of six and seven silvery. In one specimen six is all 

 silvery, lacking the dorsal black spot. Hypopygium shining black, 

 mostly with pale hairs. See Figure 56. 



Female, abdominal segments one to seven inclusive each with a 

 black spot above, sides and hind margin of each segment densely 

 gray pollinose. Oviduct somewhat shorter than the last three abdominal 

 segments combined. 



Male and female from Arizona. This description is taken 

 from specimens from Cornell University. Professor Bradley 



