122 The Rocky Mountain Locust. 



The probabilities are that, feeding normally on the roots 

 of various plants, it found locust eggs to its liking, and 

 multiplied rapidly as a result of the abundance of such 

 eggs. 



Anthomyia radicum (Linn.) var. calopteni. 

 Egg — Oval, smooth, white, 0.04 inch long. 



Larva— Skin unarmed, 0.24 inch long when extended, of the 

 normal form, the mandibular hooks black, quite conspicuous, and 

 diverging at base. Prothoracic spiracles elongate. Anal spiracles 

 minute, yellowish-brown, with the eight fleshy surrounding tuber- 

 cles, small. • 



Pupa — Pale-brown, rounded at each end, with the prothoracic 

 spiracles and lips anteriorly, and the anal spiracles and lower 

 tubercles posteriorly, showing as minute points. 



Imago — $. Average expanse, 0.48 inch. General color ash- 

 gray, with a ferruginous hue, especially above, and a more or less 

 intense metallic reflection. Face with white reflections below; eyes 

 smooth, brown, encircled by the ground color, and this behind and 

 on forehead, bordered by a brown line ; two similar lines at back 

 of head from upper corners of eyes, and approaching to neck ; 

 forehead dusky brown, becoming bright yellowish-red toward base 

 of antennas, and the brown forking at right angles around occiput. 

 Trophi and antennas black, the style simple and somewhat longer 

 than the whole antennas. Thorax with three dusky longitudinal 

 lines, obsolete behind ; legs black, with cinereous hue beneath ; 

 wings faintly smoky, with brown-black veins, the discal cross- 

 vein straight and transverse, the outer one bent and more oblique ; 

 balancers crumpled, yellowish. Abdomen with faint dusky medio- 

 dorsal spots, broad at base, tapering and obsolescing toward end 

 of each joint. 



In the 8, aside from the larger eyes, stronger bristles, and nar- 

 rower, less tapering abdomen, with its additional joint — all charac- 

 teristic of the sex — the face is whiter, and the medio-dorsal dark 

 mark of abdomen continues. 



Described from 25 specimens of both sexes, reared from locust 

 egg-feeding larvae. 



Specimens bred from cabbage and radish roots, and others in my 

 cabinet, taken from the burrows (made in Osage Orange, in Mis- 

 souri), of Crabro stirpicola, Pack., do not differ specifically. 



