THE ANTHOMYIA EGG-PARASITE. 287 



no eggs in them, but were full of these worms or larvse, each one of which took the 

 place of an egg which it had destroyed. Some of the egg-cases contained only two or 

 three larvae with more than twenty sound eggs. — [Prof. F. H. Snow, in Lawrence 

 (Kansas) Journal, November 1, 1876. 



I have just returned from quite an extensive trip to the Upper iCtinnesota. I send 

 by mail a few larvae and pupse, in two little paste-board boxes, of Anthomyia, I pre- 

 sume. I found them thick in a strip of rich, black soil, where the hatching was sud- 

 denly arrested by a heavy rain on the 20th ; and as the ground was low, the water 

 stood there for several hours. On digging, I found plenty of cases where the 'hoppers 

 had emerged from the shell (but not from the skin), and had stopped there, apparently, 

 without strength to go any farther ; but on digging them up and letting them stand 

 in the sun for a few minutes, they came out all right. The larvae that I send were 

 very thick in these nests, sometimes half a dozen in one nest, and had eaten many of 

 them out clean.— [Allen Whitman, Saint Paul, Minnesota, May 30, 1877. 



Large numbers of the flies and of the worms were reported in differ- 

 ent parts of Kansas last spring by oar special assistants, and we never 

 dug for five minutes among the locust eggs, anywhere in our travels 

 during the month of May, without finding this parasite in various stages 

 of development. Yet previous to 1876 no such enemy of these eggs 

 had ever been recorded. 



"This good little friend, which simultaneously prevailed over so large 

 an extent of country, is a small white maggot (Fig. 21, c) of the same 

 general form of the common meat maggots or ' gentles,^ but measuring, 

 when full grown and extended, not quite one-fourth of an inch in length. 

 The head, with some of the anterior joints of the body, tapers and is 

 retractile, and the jaws consist of two small hooks joined to a Y-shaped, 

 black, horny piece, which, as it is retracted or extended, plays beneath 

 the transpareut skin. The hiud or tail end is squarely docked off, and 

 contains two small yellowish -brown, eye-like spots, which are the prin- 

 cipal spiracles or breathing pores. 



" These small maggots are found in the locust-egg-i)ods, either singly 

 or in varying numbers, there sometimes being a dozen packed together 

 in the same pod. They exhaust the juices of the eggs, and leave noth. 

 ing but the dry and discolored shells ; and where they are not numer- 

 ous enough to destroy all the eggs in the pod, their work, in breaking open 

 a few, often causes all the others to rot.'^ 



When full grown, this maggot contracts into a stiff, cylindrical 

 puparium, rounded at both ends, and of various shades of brown in color 

 (Fig. 21, h). Within this hardened case the true pupa is formed, and 

 *' in the course of a week in warm weather, and longer as the weather 

 is colder, there issues a small, grayish, two-winged fly (Fig. 21, a), about 

 one-fourth of an inch long, the wings expanding about one-half of an 

 inch, and in general appearance resembling a diminutive house-fly, ex- 

 cept that the body is more slender and more tapering behind, and the 

 wings relatively more ample. More carefully examined, the body is 

 seen to be of an ash-gray color, tinged with rust-yellow, and beset with 

 stiff, bristle-like hairs, those on the thorax stoutest, and those on the 

 abdomen smaller but more uniformly distributed. The wings are faintly 



