136 MISC. PUBLICATION 63 1, U. S. DEPT. OF AGRICULTURE 



bends rather feebly upward, meeting the costa before the wing apex. Length, 

 about 8 mm. Larvae: It is difficult to distinguish the larvae from that of M. 

 assimilis, the only known characters for their separation being the structure of 

 the buccopharyngeal armature (fig. 79.) The newly hatched larva measures 

 about 1.5 mm. ; the mature third-stage larva, about 12-18 mm. in length by 

 5-6 mm. in width. The mature larva is creamy to grayish white ; its skin is 

 rather tough, but not so tough as in most carnivorous larvae ; the mouth hooks are 

 stouter than those of M. assimilis. 



Geographical Distribution. — Nearctic Region: Alaska, Nova Scotia, New 

 Brunswick. Quebec, Ontario, Alberta, British Columbia, Maine, New Hampshire, 

 Vermont, Massachusetts, Rhode Island, Connecticut, New York, New Jersey, 



Figure 79. — Anterior segments of larva of Muscina, side view: A, M. assimilis 

 first stage ; B, M. stabulans, same ; V, M. assimilis, second stage ; D, M. stabulans, 

 same; E. M. assimilis, third stage; F, M. stabulans, same. (After Seguy (134, 

 p. US), and Keilin (66).) 



Pennsylvania, Maryland, District of Columbia, Virginia, North Carolina, Georgia, 

 Ohio, Michigan, Indiana, Illinois, Minnesota, Wisconsin, Iowa, Missouri, North 

 Dakota, South Dakota, Kansas, Arkansas, Texas, Montana, Idaho, Colorado, 

 Utah, New Mexico, Washington, Oregon, California. Neotropical Region : Mexico, 





