82 



THE HOUSE FLY AND ITS ALLIES. 



cies, the M. vomitoria, is the Meat fly. Closely allied ai'e the 

 parasitic species of Tachiua, which live within the bodies of 

 caterpillars and other insects, and are among the most beueflcial 

 of insects, as they prey on thousands of injurious caterpillars. 



N^V/ 



Another fly of this Muscid group, the Idia 



Bigoti, according- to Coquerel and Mondiei-e, 



produces in the natives of Senegal, hard, red, 



fluctuating tumors, in ■which the larva resides. 



Many of the smaller Musclds mine leaves, 



ruuniug galleries witliin the leaf, or burrowing 



in seeds or under the bark of plants. We have 



often noticed blister-like swellings on the 



bark of the willow, which are occasioned by a 



cylindrical, short, fleshy larva (Fig. 88 a, much 



enlarged), about a line in length, which changes 



to a pupa within the old larval skin, assuming 



87. Larva of a the form here represented (Fig. 886), and about 



Sargus-like fly. the last of June changes to a small black fly 



(Fig. 88), which Baron Osten Sackeu refers doubtfully to the 



genus Louchsea. 



The Apple midge frequently docs great mischief to apples 

 after they are- gathered.' Mr. F. G. Sanborn states that nine- 

 tenths of the apple crop in Wreutham, Mass., were destroyed 

 by a fly supposed to be the Molobrus mali, or Apple midge, 



described by Dr. 

 Fitch. "The 

 eggs Avere sup- 

 posed to have 

 been laid in 

 fresh apples, in 

 the holes made 

 by the Coddling- 

 moth (Carpo- 

 c a p s a p o m o - 

 nclla), whence the larvas penetrated into all parts of the apple, 

 working small cylindrical burrows about one-sixteenth of an 

 inch in diameter." Mr. "W. C. Fish has also sent me, from 

 Sandwich, Mass., specimens of another kind of apple worm, 

 which he writes has been very common in Barnstable count}'. 

 " It attacks mostly the earlier varieties, seeming to have a par- 

 ticular fondness for the old fashioned Summer, or High-top 



W*illow mister flr. 



