no 



PRINCIPAL HOUSEHOLD INSECTS. 



species all over tlie United States aiid is mainly responsible for the 

 injury to canned fruits and pickles. 



All of the species of Drosophila are probably rapid breeders. Care- 

 ful descriptions of the early stages of B. ampelophila and I). amoena 

 are given by Professor Comstock in the Annual Report of the Depart- 

 ment of Agriculture for 18S1-82. The first-named species he calls the 

 vine-loving pomace fly, and he met with it frequently in the course of 

 an investigation of the apple maggot (Trypeta pomonella), the flies en- 

 tering apples which bad been injured by the Trypeta, completing the 

 work of disintegration and hastening decay. They are found com- 

 monly, according to Comstock, about the refuse of cider mills and fer- 

 menting vats of grape pomace. D. amoena he found to be associated 

 with the former species in apples previously damaged by the Trypeta, 

 but it was not so abundant as D. ampelophila. The larvae of both 



Fig. 51. — Drosophila ampeloj)hila : a, adult fly; b, antenna; c, base of tibia and first tarsal joint; d, 

 puparium, side view ; e, same, dorsal view ; /, larva ; g, anal segment of same — a, d, e, f, much enlarged ; 

 b, c, g, still more enlarged (original). 



species, and presumably other species of the genus as well, are fur- 

 nished with strong anal spiracles through which the larva? is able to 

 breathe by protuding simply the end of its body to the air. There are 

 also delicate tufts about the anal spiracles which may be branchial in 

 their character. 



Professor Forbes, in the Transactions of the Illinois State Horticul- 

 tural Society, 1884, mentions the damage done by I), ampelophila to the 

 grape crop at Moline, 111. He states that they attack most frequently 

 grapes which have been mutilated by birds or damaged by rot, but 

 once having commenced on a cluster are likely to pass from one berry 

 to another, the flies meantime constantly laying eggs. 



Dr. Lintner, in his first report as State entomologist of lew York, 

 mentions the habits of the European species, showing that D. cellaris 

 occurs in fermented liquids i:i cellars, such as wine, cider, vinegar, and 

 beer, and also in decayed potatoes. He also states that a species had 

 been sent to him as damaging flour paste. He had observed particu- 

 larly a species which occurred in ajar of mustard pickles. The larvae, 



