no 



PRINCIPAL HOUSEHOLD INSECTS. 



species all over the United States and is iiiaiuly 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. ampelopliila and D. amoena 

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

 ment of Agriculture for 1881-82. The first-named species he calls the 

 vine-loving i)omace 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 had 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 x^omace. D. amoena he found to be associated 

 with the former species in apples previously damaged by the Tr^qjeta, 

 but it was not so abundant as B. ampelopliila. The larvae of both 



Fig. 51. — Drosophila ampelo2}hila : o, adult fly; 6, 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 ; 

 6, 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 larvae 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>. ampelopMla 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 i^ew York, 

 mentions the habits of the European species, showing that i). cellar is 

 occurs in fermented liquids in 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, 



