TWENTY-FIFTH ANNUAL MEETING. 115 



jars. The breeding-cage notes show that the egg state is about four days, the larvee 

 state about two weeks, and the pupal state one week. The adult flies lived in the 

 breeding jars from six days to two weeks after issuance from the puparias. Larvae 

 kept with ham and bacon did not take at all kindly to cheese, to which they were 

 removed, although the fly is undoubtedly identical with the cheese-skipper fly. 



The hams in the packing houses are smoked in a long shaft; adjoining the shaft 

 are large rooms, into which the smoked hams are removed, and there inclosed in the 

 cloth sacks. In these smoky rooms, and in the smoke-filled shaft itself, the adult 

 flies swarm and lay their eggs on the hams. The sacks are put on the egg-infested 

 hams, and the meat shipped. In the meanwhile the larvae hatch, and the consumer 

 removes the sack only to find a "skippery" ham. The problem is to prevent ovi- 

 position on the hams in the smoke shaft and in the bagging rooms. Measures rec- 

 ommended by Doctor Williston are now being tried, with what degree of success 

 cannot yet be told. 



The Feementing Fbuit Flies {Drosophila species). 



Among some grapes of a small black variety, received from Mr. G. C. Brackett, sec- 

 retary State Horticultural Society, several had broken skins, and the exposed juice 

 vias fermenting. In these fermenting grapes were to be found small dipterous larvas, 

 footless, and without other mouth parts than the hooks. They were about three- 

 sixteenths of an inch in length when full-grown. Some of the infested grapes were 

 isolated on October 1, and on the morning of the 4th the adult flies were obtained. 

 They proved to be Drosophila ampelophila Loew, called by Doctor Williston the fer- 

 menting fruit fly, by Lintner the pickled-fruit fly, and by Comstock the vine-loving 

 pomace fly. About 25 species of North American Drosophilas have been described, 

 mostly by the late Doctor Loew and Mr. Walker of the British museum. They are 

 all "fermenting" fruit flies, being attracted by any decomposing fruits. Doctor 

 Williston has seen them in clouds about heaps of cider refuse. Doctor Lintner notes 

 the occurrence of the species ampelophila in decaying peaches, and probably in 

 sweet jam and sour pickles. 



The flies are small, but brightly colored. The specimens bred from the Brackett 

 grapes, species ampelophila, have bright red eyes, generally pale yellow bodies, with 

 the last abdominal segment of the female and the last two of the male smoky black 

 above. The wings are clear, being entirely unspotted. The flies are about one- 

 tenth of an inch long. 



The flies lay their eggs on or in the fermenting fruit, and the larv« or maggots 

 hatch in three or four days. The larvae feed on the fermenting fruit about four days, 

 and then change to the pupal state, which lasts about four days longer. The adult 

 flies thus issue in about 12 days after the eggs are laid, and in their turn begin lay- 

 ing eggs in a couple of days after issuance. This fertility explains the large num- 

 bers of the flies. 



The fermenting fruit flies should not be mistaken for the true apple-worm flies 

 [Trypeta pomonella Walsh), the larvae of which attack sound fruit, causing it to de- 

 cay. The fermenting fruit flies attack only already unsound fruit. The adult fly of 

 the apple worm is white and black, and its wings are distinctly banded. The apple- 

 worm fly is also larger than the fermenting fruit fly, being about one-fourth of am 

 inch in length. 



Professor Comstock recommends inclosing the grape clusters in paper bags when 

 the fermenting fruit flies are found in vineyards, as in Mr. Brackett's case. "A few 

 pin holes should be made in the bottom of the bag, to allow the water to run out, 

 which otherwise, in case of a storm, would collect and either rot the grapes or burst 

 the bag." 



