SOME INSECTS AFFECTING CHEESE, HAMS, FRUIT, ETC. 109 



[N'ovember the southern outer wall was speckled with them. He suc- 

 ceeded iu ridding the establishment b}' trapping them day after day 

 with a piece of cheese. The cheese proved to be extremely attractive, 

 and he destroyed them by hand two or three times a day until he had 

 practically exterminated them. Shortly after the introduction of the 

 Pasteur sj'Stem of silkworm moth inspection for pebrine in France, 

 according to Maurice Girard, great damage was done by this Dermcstid, 

 which attacked first the bodies of the moths as they were attached to 

 their egg receptacles. They laid their eggs in the moths, and tlieir larvcie 

 first ate the bodies and afterwards tlie silkworm eggs themselves, thus 

 occasioning in 1871 at Pont Gisquet a loss of one-third of the egg crop. 

 The remedial measures adopted were to screen the windows with a very 

 fine wire gauze to prevent the entrance of beetles and afterwards to 

 submit the rooms to fumigation with bisulphide of carbon or corrosive 

 sublimate. 



An interestiug case of damage to bacon was mentioned by Dr. Lint- 

 ner in the Cultivator and Country Gentleman for June 26, 1884. An 

 individual in Walkersville, Md., had found bacon hung up in ixai)er 

 meat sacks the 1st of March affected with beetles, and larv;e later in 

 the season, presumably in June. The beetles must have oviposited in 

 the bacon before sacking, or there must have been cracks in the paper 

 bags through which the young larv^v entered. The date of the bag- 

 ging renders the former hypothesis improbable. The instance seemed 

 to show the necessity for very careful and early bagging. The slightest 

 crack or slit in the paper would be large enough to allow the entrance 

 of the newly hatched larva, since the beetles will lay their eggs near 

 such a crack or slit. Dr. Lintner further advised a thorough white- 

 washing of the apartment in which the sacks were hung, which in this 

 case was a garret. 



THE FRUIT FLIES OR VINEGAR FLIES. 

 (Drosojihila spp.) 



There are in Xorth America about thirty species of light-brown flies 

 belonging to the genus Drosophila, of which perhaps the majority 

 breed in the juices of decaying and fermenting fruit. Their larvip are 

 vsmall, white, slender maggots, and are freiiuently found in canned fruits 

 and pickles whicli have been imperfectly sealed, occurring mostly near 

 the top of the jars, but living without inconvenience in the briny or 

 vinegary liquid and transforming within brown puparia around the 

 edges of the jar. The commonest species seem to be D. amjulophila 

 Loew and J), amania Loew. 



The majority of the species are strictly Xorth American, and this 

 includes the two specially mentioned in the paragraph above, although 

 D. (impdophUa has also b(^en found in Cuba. Several species, however, 

 are common to Europe and the Tniteil States, for exami)le, /). funcbris, 

 D. graminum, and D. transversa. D. ampelophila seems the commonest 



