552 EXPERIMENT STATION RECORD. 



A synopsis of the genera of Agromyzidae, with descriptions of new genera 

 and species, J. R. Malloch {Proc. U. 8. Nat. Mus., 46 {1914), pp. 127-154, 

 pis. 3). — A synopsis of a dipterous family of considerable economic importance. 



An account of the bionomics and the structure of dipterous larvae occur- 

 ring in human foods with particular reference to those which have been 

 recorded as accidental parasites of man. — I, The cheese skipper (Piophila 

 casei), D. C. Mote (Ohio Nat., 14 {1914), No. 7, pp. 309-316, figs. 16).— "The 

 cheese skipper because of its ravages on cheeses and smolied meats and its 

 possible relation to myiasis is of considerable economic importance. The fly 

 deposits its eggs upon bacon, cheeses, smoked ham, slightly putrid beefsteak. 

 Duration of egg stage, 23 to 54 hours. Larvae feed upon bacon, cheese, ham. 

 beef, oleomargarine. This insect gets its common name from the peculiar 

 leaping or skipping habit of the larva. Duration of larval instar, 14 days. 

 Pupation occurs in drier places than those in which the larvae feed. Duration 

 of pupal stage, 12 days. The flies in an experiment seemed to prefer beefsteak 

 with a slightly putrid odor in preference to ham, bacon, or cheese for egg deposi- 

 tion. The adult flies lived longer, and the larvae fed and matured more readily, 

 on the beefsteak than on the other substances." 



Biological notes concerning Drosophila ampelophila, F. E. Ltjtz {Jour. 

 N. Y. Ent. Soc, 22 {1914), No. 2, pp. 134-138) .—Da.t-A are presented on the 

 development of the different stages of the pomace fly. based on observations 

 of some 400 individuals. 



The biology of Ceratophyllus fasciatus, the common rat flea of Great 

 Britain, C. Strickland {Ann. Rpt. Local Govt. Bd. [Gt. Brit.], 42 {1912-13), 

 8up. Rpt. Med. Off., pp. 401-412; Jour. Hyg. [Camhridge], 14 {1914), No. 2, 

 pp. 129-142). — The results of life history studies of this flea have been sum- 

 marized as follows: 



" The duration of the various stages is very variable, even under the same 

 conditions. Temperature and humidity are the two conditions which have most 

 influence. ... On an average, the egg hatches out in 5 to 14 days, an increase 

 of humidity having a retarding, and a moderately high temperature a slight 

 accelerating effect. The larva is soon killed by a high temperature (70° F.) 

 combined with a low degree of humidity (40 per cent). However, under these 

 conditions, the larvse will live longer if rubbish is present, for they are then 

 able to bury themselves in it and thus obtain a certain amount of moisture. 

 The pupal stage is much prolonged by cold, but this is partly due to the 

 nonemergence of the imago, even when it is fully formed. The imago, at least 

 when unfed, dies off much more rapidly in summer than in winter. Eggs 

 are laid by the imago even at comparatively low temperatures (50°). 



" The larvae and imagines like to bury themselves in rubbish, and under 

 these circumstances their duration of life is much prolonged, even when other 

 external conditions are somewhat severe. When copulating, the imago fre- 

 quently lives at least two months, but it will not copulate unless it is fed on 

 rat's blood. It feeds readily on man and many other animals, but will not 

 copulate after feeding on these facultative hosts, even though at least one of 

 them — man — seems to be more attractive to it than its normal host, the rat. 

 Oviposition invariably takes place within 24 hours of copulation, even when the 

 insect has only been fed once after being starved for a period of many weeks. 

 The rat's blood, therefore, probably contains some substance that possesses 

 a stimulating effect on the flea's sexual organs. When starved, the imago 

 will live for a very long time — at least 17 months — but only in the presence 

 of rubbish in which it can bury itself. In the absence of rubbish the flea will 

 only live for about a month, even under the most favorable conditions of tem- 

 perature and humidity. 



