ECONOMIC ZOOLOGY ENTOMOLOGY. 157 



and litter from the stable, the manure on the platform was sprinkled with 

 enough water to moisten it thoroughly without causing any leaching. The re- 

 sults obtained during August and September seemed to show that at least 98 

 per cent of the larvae breeding in this manure were destroyed by migrating 

 from the manure and dropping into the water below. Fly counts made before 

 and after the trap was installed indicated an average reduction of from 67 to 

 76 per cent. That the reduction of flies did not correspond to the percentage of 

 larvae destroyed is thought to have been due to the presence of several other 

 breeding places well within the range of flight. 



" Two difliculties were experienced in the practical working of the trap, viz, 

 the accumulation of a certain amount of straw and debris on the floor under the 

 platform and the breeding of mosquitoes in the water used to drown the fly 

 larvse. It was also found that low air temperatures hinder migration, and con- 

 sequently decrease the efficiency of the trap." 



Among the merits of the maggot trap mentioned are (1) the comparatively 

 small initial cost and absence of money outlay necessary for its maintenance ; 



(2) the very small amount of additional time or labor required in its operation; 



(3) the ease with which wagons or manure spreaders can be loaded from the 

 platform; and (4) its adaptability for use at stables where the daily produc- 

 tion of manure is large. The conditions which render the trap most effective 

 are the ones which tend to preserve the value of the manure. 



A list of nine references to the subject is included. 



Observations on blow flies; duration of the prepupal stage and color de- 

 termination, P. W. Whiting (Biol. Bui. Mar. Biol. Lah. Woods Hole, 26 (1914), 

 No. 3, pp. 184-194)- — ^The studies here reported upon relate to experiments 

 with the various si^ecies of blow flies common in New England, especial atten- 

 tion being given to the common green bottle fly (Lucilia sericata). 



The author finds that the length of the prepupal period of blow flies Is 

 determined by environmental rather than hereditary factors. In general, 

 dryness, cold, or agitation due to crowding tend to prevent pupation, while 

 change from dryness to dampness or the reverse induces it. "The prepupal 

 stage may be extended for a long period, four months in one experiment, in 

 warm temperature without injury to the development of adult flies, which 

 emerge from the pupae in normal condition. Lack of opportunity for the l«rvae 

 to bury themselves does not inhibit pupation. Exhaustion of the food supply 

 before the larvae have attained full size has a tendency to produce undersized 

 but normally formed flies. The causes producing misshapen and imperfectly 

 expanded flies are more obscure, but may be in part due to drying of the pupae. 

 Delayed pupation in Lucilia larvae is evidenced by a change from white to pink 

 in the fat bodies, but in two genera of larger flies, Cynomyia and Calliphora, 

 the white color is maintained although considerable shrinkage of the whole 

 body occurs. There is no evidence that overfeeding delays pupation, but much 

 evidence that larvae will pupate immediately despite the fact that they have had 

 abundant opportunity to overeat." 



A tachinid parasite with an intracuticular stage, W. R. Thompson (Compt. 

 Bend. Acad. Sci. [Paris], 160 {1915), No. 2, pp. 83-86, figs. 2).— This article 

 relates to an undetermined tachinid parasite, probably belonging to the 

 genus Epalpus, the first larval stage of which is parasitic on noctuid cater- 

 pillars taken by the author on witch-hazel {HamemaUs virginiana) brush at 

 Ithaca, N. Y. 



Sarcophagldae of New England: Males of the g'enera Ravinia and 

 Boettcheria, R. R. Parker {Proc. Boston Soc. Nat: Hist., 35 (1914), No. 1, pp. 

 77, pis, 8), — This first paper deals with seven species belonging to three genera, 



