ECONOMIC ZOOLOGY ENTOMOLOGY. 359 



"The presence of the incubating uterus, enveloped with tracheae, indicates 

 that the egg is held within the fly until the maggot is well formed. ... As 

 far as Cuterebra is concerned, we can feel quite confident that its host relation 

 is maintained through stealth, and that, barring accidents, the fly never comes 

 in contact with the host. The eggs are probably deposited in the burrows or 

 runways of the rabbits, rats, and other small mammals which it parasitizes." 



Notes on the habits of Dermatobia follow. 



Commensalism in Desmometopa, F. Knab (Proc. Ent. Soc. Wasli,., 17 (1915), 

 No. S, pp. 111-121). — Attention is called to the fact that agromyzids of the 

 genus Desmometopa feed on the juices of insects freshly ijilled by other 

 rapacious arthropods with which they are associated. 



Flies which cause myiasis in man and animals. — Some aspects of the 

 problem, F. O. Bishopp (Jowr. Econ. Ent., 8 {1915), No. 3, pp. 317-329).— A 

 review of the subject with references to the literature. 



An experiment with Stomoxys calcitrans in an attempt to transmit a 

 filaria of horses in the Philippines, M. B. Mitzmain (Amer. Jour. Trop. 

 Diseases and Prev. Med., 2 {1915), No. 12, pp. 759-763, pi. l).—One hundred 

 and fifty-four stable flies which had engorged upon a horse, the blood of which 

 showed as many as 12 microfilarisE in a single field under a low-power micro- 

 scope, were applied daily for 42 days to four normal horses. Blood examina- 

 tions for the presence of microfilaria gave negative results for all four animals. 

 The greatest death rate among the infested flies was during the flrst ten days, 

 i. e., during the period when development of the microfllarise took place in 

 their bodies. 



The effect of various chemicals on blowfly, W. F. Cooper and W. A. B. 

 Walling {Aivn. Appl. Biol., 2 {1915), Nos. 2-3, pp. 166-182) .—The authors 

 report upon experiments conducted at the Cooper Laboratory for Economic 

 Research, Watford, England, with the object of determining the insecticidal 

 value of various chemicals, a large number of which have never been actually 

 employed as insecticides. The results are presented in detail in tabular form. 

 The general summary drawn by the authors is as follows : 



" Of substances repellent to the blowfly and therefore capable of protecting 

 sheep from their ravages, the following appear to be the most suitable : Methyl 

 salicylate, p-nitranilin, picric acid, creosote, green oil, boric acid, fusel oil, pine 

 oil, alizarin oil, origanum oil, mustard oil, sod oil, iodoform, dimethylanilin, 

 quinoliu, allyl alcohol, aloin, saponin, copper carbonate, nitrobenzene, sinapis 

 oil, and aniseed oil. 



" For the application of toxic agents, a powder form has been found to be 

 very convenient and efficient, precipitated chalk forming a suitable and cheap 

 basis. The substances, applied in this form, which appear to be most toxic to 

 the blowfly larva, comprise the following: Arsenic sulphid, nitrobenzene, eu- 

 calyptus oil, methyl salicylate, cedarwood oil, p-nitranilin, ^-naphthylamin, 

 oxalic acid, borax, quinolin, allyl alcohol, picric acid, dimethylanilin, copper 

 carbonate, oil of cloves, turpentine, ^-naphthol. creosote, fusel oil, sinapis oil, 

 aniseed oil, and iodoform. Since the young larvae are much more susceptible 

 than the old, in field work, the medicated powder should be applied either 

 previous to, or in the very earliest days of, the larval stage. 



" Various vapors have been shown to be toxic to the blowfly larvae, and of 

 these the most successful are brombenzene, chloral hydrate, ethyl acetate, 

 iodin, and pyridin." 



The habits, life history, and structure of a bloodsucking muscid larva 

 (Protocalliphora azurea), A. F. Coutant {.Jour. Parasitology, 1 {1915), No. 3, 

 pp. 135-150, figs. 7). — The author reports upon studies at Ithaca, N. Y., of the 



