57 



as poisons for general use. House-fiies showed no colour preference 

 either in the case of foods, coloui'ed lights or coloured fabrics. The 

 optimum temperature of food for house-flies was found to be between 

 38° and 48° C. (99°-118° F.), the maximum between 55° and 58° C. 

 (132° and 136° F.), and the mininmm between 10°-13° C. (50° and 

 55° F.). 



As regards humidity, it was not possible to draw very definite 

 conclusions^ but the general impression was that most foods, especially 

 when very moist, were more attractive to house-flies on dry than 

 on wet days. Flies, and particularly blow-flies, were able to stand 

 a greater amount of moist than of dry heat. Blow-flies bred in a 

 greenhouse throve if the air was kept moist, but died if it became 

 dry. This also applies to the maggots, but was more marked in the 

 case of adults. Without water, house-flies were able to live only 

 one or two days. Food covered with glass was less attractive than 

 the same food covered with mushn. Painting over the eyes of flies 

 indicated that they were still able to tell attractive from repellent 

 foods, and are evidently guided more by the sense of smell than by 

 that of sight. 



Eggs of Fannia were kept under observation in order to determine 

 the duration of the early stages. From eggs laid on a banana skin 

 on 13th August, maggots hatched on 14th to 17th August. They 

 began to pupate on 25th and 26th August and had all pupated by 

 4tli September. Adults began to emerge on 7th September, the 

 maximum emergence being on 23rd and 24th September, and all 

 had emerged by 3rd October. 



Waterston (J.). Notes on some Blood-sucking and other Arthropods 

 (except Culicidae) collected in Macedonia in 1917. — Bull. Entom. 

 Research, London, ix, no. 2, September 1918, pp. 153-155. 



A list is given of parasitic or noxious Arthropods, particularly of 

 those affecting man, observed by the author in the course of mosquito 

 control work in Macedonia, with notes respecting the locality where 

 found and the host attacked. 



M'usca domestica was particularly troublesome in one area during 

 late October and early November. Owing probably to heat the flies 

 came readily to baits of sweetened formalin and water and many 

 were Icilled in this way, while burning, swatting, trapping and spraying 

 disposed of many more. For spraying an aqueous solution of 5 per 

 cent, formalin had been used. As a substitute a mixture was made 

 of \ lb. bar-soap boiled till dissolved in | gal. water and then | gal. 

 paraffln slowly added and | pint mixed ketones incorporated in the 

 same way. This was effective but the ketones smelled strongly and 

 discoloured wood- surfaces. The ketones were then omitted and 1 gal. 

 paraffin used in the mixture. This killed the flies ahnost instan- 

 taneously and none that were touched escaped. Even diluted to half 

 strength this mixture was effective. It is considered that it may 

 be worth while to investigate the constitution of a suitable emulsion 

 spray for flies and particularly to ascertain what should be the 

 minimum oil content of such a mixture. 



