ox THE HOTTSE-FLY INVESTIGATIONS. 469 



19. ¥\y . Investigiitions Reports. — Til. Investi(>-atioiis into 

 Stable Manure to check the Breeding of Hoiise-Flies, 

 made during the year 1915 for the Zoological Society 

 of London. By Winifred H, Saunders *. 



[Received March 19, 1916 : Preliminary report read by Prof. H. Maxwell Lefrot, 

 November 9, 1915.] 



Introduction. 



An extensive series of experiments was made in Jnne a.nd 

 July for the purpose of finding a treatment for fresh stable 

 manure, which would be effective in checking the breeding of 

 House-flies, and which could be safely employed for agricultural 

 purposes. 



Owing to the increased price of borax, which before the war 

 wa.s the only substance in use for the purpose, the need for a 

 treatment at a lower cost was pi-essing for military purposes, for 

 farmers, horticulturists, and manure contractors. 



Many practical obstacles arose in working out the solution of 

 this problem. 



Although many tons of manure were accumulated in artillery 

 and ca.valry camps, it was impossible to get a sufficient quantity 

 conveyed to convenient trial-grounds owing to the difficulty of 

 transport. A small amount was purchased, and, later, facilities 

 were granted at the Army Veterinary Hospital, Woolwich, and 

 on market-garden prenuses at Brentford, where stable manure 

 was dumped. Experiments on manure, to test the action of 

 various liquids upon flies and maggots, ^vel•e cariled out at 

 Woolwich and a.t Brentford, and those on plants at the Ptoyal 

 Horticultural Society's Gardens, Wisley, at Messrs. Sutton's, 

 Reading, and at the Horticultural College, Swanley. 



This work on mannre treatments was suggested and designed 

 by Professor Maxwell Lefroy, under whose guidance all the 

 experiments have been cai^ried out. 



A. Manurial Experiments. 



Experiments on fresh stable manure were made along two 

 lines : — 



1. To test the action of va.pourisable liquids upon maggots 



present in the manure. 



2. To test the action of substances as repellents to flies 



when applied to the surface of maniu'e heaps. 



Experimental heaps of definite sizes and shapes were con- 

 structed, and the strength of each application was in proportion 

 to the cubic area of the manure. 



* Communicated by Prof. H. Maxwell Lefkot, M.A., F.Z.S. 



