ON THE HOUSE-FLY INVESTIGATIONS. 465 



18. Fly Investigations Keports. — II. Trials for CJatching, 

 Repelling, and Exterminating Flies in Houses, 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 Lefeoy, 

 November 9, 1915.] 



The trials were made at a country residence in Kent during 

 August and SejJtember. House-llies were particularly numerous 

 in the kitchen qiiarters and in an outhouse where poultry-food 

 was prepared and stored. The living-rooms of the house were 

 practicaUy free from flies. 



An inspection was made to ascertain whether any breeding- 

 grounds existed on the premises. It was found that farmyard 

 manure dumped into a manure-tip produced a large number of 

 flies, though it was clear that the main source was beyond the 

 control of the householder. Pigs were kept on this manure, 

 which was allowed to accumulate for six weeks before being 

 moved and stacked on some land a few yards away. 



No steps had been taken to check the increase of flies, and the 

 situation offered scope for testing under normal conditions the 

 remedies which from experimental investigations were most 

 promising. 



Measures were taken : 



1. To check the breeding of flies by treating the farmyard 

 manure : — 



(«) In the manure-tip by watei'ing the surface every four 

 days with Westoran, in the strength of one part to 

 twenty parts of water. 



(6) Stacked for use in the garden by dressing the surface 

 with green oil and soil, in the proportion of one part 

 oil to forty parts of soil per 100 square feet of surface. 



2, To destroy flies by poisoning and by attracting to traps. 



Trial I. — Trapping. » 



Balloon traps baited with (1) casein, sugar, and stout ; 



(2) ,, ,, banana ; 



(3) ,, ,, water 

 gave the following results : — 



* Communicated by Prof. U. Maxwell Lefeoy, M.A., F.Z.S. 



Proc. Zool. Soc— 1916, No. XXXIII. 33 



