HOUSE-FLY INVESTIGATIONS. 



473 



not seen emerging from the Tar- oil -treated heaps, and these 



were covered 

 numbers. 



Tar Oil and 



Pi/ridene ; 



Top and Under. 



Flies emerged, 

 no pupse present 

 in the soil uiider- 

 neatli. 



with muslin. Flies emerged later in small 



Tar Oil and, 



Fyridene ; 



Surface only. 



Few flies emerged, 

 pup;e found in 

 the soil under- 

 neath. 



Mineral Oil and 



Fyridene ; 

 Top and Under. 



Many flies 

 emerged, no 

 pupae in the 



soil. 



Mineral Oil and 



Fyridene ; 



Surface only. 



Flies emerged, 

 some pupa3 in 

 the soil. 



Results show that the Tar oil prevents the maggots from 

 migrating into the soil below the manure-heap. While forming 

 a barrier to larvae, and acting as a deterrent to flies, it does not 

 prevent flies which emerge from pupte present in the manure 

 from escaping through gaps provided by the straw of long 

 manure. 



N.B. — Maggots placed on soil mixed with (1) Green Tar oil, (2) Neutral 

 Blast-ftr'naee oil burrowed into it away from the light, and were 

 dead in ten minutes. 



lY. Four manure-heaps, each on a base 6g feet square, rising 

 3 feet in the centre to a point, were treated with : — 



Neutral Blast-furnace Oil.-s 



Blast-furnace Creosote. > \ gallon with 20 gallons soil. 



Green Tar oil. -' 



Control. 



The treated soil was spread evenly over the heaps. Maggots 

 were placed in each and the temperatures recorded. In areas of 

 about 95° F. the larvae were dead in all but the Control heap. 



Results. 



In five days the Control heap was infected while the treated 

 heaps remained immune. Observations showed that conditions 

 were favourable to breeding, but that flies were repelled from the 

 treated heaps. 



V. Five heaps, each on a base 7 feet square, rising 3 feet to a 

 top 3 feet square, were treated with : — 



Neutral Blast-furnace oil. 1 



IMast-furnace Creosote. 



Green Tar oil. 



Miscible oil and Fyridene. J 



Control. 



Result s. 



In four days maggots were found in the heaps treated with 

 Blast-furnace Creosote and Miscible oil and Fyridene. These 

 two stacks were destroyed. For ten days no maggots were 

 found in the other two, although conditions such as moisture, 



Y\ gallon to 10 gallons soil. 



