THE HOUSE FLY 57 



does reach them, when sprayed over the manure as it is 

 being turned over, it is necessary for it to be strong in order 

 to kill the fly maggots, as they are very tenacious of life, 

 and the insecticide which is capable of killing them must 

 be about four or five times as strong as that used against 

 other kinds of insects. 



When paraffin emulsion, creosol preparations, and 

 chloride of lime are used freely and the rubbish heap 

 impregnated throughout, the fly maggots will all be killed. 

 Another plan is to poison the maggots by mixing arsenate 

 of lead, Paris green, &c., with the manure or garbage. 

 When thoroughly applied and in sufficient quantity, these 

 chemicals will effectively kill the maggots, but they must 

 be handled by an intelligent person who thoroughly under- 

 stands how to use them. The disadvantage of their use 

 is that they are expensive when used freely, and that they 

 are either highly inflammable, corrosive, or poisonous. 



Careful experiments by Professor S. A. Forbes, of Illinois, 

 have shown that one of the cheapest and most effective 

 ways of chemically treating manure or garbage is to 

 thoroughly spray it with a solution of sulphate of iron. 

 A gallon of water in which 2 Ib. of the sulphate has 

 been dissolved will kill all the fly maggots in 15 Ib. 

 of manure, if it is turned over while being sprayed. A 

 gallon of this solution for each horse per day is necessary 

 to prevent the breeding of fly maggots in the manure or 

 to kill them if present. 



The contents of garbage boxes, cans, and bucket privies 

 should be sprinkled every day or two with a solution of 

 sulphate of iron of 2 Ib. to a gallon of water. The 

 operation could be performed by means of an ordinary 



