508 OTHER BLOOD-SUCKING FLIES 



most important of this group of biting flies, preventive measures 

 are fairly easy. The drying out, burning, or burying of waste 

 vegetable matter, such as piles of weeds, wet hay, lawn dippings, 

 waste vegetable matter in garbage heaps, etc., eliminate the main 

 breeding places. Poorly constructed hay stacks, around which 

 there is a good deal of loose hay which becomes soggy and de- 

 cays, are breeding centers for the flies. Stacks, when needed, 

 should be constructed with evenly rounded top and vertical sides; 

 but a better way, when possible, is to bale hay or straw and store 

 it in dry places. Manure especially when mixed with straw is 

 utilized by stable-flies in lieu, of better breeding places, but the 

 principal manure-breeder is the housefly, Musca domestica. Ac- 

 cording to recent work by the U. S. Department of Agriculture, 

 manure can be treated in such a way as to destroy the young 

 stages of stable-flies and houseflies without injuring its fertilizing 

 value. A mixture of ten oz. of borax and 12 oz. of crude calcium 

 borate (colemanite) is applied to ten cubic feet (eight bushels) 

 of manure, the manure being then sprinkled with two or three 

 gallons of water. A still better substance to apply is hellebore 

 powder, one-half lb. in ten gallons of water to eight bushels of 

 manure. An excessive quantity of the powder has no injurious 

 action on the fertilizing power of the manure, as has an excess of 

 borax. 



