170 SANITARY ENTOMOLOGY 



The use of larvicides and other chemical compounds in barn yards is 

 usually inadvisable. Thorough cleaning ordinarily will handle the situa- 

 tion. Crude oil has been used in yards where considerable numbers of 

 horses are kept to permit firm packing of the ground and keep down 

 dust in dry weather. Borax, either dry or in solution, may be used in 

 breeding places which can not be cleaned thoroughly. Poultry and hogs 

 consume large numbers of larva^ and pupa* and scatter the manure so it 

 will dry out rapidly. These agencies should not be depended upon, how- 

 ever, to effect control. 



The employment of conical fly traps about stables and dairy bams, 

 if they are kept properly baited, will aid in reducing the number of house 

 flies. Cheap molasses and water (1 to 3), or milk curd, brown sugar and 

 water in equal parts form good baits. The latter, if kept moist, will 

 remain attractive for two or three weeks. It is comparatively unattrac- 

 tive for the first few days. Hodge type window traps aid in reducing the 

 house fly and stable fly troubles within bams if the barns are closely 

 built and the other windows darkened or screened. 



FLY CONTROL IN PIG LOTS AND PENS 



The hog has been looked upon from time immemorial as a filthy ani- 

 mal and he is usually compelled to live in surroundings which would never 

 be tolerated for any other beast. 



One of the special problems which confronts the municipal and the 

 army sanitarian is the utilization on a large scale of city and camp 

 garbage by hog feeders. There appears to be no more economical way 

 of disposing of garbage than by this method, but the conditions under 

 which the feeding is to be done must be given strict attention by sani- 

 tarians. In the vicinity of nearly every city and large army camp is 

 located one or more of these garbage feeding plants, the number of hogs 

 ranging from a few hundred to several thousand. For the most part the 

 garbage is sold to feeders under annual contract. Army garbage at 

 least is supposed to be free from glass, cans, coffee grounds, and liquids. 

 The contractors furnish the garbage cans, remove the garbage daily and 

 return empty cans which arc supposed to be thoroughly cleaned. If the 

 orange, grapefruit, and lemon peels could be eliminated from the garbage, 

 the mass of material not eaten by the hogs would be materially reduced. 

 Garbage feeding plants should be operated under approximately the 

 following set of iiiles : 



1. Location of Feeding Stations. — Station should be located as far 

 from habitations as possible and also well removed, two miles or more, from 

 the city limits or the precincts of an army camp. Our recent experiments 

 show that flies of various species, including the house fly, travel thirteen 



