14 FARMERS' BULLETIN 851. 



fly that it is perfectly feasible for cities and towns to reduce the 

 numbers of these annoying and dangerous insects so greatly as to 

 render them of comparatively slight account. 



CONSTRUCTION AND CARE OF STABLES. 



In formulating rules for the construction and care of stables and 

 the disposal of manure the following points must be taken into con- 

 sideration. In the first place, the ground of soil-floor stables may 

 offer a suitable place for the development of fly larvae. The larvae 

 will migrate from the manure to the soil and continue their growth 

 in the moist ground. This takes place to some extent even when the 

 manure is removed from the stables every day. Even wooden floors 

 are not entirely satisfactory unless they are perfectly water-tight, 

 since larvae will crawl through the cracks and continue their develop- 

 ment in the moist ground below. Water-tight floors of concrete or 

 masonry, therefore, are desirable. Flies have been found to breed in 

 surprising numbers in small accumulations of material in the corners 

 of feed troughs and mangers, and it is important that such places be 

 kept clean. 



FLY-TIGHT MANURE PITS OR BINS. 



The Bureau of Entomology for some years has advised that manure 

 from horse stables be kept in fly-tight pits or bins. Such pits can be 

 built in or attached to the stable so that manure can be easily thrown 

 in at the time of cleaning and so constructed that the manure can 

 be readily removed. The essential point is that flies be prevented 

 from reaching the manure, and for this reason the pit or bin must be 

 tightly constructed and the lid kept closed except when the manure 

 is being thrown in or removed. The difficulty has been that manure 

 often becomes infested before it is put into the container, and flies 

 frequently breed out before it is emptied and often escape through the 

 cracks. To obviate these difficulties a manure box or pit with a 

 modified tent trap or cone trap attached is desirable. 



In order to retain the fertilizing value of manure to the greatest 

 extent it is advisable that air be excluded from it as much as pos- 

 sible and that it be protected from the leaching action of rains. This 

 being the case, there is really no necessity for covering a large por- 

 tion of the top of the box with a trap, but merely to have holes large 

 enough to attract flies to the light, and to cover these holes with ordi- 

 nary conical traps, with the legs cut off, so that the bottoms of the 

 traps will fit closely to the box. The same arrangement can be made 

 where manure is kept in a pit. 



FREQUENCY WITH WHICH MANURE SHOULD BE REMOVED. 



Another point must be considered in deciding the question as to 

 how often the manure should be removed. In this connection it 

 should be borne in mind that when the larvae have finished feeding 



