RESULTS OF EXPERIMENTS AGAINST THE CHICKEN MITE. 3 



these tests was 360 cubic feet, and they were as air-tight as the 

 average chicken house. All the last four treatments were of little or 

 no value. 



BANDING ROOSTS. 



A heavy anthracene oil applied on burlap strips at the ends of 

 clean roosts failed to prevent the access of mites from other places in 

 the chicken house. A few days after the application the oil hardened 

 and the mites were able to cross it. Similar bands made of sticky 

 tree-banding material were also inefficient, even when protection was 

 given from the fowls by placing boards above the sticky portion of 

 the roosts. 



MEDICATED ROOSTS. 



A wooden roost grooved beneath so as to fit tightly to a tin trough 

 running the whole length of the roost and containing a coal-tar and 

 mineral-oil mixture, when placed in an infested chicken house, 

 repelled the mites as long as the trough contained oil to keep the 

 wooden roosts permeated. This roost had no effect on the mites in 

 other parts of the house (e. g., the nest boxes). 



SUBSTANCES IN FOOD AND WATER OF FOWLS. 



The preparations following were all without value when added to 

 the food and water of fowls: Two lime-sulphur preparations, each 

 containing less than 12 per cent of calcium polysulphids and calcium 

 thiosulphates diluted at the rate of 1 to 2,150 and added to food and 

 water for 5 and 13 days, respectively; three preparations containing 

 from 33 to 35 per cent of free sulphur, added to each quart of food at 

 the rate of 1 heaping teaspoonful three times a week for 6 weeks; 

 and one preparation containing 38 per cent of free sulphur with a 

 trace of naphthalene, used as in the preceding test but for 4 weeks 

 only. 



REPELLENT SUBSTANCES SUSPENDED IN INFESTED PREMISES. 



A preparation consisting of naphthalene 14 per cent, carbon disul- 

 phid 46 per cent, and mineral oil 40 per cent, contained in a bottle 

 with a wick, suspended from the roof of a chicken house for 2 

 weeks, was without value. Fifteen grams of pyrethrum (ground 

 flowers) was suspended in a cloth bag from the top of an infested nest 

 box. This also was of no value. * 



NEST EGGS, NESTING HAIRS, AND NESTING MATERIALS. 



Prepared nest eggs, which are primarily designed to protect sitting 

 hens and remain in use during the period of incubation, were used 

 in infested nest boxes only, to determine whether they would be 

 efficient in killing or expelling the mites. 



Eight tests were made with eggs of pure naphthalene. In no case 

 was any efficiency shown. These eggs remained in the nests for 

 periods as long as 25 days. Their use in some instances caused 

 marked injury to the fowls sitting on them and appeared to interfere 

 with the health of the embryo chicks alongside them. 



Five tests were made with eggs of naphthalene and paraffin mixed. 

 These eggs were used in five infested nests for 2 hours on each of 

 3 days, at intervals varying from 6 to 8 days. None of these treat- 

 ments was of value. 



