4 BULLETIN 1228, U. S. DEPARTMENT OF AGRICULTURE. 



An egg containing 5 per cent of naphthalene and a small quantity 

 of formaldehyde was used for 1 9 days without any effect. 



A plaster egg containing a tin receptacle holding a mixture of 

 naphthalene and sawdust was charged weekly with a mixture com- 

 posed of turpentine 54 per cent, formaldehyde 18 per cent, and 

 water 28 per cent. This egg was used for 4 weeks without any effect- 

 Two kinds of prepared nesting hair (fats 9.4 and 3.8 per cent, 

 respectively) were placed in infested jars for 8 days. These proved 

 valueless. 



Two tests were made with nesting materials of shredded bark and 

 crumbled leaves of cedar. This material was placed in clean nest 

 boxes in mite-infested premises, and sitting hens were employed. 

 In both cases mitt; infestation developed. 



TREATMENT OF THE HEN. 



Six hens were treated by rubbing into the skin 1 inch below the 

 vent a preparation containing 5.6 per cent of mercury. The fowls 

 were kept for 16 days in an infested chicken house. At the end of 

 that time the house was still infested. 



CONCLUSIONS REGARDING MISCELLANEOUS TREATMENTS. 



Of the miscellaneous methods listed above only two indicated any 

 efficiency — naphthalene fumigation and the medicated roosts. 



The tests with the former were made in a fumigatorium under 

 optimum fumigating conditions. This method would, be of value 

 where nest boxes, coops, or roosts were to be treated, but an infested 

 house could not be treated unless very nearly air-tight. The fact 

 that sulphur burnt at the rate of over 6 pounds to 1,000 cubic feet 

 was quite inefficient in a chicken house at least as nearly air-tight 

 as the average house precludes satisfactory fumigation under usual 

 conditions. *• 



The medicated roost was of some value, since it afforded protection 

 to roosting fowls for a long time, but unless the rest of the premises 

 are treated no protection is afforded fowls on the nest. 



DUSTS. 



In the dusting tests various makes of hand dusters were used. 



The following dusts were without value under natural conditions: 

 Air-slaked lime, Paris green, hellebore, calcium fluorid, sodium 

 fluorid, sodium silico fluorid, barium fluorid, barium tetrasulphid, 

 mercuric chlorid, and sulphur (refined and commercial). With the 

 exception of calcium fluorid and mercuric chlorid none of these sub- 

 stances was efficient even in jar tests. 



TOBACCO. 



Tobacco dusts containing nicotine up to 5.26 per cent (the strongest 

 percentage tested) were inefficient. 



PHENOLS. 



Dusts containing phenols up to 2 per cent were inefficient. 



