JOURNAL OF ENOCOMIC ENTOMOLOGY 



[Vol. 12 



Naphthalene was tested in three ways: 



1. As a dust in various percentages. 



2. Sprinkled over the backs of the fowls while they were on the 

 roost at night. 



3. In the form of nest eggs. 



Naphthalene as a Dust 



In these experiments the chickens were held by one person and 

 dusted by another. The powders were applied by means of a hand 

 dust gun or shaker and, unless otherwise noted, were well rubbed into 

 the feathers. The fowls were confined in cages or small chicken houses 

 and were carefully examined one or two days after treatment when 

 the percentage of lice killed or repelled was estimated. Various finely 

 powdered materials, such as lime, charcoal or flour were used on car- 

 riers, it having been proved that these materials were not effective 

 against lice. 



Table No. 1 gives the results of these dusting tests. 



Table I. The Results of Tests with Naphthalene Used as a Dust Against Chicken Lice 



These data show that a powder containing 5 per cent or less of 

 naphthalene is of no value against chicken lice, while 10 per cent or 

 more is very effective. 



In all cases where 10 per cent or more of naphthalene was used and 

 well rubbed into the feathers, the fowls were slightly injured. The 

 lower percentages seemed to partially stupefy the fowls and to tem- 

 porarily deprive them of the free use of their legs. They would slump 

 down on the ground with their eyes closed and frequently fall over on 

 one side. When aroused they would run about and then settle down 

 as before. These symptoms would last for five or ten minutes and 

 then recovery seemed to be complete, as no ill effects were noticed 

 after this. It is apparent, however, that until the exact character 

 and the amount of this injury has been accurately determined, powders 



