October, '19] ABBOTT: NAPHTHALENE VS. CHICKEN LICE 



399 



containing more than 10 per cent of naphthalene should be applied 

 with considerable caution. 



Birds that were dusted with 60 per cent or 100 per cent naphthalene 

 were killed when the powder was thoroughly rubbed into the feathers, 

 but were not permanently injured when lightly dusted. 



Naphthalene Sprinkled over the Fowls While at Roost 



Since a method of controlling chicken lice which did not necessitate 

 catching and treating each bird individually would be of great value 

 to the poultryman, a series of tests was made to determine the effects 

 of treating the fowls while they were on the roost. In these tests 

 finely powdered naphthalene was sifted or sprinkled over the backs 

 of lousy hens after they had settled down on the roost at night,care 

 being taken to disturb them as little as possible. Tests 1 to 3 were 

 made in cages in the greenhouse and Tests 4 to 9 in small hen houses. 



Table II gives the results of these tests. 



Table II. 



The Results of Sprinkling Naphthalene over the Backs of Lousy Hens While 

 They were on the Roost at Night 



» Two hens about as badly infested as before treatment. 

 ' One hen about as badly infested as before treatment. 

 ' Dusted on two successive nights. 



These data show that 32 out of 35 hens used were greatly benefited 

 by the treatment, it being estimated that from 80 to 100 per cent of 

 the lice had been killed or repelled. In Test 6 the one bird not bene- 

 fited was known to have fluttered and shaken herself just after the 

 naphthalene was applied. In Test 3 it was noted that the hens were 

 very uneasy and it seems probable that the two which remained in- 

 fested with lice also shook off tlie powder before settling down on the 

 roost. 



Although the lice were not completely eradicated a very material 

 reduction in the number present was observed on over 90 per cent of 

 the fowls and the results are about as good as would be obtained by 

 dusting as it is ordinarily done. 



It is not claimed that this method of treatment has been given an 



