404 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 12 



Arsenical Dip (B. A. I. formula) : Made about three months, exact strength at 

 time used not known. Fifteen days after treatment no live mites found. 



Kerosene emulsion: Two gals, kerosene, ^ lbs. soap, 1 gal. water. Dilution, 

 1 to 10. Thirty-nine days after treatment no live mites found but fowl's skin was 

 injured by burning. 



Sulphur and sodium fluoride: Two-thirds oz. NaF., 2 ozs. sulphur, 1 gal. water. 

 Five days after treatment one live mite found. A later observation should have 

 been made. 



Sodium fluoride, soap and water: Three-fourths oz. NaF., § oz. whale oil 

 soap, 1 gal. water. Sixteen days after treatment live mites found. 



Sodium fluoride, sulphur, soap and water: Two-thirds oz. NaF., 2 ozs. sul- 

 phur, soap (enough to make the water soapy), 1 gal. water. Sixteen days after 

 treatment no live mites found. 



In these experiments one hen was used in each experiment. The 

 birds were held under the solution about one minute, during which 

 time the feathers were thoroughly ruffled and the heads ducked two 

 or three times. 



Summary of Preliminary Experiments in Depluming Mite Control 



Substance Used All Mites Killed Injurious Effect 



Lime-sulphur Yes None 



Potassium sulphuret No None 



Tobacco-sulphur Yes None 



Dry sulphur Yes Negligible 



Arsenical dip Yes None 



Kerosene emulsion Yes Injurious 



Sulphur and sodium fluoride No None 



Sodium fluoride, sulphur and soap Yes None 



Of these substances, lime-sulphur, tobacco-sulphur, dry sulphur, 

 B. A. I. Dip, and sodium fluoride, sulphur and soap were effective. 

 Inasmuch as we have found sodium fluoride so effective against lice 

 we thought it advisable to try on a larger scale to see if both the lice 

 and depluming mite could be eradicated at one treatment. 



June 30, 1917, 48 fowls infested with hce and the depluming mite 

 were dipped in a solution of sodium fluoride (chemically pure) | oz., 

 sulphur 2 oz., soap (laundry) | oz. (about), water 1 gal. A number of 

 feathers were plucked from the treated fowls 27 days, 55 daj'-s, and 

 about 5 months, 6| months, 11 months, 1| years after treatment and 

 at no time were living mites or lice found. 



A warm day was selected to treat the fowls and there was no injury 

 to them. The experiment may, therefore, be considered, a complete 

 success. A subsequent experiment on 120 hens infested with deplum- 

 ing mites, treated June 5, 1918, in the same way as in the above experi- 

 ment and observed until January 17, 1919, verified the results of the 

 previous experiment. 



