RESULTS OF EXPERIMENTS AGAINST THE CHICKEN MITE. 7 



Table 1 indicates that several well-known contact insecticides used 

 at strengths ordinarily efficient against most sucking and some 

 chewing insects proved inefficient against the chicken mite. 



In a number of tests, sodium hypochlorite at a dilution weaker than 

 0.94 per cent (" available chlorine") was in all cases inefficient. 



Formaldehyde, 4 per cent, did not give a killing that could be 

 termed efficient and was objectionable to the operators. 



Lime-sulphur and sodium sulphur, well-known acaricides, proved 

 inefficient, the former even at dormant orchard strength. 



Free nicotine at a strength of 0.07 per cent in combination with 

 whale-oil soap, 4 pounds to 100 gallons, proved but slightly efficient, 

 while at a strength of 0.12 per cent with a similar proportion of whale- 

 oil soap it was moderately efficient. 



Extract of derris, 16 per cent, diluted to 1 to 1,000 and 1 to 500, 

 with the addition of whale-oil soap, 4 pounds per 100 gallons, was 

 inefficient. 



Whale-oil soap, 1 pound to 1 gallon and at twice this strength, 

 showed some efficiency but was hardly satisfactory. 



OILS. 



Tests were made with three types of oil preparations: (1) Straight 

 oils, (2) mechanical mixtures of two oils or solutions of another type 

 of substance (e. g., naphthalene) in an oil, and (3) oil emulsions. 



Preparations of the first type included kerosene, gasoline, and 

 coal-tar creosote oil. Pure kerosene was used in three chicken 

 houses. In one house it was efficient; in the two others only moder- 

 ately so. Gasoline was of little value. A coal-tar creosote oil (sp. 

 gr. 1.062 at 30° C.) was quite efficient. It appears certain that all 

 the heavier oils, undiluted, would be efficient, but the lighter oils, 

 perhaps owing to too rapid evaporation, are less efficient. 



The tests made with mechanical mixtures are given in Table 2. 



Table 2. — Results of tests with oil mixtures and mixed oils against the chicken mite. 



No. 



of 



test. 



Materials. 



Strength, 



Dilution. 1 



Result. 



Paradichlorobenzene . 



....do 



....do 



Naphthalene 



....do 



....do 



Wood creosote oil 



Phenol 



Crude carbolic acid. . . 



....do 



/Cresol 



\Kerosene 



/Coal-tar creosote oils. . 



\Phenols 



/Carbolineum 



\ Kerosene 



f Carbolineum 



(Kerosene 



/ Carbolineum 



\Kerosene 



/Carbolineum 



\ Kerosene 



/Carbolineum 



\ Kerosene 



/Carbolineum 



(Kerosene 



Per cent. 



100.0 



100.0 



100.0 



100.0 



100.0 



100.0 



100.0 



100.0 



100.0 



100.0 



20.0 



80.0 



86.8 



13.2 



50.0 



50.0 



33.3 



66.7 



25.0 



75.0 



20.0 



80.0 



10.0 



90.0 



7.0 



93.0 



960 grams in kerosene 4 gallons . . . 

 480 grams in kerosene 4J- gallons . . 

 960 grams in gasoline 4J gallons. . . 

 960 grams in kerosene 5 gallons . . . 

 480 grams in kerosene 4 gallons . . . 



240 grams in gasoline 2 gallons 



1 to 8 in whitewash 



do 



1 to 9 in whitewash 



1 to 11£ and 1 to 15 in whitewash . 



i-None 



....do. 

 ....do. 



...do. 

 ...do. 



- do. 



• do. 



}•• 



.do. 



Moderately efficient. 

 Somewhat efficient. 

 Inefficient. 

 Somewhat efficient. 



Do. 



Do. 

 Efficient. 



Moderately efficient. 

 Efficient. 

 Inefficient. 



Efficient. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 

 Somewhat efficient. 



1 In tests 1 to 6, inclusive, the paradichlorobenzene and the naphthalene were dissolved in the oils. 



