REPORT OF STATE ENTOMOLOGIST, 1898 227 
sion, which is simply 2 gallons of kerosene and 1 gallon of sour milk 
emulsified by churning or passing through a pump. Besides being 
effective against exposed insects on plants, successful experiments on 
white grubs infesting the lawn around the capitol at Washington, D. C., 
indicate that kerosene emulsion may also be used against subterranean 
insects. Though the usual strength recommended is 1 part of the standard 
kerosene emulsion to g parts of water, Mr Marlatt has shown that 
it may be applied diluted with but 4 parts of water with almost no 
injury to growing plants (asect life. 1894. 7: 116, 117). 
Machines now on the market are said to give a reliable water and 
kerosene emulsion, the two constituents being taken from separate tanks 
in the desired proportions and emulsified mechanically as they pass 
through the nozzle. Pure kerosene is also being recommended by some 
as an insecticide that can be applied to trees in a fine spray on a bright 
drying day, without serious injury. The results heretofore obtained by 
different experimentors have been so contradictory that this treatment 
can hardly be indorsed without qualification. The safest way, as stated 
by Dr Howard, is for each man to experiment in a small way before he 
sprays many trees with this substance. 
For scale insects, whale oil soap may be applied in winter at the rate 
of 14 to 2 pounds in 1 gallon of water, as recommended by Dr Howard. 
For summer use the extreme strength is given by Dr Smith as 1 pound 
to 4 gallons of water. 
Pyrethrum, Dalmatian or insect powder, when fresh, is a valuable con- 
tact insecticide. It is usually applied in the powdered form, is not 
poisonous to man or the higher animals, and is largely used for house- 
hold insects, in greenhouses and small gardens. If desired, it can be 
diluted with flour, in which event it should be mixed and allowed to 
stand several hours before it is wanted, or it may be used in water at 
the rate of 1 ounce to 2 gallons of water, it either being boiled or 
allowed to remain some hours before application. If moistened and 
molded into cones, it may be burned with very satisfactory results, for 
the fumes, while not disagreeable to man, paralyze and kill many insects. 
Sulfur is a valuable insecticide, specially against mites. In green- 
houses it is often strewed on the heating pipes or scattered about the 
house, and in this way a mild fumigation is obtained that is quite effec- 
tive in keeping the red spider under control. It is frequently used in 
poultry houses and applied to stock.  Bisulfid of lime is said to be 
an even better remedy for mites. This is easily prepared by boiling 
together in a little water equal parts of sulfur and lime, till a brownish 
liquid results. Use at the rate of 5 pounds of sulfur and 5 pounds of 
lime to 100 gallons of water. 

@ Marlatt, C. L. Farmer's bulletin 19.1897. p. 11. 
