REPORT OF STATE ENTOMOLOGIST, 1898 227 



sion, which is simply 2 gallons of kerosene and i 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 i part of the standard 

 kerosene emulsion to 9 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 [^Insect 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 if to 2 pounds in i gallon of water, as recommended by Dr Howard. 

 For summer use the extreme strength is given by Dr Smith as i 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 i 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 

 hquid results. Use at the rate of 5 pounds of sulfur and 5 pounds of 

 hme to 100 gallons of water. 



a Marlatt, C. L. Fartner^s bulletin 19. 1897. p. 11. 



