88 NEW YORK STATE MUSEUM 



tact insecticides, such as tobacco preparations, whale oil soap 

 solutions, kerosene emulsions or even dilute preparations of 

 some of the commercial petroleum compounds now on the 

 market under various trade names. 



Tobacco preparations of various kinds have long been used 

 for the destruction of plant lice, though some experience is 

 necessary to secure the proper dilution, owing to the variabil- 

 ity of waste tobacco products from which decoctions are usu- 

 ally prepared. There are now on the market a number of 

 ready-made tobacco extracts. A most promising one is known 

 as black leaf extract. It has given very good results in an 

 experimental way, even when diluted with 60 parts of water. 



The experience of the last season or two has also demon- 

 strated the feasibility of employing a dilute lime-sulfur wash. 

 Several practical orchardists have used the better grades of 

 commercial lime-sulfur washes, diluted with 40 parts of water 

 and adding thereto two pounds of lead arsenate to each 50 

 gallons, making the application at the proper time for con- 

 trolling codling moth. It has been found effective, so far as 

 the last named pest is concerned, extremely serviceable in de- 

 stroying plant lice and of great value as a fungicide. It is 

 possible that this combination or some modification may ulti- 

 mately take the place of the poisoned bordeaux mixture and 

 solve for all time the problem of controlling plant lice out- 

 breaks, since one thorough spraying with a contact insecticide 

 just after the blossoms fall, would probably obviate the neces- 

 sity of any further treatment for plant lice, particularly if this 

 was an annual practice. 



The insecticide to be employed must depend somew^hat upon 

 conditions. There is no doubt but that a thorough application 

 of a whale oil soap solution, used at the rate of one pound 

 to six or seven gallons of water, is very effective. Even a 

 strong suds of ivory soap, approximately a five cent cake to 

 eight gallons of water, is extremely serviceable and may be 

 employed upon a large variety of plants without injury. The 

 standard kerosene emulsion, diluted with 9 to 15 or more parts 

 of water, is equally valuable. Ready-made oil emulsions, re- 

 quiring dilution only before application, are on the market 

 and are much more convenient for the small fruit grower. 



The essential in all these cases, so far as plant lice are con- 

 cerned, is to make the application before the foliage has be- 



