54 NEW YORK STATE MUSEUM 



part of May or early in June, and, as in the case of the elm leaf beetle, 

 it is advisable to throw the poison on the under surface of the leaves, 

 since the very young caterpillars rarely break the upper epidermis. The 

 same treatment is also very effective in the case of tent caterpillars, and 

 in each case will be found valuable in proportion to its thoroughness. 

 The aim of the operator should be to cover every leaf evenly with a mist 

 like coating of the poisonous mixture. Spray till the leaves begin to drip 

 but no more. 



Proper apparatus. In order to do this work successfully one must 

 possess a force pump capable of throwing a stream some distance, 

 a number of feet of hose and a nozzle which will discharge a rather fine 

 spray. There must also be something to hold the poisonous mixture, 

 while a ladder facilitates the work greatly. 



One of the best arrangements for hand work is most probably found 

 in the spraying outfit mounted on wheels, so that it can be readily moved 

 from place to place (plate 4). In most cases this takes the form of a box 

 or barrel to which a force pump is firmly attached, and either provided 

 with wheels or else designed to be placed in a wagon. In spraying tall 

 trees 25 to 50 or more feet of -J- or ^^ inch hose should be provided, 

 while the addition of a brass or iron and brass extension 10 to 25 feet 

 long adds materially to the value of the apparatus. It is also necessary 

 to have a good nozzle which will not clog, but will produce a fine spray and 

 which can be quickly adjusted to throw a coarse spray some distance if 

 necessary. Such an outfit is of great service to any individual having con- 

 siderable spraying to be done and undoubtedly it could be used to 

 advantage by those desiring to make a business of spraying in a small 

 way, as for example the treating of trees here and there for those in cities 

 desiring their trees sprayed and not willing to purchase the necessary 

 apparatus. 



In the extended work against this insect conducted by cities and 

 villages, it is desirable to have apparatus that will admit of more rapid 

 work. This has led to the refitting of retired fire engines and the design- 

 ing of more or less cumbersome outfits for this purpose. In all cases these 

 makeshifts have been successful, though they are not so satisfactory in 

 operation as those specially fitted for the purpose. Probably the best 

 apparatus yet designed for spraying trees is that constructed under 

 the direction of Dr E. B. Southwick, entomologist of the depart- 

 ment of public parks of the city of New York, which is the 

 form used in Albany. The whole outfit is represented in plate 5. It 

 consists of a " Daimler" gasohne motor operating a Gould force pump — 

 the motor and pump weighing but 300 pounds can be placed in the 



