242 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 6 



nursery in which the work is being carried on finds that while he has 

 been able, at great expense, to prevent serious injury from the pest, 

 he has not been able to control it completely. In view of the fact 

 that the pest seems to pass the winter in the adult stage and arrives 

 in the nurserj^ to deposit eggs soon after the trees begin to grow, it 

 occurred to the writer that a very thorough application of a contact 

 wash in the spring to destroy the first brood of young might have 

 a far-reaching effect upon the pest later in the season. With this 

 in view a series of experiments with different washes was undertaken 

 and from a comparative test of some eight or ten of these, it was found 

 that the young nymphs could be readily destroyed with an oil wash. 

 One of the commercial brands of miscible oils gave the best results. 

 Probably the same results could be obtained by the use of a home- 

 made kerosene emulsion, but this wash was not included in the com- 

 parative test this past spring. The kerosene emulsion has been the 

 standard wash with this nursery firm for a number of years and the 

 foreman found that it did not seem to be quite as effective as the misci- 

 ble oil. 



In order to control this first brood it is necessary to make three 

 or four applications at intervals of from three to six days since the 

 nymphs of the first brood do not appear at the same time. The first 

 brood seems to be drawn out over two or three weeks. After carefully 

 applying contact washes for this brood, spraying operations should 

 be discontinued. The washes under consideration had little or no 

 effect upon the stray adults which were found in the nursery during 

 the application and spraying operations are too expensive to repeat 

 throughout the summer at the necessary intervals to catch the nymphs 

 before they become winged. 



Following the early spraying this year a machine was run at inter- 

 vals of three or four days with a view of catching as many of the winged 

 adults as possible. This trap is built on the sticky shield plan, mounted 

 on wheels and so adjusted as to enclose two rows of trees. The sticky 

 shields extended forward to a point slightly in advance of the horse 

 and are roofed over behind and sufficiently high on either side to 

 prevent the escape of many of the insects. In this way the horse 

 acts as an agitator and the back part of the machine is closed by sus- 

 pending gunny sacks thereby preventing the escape of any great number 

 of insects in that direction. 



In the experiment carried on during the summer it was found that 

 so many of the hoppers, tarnished plant bugs, and other insects of this 

 type were caught upon the sticky surface of the machine that it was 

 usually necessary to scrape and re-paint the machine twice each day 



