81-i Popular Editions of Station Bulletins. 



and (2) to destroy the larvae after petals drop to reduce the num- 

 bers of insects which will mature in the ground. 



The period for effective spraying against the adult or winged 

 thrips is during the time when the buds are swollen and partly 

 open and until they are entirely opened at the tips. The first 

 treatment should be made as soon as the thrips become numerous 

 on the trees. The number of the applications required will de- 

 pend on the thoroughness of the treatments. The grower should 

 spray on successive days or every few days until the thrips are 

 reduced to comparatively few individuals. Two and certainly 

 not more than three sprayings are required to afford efficient pro- 

 tection to the trees from the adult thrips. Especially hard to kill 

 are the insects within the buds, as they are often hidden, and it 

 is difficult to force the spraying mixture in between the growing 

 structures of the bud. While it is not possible to reach all of 

 these, many of them may be destroyed by careful work in apply- 

 ing the sprays. By successive applications severe injury may be 

 largely or entirely prevented. To secure the greatest benefits 

 from the treatments, apply the spraying mixtures in liberal quan- 

 tities as a rather coarse driving spray, holding the nozzle fairly 

 close to the buds in order to force the liquid into the ends of the 

 buds. The " angle nozzles " of the large chamber type or nozzles 

 set on an angle to the extension rod, maintaining a pressure of 

 not less than one hundred fifty pounds are preferable'. 



The larvae may be seen in large numbers as small, whitish crea- 

 tures in the calyx cups, on pears especially (see title page illus- 

 tration), when they are well exposed to spraying because of the 

 open nature of" the blossom ends of the young fruits. One or two 

 careful sprayings will practically free the trees of the insects. In 

 making an application both surfaces of the leaves and the calyx 

 ends of the young fruits should be thoroughly wetted by the 

 liquid. Spraying for the larvae is important because it will 

 greatly reduce the numbers of the insects which seek shelter in the 

 groimd until the following spring. 



(Plate XXXV was also given in this popular edition.) 



