12 



THE PEAR THRIPS. 



Stems would become dry during the four days of confinement, and 

 almost invariably no young thrips issued. The egg seemed to need 

 the moisture for its preservation and development, and the young 

 thrips must have very tender and pliable tissue in order to be able to 

 emerge. The young insect is almost transparent, and when food is 

 taken in the green (chlorophyll) particles can be seen through the body 

 wall. From the beginning the body growth is very rapid, and a few 

 -^^insects are capable of doing great injury, so voracious are they in 

 feeding. 



Young thrips feed almost entirely on tender foliage and fruit, and 

 their manner of feeding is much the same as that of the adult insect, it 



Fig. 6. Bartlctt Pear. Dead blossom clusters 

 conspicuous; one late straggling blossom 

 left untouched, the adult thrips having all 

 left the tree. Leaves deformed. 



Fig. 7. Pear branch, showing the rolling and the 

 cup-shaped deformities of the leaf; injury 

 caused by the feeding of young thrips. 



being a rasping and sucking combination. They usually prefer the 

 tenderest foliage, such as terminal buds, but often, as in the cherry, 

 they attack the under side of leaves near the prominent veins, causing 

 them to become much contorted and ragged, and full of holes. 



Young thrips are perfectly helpless creatures and subject to the 

 'attacks of other insects, bvit they seem to be able to protect themselves 

 . in a remarkable way. They are commonly secreted in the terminal 

 tips of the branches, but in some case's they seem to take advantage of 

 certain tendencies in the growth of the plant on which they happen to 

 feed. Newly opening pear or apple leaves have a tendency to roll from 

 the sides inward. Young thrips find this inner protected surface a 

 most desirable place for food and shelter, and in feeding, the upper leaf 



