134 CROP PRODUCTION 



Insect Enemies 



The Pear is also subject to attack by many insect 

 pests; the CodHng Moth, the Plum Curculio, and the San 

 Jose Scale have life-histories on pears very similar to 

 those upon apples. Various borers and bark-beetles 

 also attack pear trees as they do apple trees. -The leaves 

 are fed upon by the Pear Slug, a small two-brooded 

 insect that is readily killed by spraying with arsenates. 



The Pear Psylla is a small insect that is sometimes 

 locally injurious. It is a tiny creature, related to the 

 aphides. It winters over as an adult, often in the shelter 

 of loose bark. In early spring the female Psyllas lay 

 their eggs on or near the buds and these eggs hatch into 

 little Psyllas that suck the sap from the stalks of the 

 developing leaves. These become full grown in early 

 summer and lay eggs for a second brood, which in turn 

 is followed by other summer broods, throughout the 

 season. Spraying as soon as the blossoms fall with 

 dilute kerosene emulsion or a solution of whale-oil soap 

 is an effective remedy. 



Vertebrate Enemies 

 Meadow-mice seem particularly fond of the bark of 

 young pear trees. Under the protection of the snow 

 they frequently strip off practically all the bark for a 

 foot or two above the ground. The best way to prevent 

 such damage is to enclose the trunk in wire netting of a 

 mesh small enough to prevent the gnawing or else to 

 paint the trunk with white lead and raw linseed oil. 

 Injury by rabbits will also be prevented by either method, 

 if the protection extends far enough up the trunk. 



