NURSERY AND ORCHARD INSECT PESTS 



25 



Pear Slug (Eriocampoides limacina). This pest attacks the foliage of 

 pear and cherry often very badly. It is a small greenish, slimy worm similar 

 to the rose slug and related species. Often a dozen may feed on one leaf, con- 

 suming the surface layer, which causes the leaf to dry up. The pest develops 

 two broods a year, the adults of the first appearing in June while the adults 

 of the second appear in August. The first brood is most destructive. 



The pest attacks the foliage of trees both in the nursery and in the orchard. 

 As a rule cherry is attacked more severely than pear. 



FIG. 28. Pear slug: a, Adult female sawfly; b, larva en- 

 larged; c, back view of same; d, injured leaves with 

 larvae, natural size. (After Marlatt) 



CONTROL. Where the regular summer sprays are applied to bearing trees 

 the pest will be controlled. On nursery stock the pest can be controlled by 

 dusting or spraying with an arsenical. 



INSECT PESTS OF THE PEACH 



The peach in the nursery and orchard is not subject to as many pests as is 

 the apple, however, there are a number of important peach pests. Of these 

 the peach-tree borer, the San Jose scale, the plum curculio, the tarnished plant- 

 bug, the peach twig-borer, the shot-hole borer, and black peach aphis are usually 

 the most important. 



Peach-tree Borer (Sanninoidea exitiosa). This is a caterpillar borer 

 which, while especially important in the orchard, may at times attack older peach 

 stock in the nursery. Its presence is usually readily recognized by the appear- 

 ance of peach gum about the base of the tree. . The borer varies from a very 

 tiny whitish caterpillar to one an inch long and of a yellowish-white color. It 

 works between the bark and the wood from a few inches above the ground 

 usually to a few inches below ground. The adult moth resembles a wasp in 

 appearance and action. The male has transparent wings and the body steel- 

 t>lue in color with yellow on the tip while the female is larger, wings more 



