PEAR INSECTS. The insects attacking the pear are identical in many instances with those which attack the apples, the apple-borers, the San Jose scale. the oyster-shell bark-louse. and the codling moth all being found to attack the pear. The pear-tree psylla (Psyila pyri) is con fined to the pear. and is common and rather de structive in the Northern United States, extend ing westward as far as Aliehigan and southward to _Maryland and Virginia. It was probably im ported about Is:it?. from Europe, where it occurs abundantly, especially in Austria. The orange yellow eggs are laid by the adult insect upon the leaves of the trees, and the young insects, yellow in color. with crimson eyes, begin immediately to suck the sap from the leaf. It grows rather rapidly and has several generations (four or five) in the course of summer. It hibernates in the adult condition. It is preyed upon by a large number of natural enemies, principally by the golden-eyed lace-wing flies and the larvae of coceinellid beetles. The best remedy is a spring application of kerosene emulsion spray when the leaves are first unfolded. A combination of kerosene emulsion and Bordeaux mixture is n-e ommended where pear-blight occurs in the same orchard.
A bark-baring beetle, known as the pear-blight beetle (Xyleborus, pyri), frequently causes the death of many twigs of the pear tree by making small perforations at the bases of the buds. The adult beetle deposits its egg on the bud and the young larva bores down, following the course of the eye of the bud, toward the pith, around which it passes, consuming the tissues in its course, thus interfering with the circulation, and causing the twig to wither. The adult insect issues in June or July and deposits its eggs during August. The only remedy which has been suggested is to cut oil' the blighted limbs below the injured part and burn them before the beetle has escaped. Another borer, the sinuate
pear-borer (Agrilus sinualns), has been intro duced into the United States from Europe within recent years. This borer in the larval condition feeds between the bark and wood in pear trees, especially in the trunk and larger branches, making long zigzag galleries, finally girdling the tree and killing it. It lives two years in the larval condition.
Among the numerous insects which attack the leaves of the pear is the so-called 'pear slug,' which is the larva of a saw-fl' (Eriocompoidrs limacina). The adult is a small insect, smaller than the house-fly, and glossy black in color. It was probably introduced into the United States from Europe toward the close of the eighteenth century. The eggs are laid under the surface of the leaf, and the young larva' hatch and grow rapidly, covering themselves with a slimy seere tion. There are two generations each year, and the larva. when abundant skeletonize near ly all the leaves on large trees. The best remedy is to spray with an arsenical wash or with a soap solution, or hellebore may be used either as a dry powder or as a wet spray. Heavy rains will often destroy them, and a forcible water spray will wash them from the leaves.
Among caterpillars which feed upon the pear are the white-marked tussoek-moth (Orgyia leu costigma), the red-humped apple-tree caterpillar (No!Morita concinna), the fall webworm (Ily phantria curler:), the ceeropia moth (Attacus cceropia), the eye-spotted bud-moth (nactocera °cellulr), and others. The plum eureulio and the quince eurculio (qq.v.) injure pears, as well as plums and quinces, although not so exten sively. Consult: Saunders, Insects Injurious to Fruits (Philadelphia, 1889); Smith, Manual of Economic Entomology (Philadelphia, 1896).