. Biennial report of the Oregon State Board of Horticulture ... Horticulture -- Oregon; Fruit-culture -- Oregon; Gardening -- Oregon. 398 REPORT OF STATE BOARD OF Fig. 3 — Pear slug: a, last moulted larval skin; b, larva after castinglastskin —somewliat enlarged (orig- inal). leaf that it can be readily watched and its gradual- increase absorption from the leaf and the development of the young- larva can be easily studied with a hand lens. The larva emerges on the upper surface of the leaf through a very regular semicircular cut which it makes near the center of the cell. At fir
. Biennial report of the Oregon State Board of Horticulture ... Horticulture -- Oregon; Fruit-culture -- Oregon; Gardening -- Oregon. 398 REPORT OF STATE BOARD OF Fig. 3 — Pear slug: a, last moulted larval skin; b, larva after castinglastskin —somewliat enlarged (orig- inal). leaf that it can be readily watched and its gradual- increase absorption from the leaf and the development of the young- larva can be easily studied with a hand lens. The larva emerges on the upper surface of the leaf through a very regular semicircular cut which it makes near the center of the cell. At first it is clear or free from slime and in color nearly white, except the yellowish brown head: but almost im- mediately the slimy or gluey olive-colored liquid begins to exude over its entire body, giving it the appearance of a minute slug, or soft snail, from which it gets its name. Its head is dark brown, appearing black under the slime, and the body also becomes almost equally dark. The anterior seg- ments are much swollen, covering up and conceal- ing the head and thoracic legs. In common with other saw-fly larvae it has a great number of false legs or prolegs on the abdominal segments; in this species there are fourteen such prolegs, the terminal pair being wanting, and the tapering tip of the body is usually slightly elevated. As soon as the larva emerges from the egg it begins feeding on the upper surface of the leaf, eating out small holes or patches about the size of a pin head or smaller, but never eating entirely through the leaf. The larvse feed almost invariably on the upper side of the leaves and the minute eaten spots which they make at the start rapidly increase in size until much of it, but not the entire surface of the leaf, is denuded, leaving merely a network of veins, or a leaf skeleton, held together by a nearly intact lower epider- mis. Leaves thus eaten turn brown, die, and fall to the ground, the tree being frequently defoliated, except for the effor
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