Scientific American Supplement, No. 803, May 23, 1891 by Various
page 32 of 143 (22%)
page 32 of 143 (22%)
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stunt the growth and make weak, sickly plants; while the second brood
feeds only on the outside leaves. The caterpillars are very active, wriggling violently when disturbed, and falling by a white silken thread. Hot dry weather is favorable to them and enables them to multiply rapidly. Advantage has been taken of this fact, and spraying the plants thoroughly with water is strongly recommended. Prof. Riley states that the insects are very readily destroyed by pyrethrum. There are two species of spiders and a species of ichneumon fly that destroy them. THE GARTERED PLUME MOTH. _Oxyptilus periscelidactylus_ (Fitch.) The caterpillars of this species draw together the young grape leaves, Fig. 26, a, in the spring, with fine silken threads, and feed on the inside, thus doing much damage in proportion to their size. These caterpillars, Fig. 26, a, and e, a segment greatly enlarged, are full grown in about two weeks, when they are about one-fourth of an inch long, pale green with whitish hairs arising from a transverse row of warts on each segment. Early in June they transform to pupæ, Fig. 26, b, which are pale green at first and change to dark brown. The surface is rough and the head is cut off obliquely, while on the upper side near the middle are two sharp pointed horns, Fig. 26, c. They remain in this stage from a week |
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