. Insects injurious to fruits. Illustrated with four hundred and forty wood-cuts. Insect pests. No. 156.—The Grape-vine Saw-fly. Selandria vitis Harris. This is a small four-winged fly (Fig. 295), with a shining black body, except the upper side of the thorax, which is red ; the wings are semi-transparent, and have dark-brown veins, the front pair being clouded, or of a smoky color. The fore legs and under side of the other legs are pale yellow or whitish. The body of the female measures about three- tenths of an inch in length, that of the male somewhat less. The insect is double-brooded, the
. Insects injurious to fruits. Illustrated with four hundred and forty wood-cuts. Insect pests. No. 156.—The Grape-vine Saw-fly. Selandria vitis Harris. This is a small four-winged fly (Fig. 295), with a shining black body, except the upper side of the thorax, which is red ; the wings are semi-transparent, and have dark-brown veins, the front pair being clouded, or of a smoky color. The fore legs and under side of the other legs are pale yellow or whitish. The body of the female measures about three- tenths of an inch in length, that of the male somewhat less. The insect is double-brooded, the first brood of flies appearing in the spring, the second late in July or early in August. The eggs are laid on the under side of the terminal leaves of the vine in small clusters, and the larvae, when hatched, feed in company, side by side, from about half a dozen to fifteen or twenty in a group, preserving their ranks with much regularity, as shown in Fig. 296. They begin at one edge of the leaf and eat the whole of the leaf—including the ribs—to the stalk, and proceed from leaf to leaf down the branch, devouring as they go, until they are full grown. When mature, they measure about five-eighths of an inch in length, are somewhat slender and tapering behind, and thickened before the middle. They are of a pale-yellow color, darker or greenish on the back, with two transverse rows of minute black points across each ring, the head and tip of the last segment being black; the under side is yellowish. After the last moult the larvae become entirely yellow, when they leave the vines, descend to the ground, and burrow under its surface. There they form oval cells in the earth, which they line with silk, and within these enclosures change to chrysalids, from which the perfect flies escape in about a fortnight. The second brood pass the winter in the chrysalis state. In Fig. 296 one of the oval Fm. Please note that these images are extracted from scanned page images that m
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Keywords: ., bookcentury1800, bookdecade1880, bookpublisherphila, bookyear1883
