Insects and insecticidesA practical manual concerning noxious insects and the methods of preventing their injuries . and by various species of insect parasites. Remedies.—These defoliators may be destroyedby spraying their food plants with Paris green orLondon purple, or the larvae may be crushed whengathered into heaps on the trunk at moulting time. The Woolly Maple Bark-louse. Pulvinaria presence of this insect is manifested in thespring and early summer by the occurrence uponthe twigs of maple trees, especially on the under side,9 144 INSECTS AFFECTING SHADE TREES. ?of a b
Insects and insecticidesA practical manual concerning noxious insects and the methods of preventing their injuries . and by various species of insect parasites. Remedies.—These defoliators may be destroyedby spraying their food plants with Paris green orLondon purple, or the larvae may be crushed whengathered into heaps on the trunk at moulting time. The Woolly Maple Bark-louse. Pulvinaria presence of this insect is manifested in thespring and early summer by the occurrence uponthe twigs of maple trees, especially on the under side,9 144 INSECTS AFFECTING SHADE TREES. ?of a brown, circular, leathery scale, about one-quarterof an inch in diameter, beneath which is a peculiar,fluffy, cottony mass (Fig. 72, a). In the spring theremay be found in each of these masses, great numbers{from 700 to 1,000) of small, white, spherical in summer these eggs hatch into young lice,which scatter over the trees, wandering about on thetwigs and leaves for a few days, and, finally, fixingthemselves upon the lower leaf surface, insert theirtiny beaks and suck out the sap. They remain in. Fig. 72. Maple Bark-louse: a, cottony scales on twigs; b, back view of scale, magnified; c, ventral view of scale, more magnified. this position several weeks, when a few of them be-•come fully developed winged males. These matewith the remainder, which are females, and soon die. INJURING THE BRANCHES. 145 But the females remain upon the leaves until nearlytime for them to fall in autumn, when they desertthem and migrate to the twigs, attaching themselvesby inserting their beaks into the bark. Here theyremain until the following season, the eggs grad-ually developing and being deposited during insects sometimes do great damage to mapletrees. They excrete or secrete a peculiar liquidwhich falls upon the leaves, and the ground beneaththe trees, which is sometimes called honey are a large number of parasitic and predace-ous insects that prey upon this
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