158 • TREES IN WINTER 



Elder and Maple. The eggs are deposited either in late fall or 

 early spring, and hatch about Ma}^ first. Usually the young cat- 

 erpillars completely devour the tissue of the leaves, leaving noth- 

 ing but the veins. About the first of June they become full grown 

 and are almost an inch in length. They let themselves down by 

 means of a silken thread and go into the ground where they remain 

 in the pupal state until fall. The adults of the fall species 

 emerge in Xovember and the wingless females may be seen crawling 

 up the trunks of trees to deposit their eggs on the branches. The 

 adults of the spring species emerge in March or April. 



Since the females cannot fly, they must crawl up the trees to lay 

 their eggs, and this suggests the method of control. The pest may 

 be kept completely under control by banding the trees. (See fig. 

 75). Spraying with arsenate of lead (ten pounds to 100 

 gallons of Avater) will destroy all insects that hatch from the eggs 

 already on the trees. 



Elm-Leaf Beetle — This is another imported insect and is one 

 of the worst pests of the Elms. Fortunately its ravages are restrict- 

 ed to the Elms. Tiie adult beetles are a fourth of an inch in length 

 and are yellowish, grayish, or dull olive-green in color with an in- 

 distinct dark line along each side of their back. They usually 

 spend the winter in the attics of houses or other sheltered places. 

 They appear early in May and commence feeding on the newly- 

 formed leaves, making characteristic round holes. During the 

 latter part of May or early in June the beetles deposit the familiar 

 orange-colored eggs on the under side of the leaves. These hatch 

 in about a week and the young grubs commence feeding on the un- 

 der side of the leaf. The grubs mature in about three weeks and 

 descend to the base of the tree, where they change to pupae. A sec- 

 ond brood sometimes occurs. 



Spraying the newly-formed foliage in May with arsenate of lead 

 will usually be sufficient to control the pest, but occasionally a sec- 

 ond application as soon as the grubs appear, will be necessary. 

 The pupae around the base of the tree may be killed by spraying 

 with strong kerosene emulsion. 



Gypsy Moth — This destructive insect was imported accidentally 

 about forty years ago. Its larva feeds on almost any kind of veg- 

 egation, including all kinds of shade trees and ornamental shrubs. 

 The eggs are laid usually on the trunks and branches of 



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