508 ECONOMIC ZOOLOGY AND ENTOMOLOGY 



she is provided with well developed wings. The female has the 

 wings whitish, marked with small black spots and wavy lines. 

 She lays her eggs on the trees, near-by fences or hedges or other 

 convenient objects. The egg masses, which consist of 400 or 500 

 eggs covered over with yellowish hairs from the insect's body, 

 remain over winter in these places. The young caterpillars, 

 which issue early in May, at once begin feeding on any available 

 foliage. They are covered with long hairs, and as they swing 

 from the branches by fine silken threads they may be carried 

 by winds for considerable distances, or they may drop on 

 passing vehicles and be transported for some miles before they 

 drop off. Thus new localities, not too far away, are easily 



FIG. 239. Gipsy-moth, Porthetria dispar, larva. (About 1/4 larger than 



natural size.) 



infected. The full-grown dark-brown larvas attain a length of 

 about three inches, and attack practically all kinds of wild and 

 cultivated trees and shrubs. A deciduous tree will often live 

 even after three or four defoliations, but the coniferous trees 

 die after one complete stripping. 



In the orchard this pest may be fairly well controlled by 

 painting the egg masses with creosote sometime during the 

 winter, or by spraying the leaves with arsenate of lead as soon 

 as the larvae appear in the spring. In the woodlot control is 

 much more difficult, and usually even impossible, although the 

 same measures as recommended for the orchard may some- 

 times be practicable. As the very young larvae do not feed on 

 conifers these trees may be protected by clearing out all brush 

 and deciduous trees. In its native home this insect is not such 

 a serious pest because it is controlled by its natural enemies. 



