ENGLISH: ILLINOIS TREES: THEIR INSECT ENEMIES 75 



of the wing covers. They are strong fliers. They are very fond of 

 eating ripening apples, corn silk, grape foliage, and soybeans. 

 The female deposits eggs in the soil to produce grubs that feed 

 on the roots of grasses. The grubs spend the winter in the soil, 

 resume feeding in the spring, complete growth, and pupate. The 

 adults emerge from the pupae in late June or July and feed for 

 several months. This insect produces one generation each year. 



Gypsy Moth, Porthetria dispar (L.), fig. 53. — Of all the leaf- 

 feeding pests that attack shade and woodland trees, the cater- 

 pillar of the gypsy moth is the most destructive. It feeds on 

 nearly all deciduous trees, and, except in the early stages of its 

 development, on many evergreens. Most of the area infested by 

 this insect lies east of the Hudson River. An infestation in Mich- 

 igan was discovered a few years ago, but there is some hope of 

 eradicating it. 



The female moth deposits eggs in hair-coated clusters on 

 tree trunks, buildings, and other objects. The full-grown cater- 

 pillar, 2 to 2Y2 inches long, is covered with tufts of long brown 

 hair and has five pairs of blue tubercles along the back followed 

 by six pairs of red tubercles. 



The insect overwinters in the egg stage. The eggs hatch as 

 the leaves of trees unfold in spring. The caterpillars feed for 

 about 2 months, during which time they may strip trees of their 

 foliage. Pupation occurs in cocoons fastened to tree trunks. The 

 adults emerge in late July, and the female deposits the eggs that 

 carry the species through the winter. The female is buff in color, 

 the male brown. 



Brown-Tail Moth, Nygmia phaeorrhoea (Donov.). — The cat- 

 erpillar of this species feeds on the foliage of a wide variety of 

 trees, including oak, elm, maple, willow, apple, pear, and plum. 

 Like the gypsy moth, the brown-tail moth is confined mainly to 

 the New England states. 



The male as well as the female is white, except on the tip of 

 the abdomen, which is covered with brown hairs. The caterpillar 

 is reddish brown and has a broken yellow stripe along each side 

 of its body. The body is covered with stiff barbed hairs, which 

 may cause a very irritating rash on human beings. 



The partly grown caterpillar, which overwinters in a nest of 

 webbed leaves, feeds for a while in the spring before pupating. 

 The adults emerge in July, and the female deposits masses of 

 brown eggs on the under sides of leaves. 



