60 OUR, SHADE TREES AND THEIR INSECT DEFOLIATORS. 



chrysalis skin or puparium. She then tails to the ground and perishes. 

 The eggs remain in the bag all winter and hatch in spring into young 

 ■worms, which scatter and at once make new bags, which increase with 

 their growth and protect them from the attacks of birds. 



The male moth is a small, black, hairy-bodied creature, with ample 

 transparent wings, and escapes from the chrysalis after it is partially 

 worked out of the hind end of the bag. This worm is a very general 

 feeder, but is, on the whole, more injurious to evergreens than to de- 

 ciduous trees. 



This species has several insect parasites. 



3. The White-marked Tussock moth has a very beautiful hairy larva 

 or caterpillar marked with black and yellow and red. The female co- 

 coons are to be found during the winter on the trees and upon neighbor- 

 ing fences and tree-boxes, and each cocoon is plastered with a number 

 of eggs, protected by a white, frothy, glutinous covering. The eggs 

 hatch iu spring and the young worms feed upon the fresh leaves. The 

 males spin their cocoons after three molts and the females after four. 

 The moths issue in July, pair and lay eggs for a second brood of worms, 

 which in turn transform and bring forth moths in October, the eggs 

 from which hibernate. The male moth is active, with ample wings, 

 which are brown, with a conspicuous white spot, while the female is 

 pale and wingless, and only crawls out of her cocoon to lay her eggs 

 thereon and die. This species is never found on evergreens, and is 

 chiefly injurious to elms and maples, and prefers large and old trees 

 to young ones, because of the greater shelter which they offer for its co- 

 coons. In Washington it is yet chiefly confined to our parks, and it 

 has not begun to be as injurious as in cities like Philadelphia and Bal- 

 timore, where the trees are older and larger. Two probable* egg-para- 

 sites and seven parasites of larva and pupa are known to me. 



4. The Fall Web-worm passes the winter in the pupa state. The 

 cocoons are found during the winter principally at the surface of the 

 ground, mixed with dirt and rubbish, or in cracks and crevices of tree- 

 boxes, in fences, and under door-steps and basement walls. The first 

 moths issue from these cocoons in May, and lay their eggs in flat batches 

 on the under side of the leaves. The young worms feed preferably in 

 company, w r ebbing first one and then several leaves together, and 

 gradually extending their sphere of action until a large part; of the tree 

 becomes involved. The worms become full grown in July and spin 

 cocoons, from which a second generation of moths issue early in August 

 and lay eggs, from which the worms hatch; so they are once more in 

 force by the latter part of August. This is the species which did the 

 damage last year. The parent moth is white, with a varying number 

 of spots; is winged in both sexes; and the female prefers to oviposit on 

 Box Elder {JXegundo aceroides), the Poplars, Cottonwoods, Ashes, and 

 Willows. The worm feeds ; however, on many other trees, but not upon 

 Conifers. It has numerous enemies and parasites. 



