ORCHARD INSECTS OF THE PACIFIC NORTHWEST 



41 



with a dark band along the back. It constructs a flimsy, brown cocoon 

 in trash on the ground; from this cocoon the moth emerges late in the 

 spring. The moth is usually pure white or spotted with dark-colored 

 dots. It lays pale-green eggs in a flat mass on a leaf, covering them 

 with white hairs from its body. The 

 eggs hatch in about 10 days. There 

 is only one brood annually in the 

 Pacific Northwest. The insect occurs 

 in the area west of the Cascade 

 Mountains and in Idaho. 



Apple and pear trees that are regu- 

 larly sprayed with arsenicals are not 

 harmed by the fall webworm, as the 

 caterpillars appear after some of 

 these sprays have been applied, and 

 the small worms succumb readily to 

 the poison on the foliage. On shade 

 trees or fruit trees not ordinarily 

 sprayed, a special application of lead 

 arsenate, 2 pounds to 100 gallons, is Figure 48. 

 effective if applied while the cater- 

 pillars are still small. The cater- 

 pillars may also be destroyed in their webs by burning, as suggested 

 for the tent caterpillar. This may be done during the day. 



Tussock Moths 



The rusty tussock moth (Notolophus antiqua (L.)) and the western 

 tussock moth (Hemerocampa vetusta (Bdv.)) are leaf -feeding insects 

 occurring chiefly west of the Cascade Mountains. The first-men- 

 tioned species passes the winter in the egg stage in dry leaves or on 

 tree trunks or twigs. The caterpillars appear in April and subsist 

 mainly on the foliage, but occasionally damage the fruit, and may 

 be found on a great variety of trees and shrubs. They feed for a 

 month or more, and when full grown are about 1 inch long, hairy, 

 blackish or bluish, with several thick tufts of hairs along the back. 

 The male moth has rusty-brown wings, but the female is practically 

 wingless and deposits her eggs in a mass on the cocoon from which 

 she emerged. A second brood of caterpillars appears late in July and 

 produces moths in September; these in turn deposit the overwintering 

 eggs. The western tussock moth has similar habits, except that there 

 is but a single brood each year, the eggs laid in July hatching the 

 following spring. Special control is seldom necessary, since sprays 

 applied for other leaf -feeding caterpillars keep these insects in check. 

 Many of the egg masses may be found and destroyed when the 

 trees are pruned. 



Apple Lacebug 



The apple lacebug (Corythucha drakei Gibs.) is a pest of the apple 

 in Washington and Oregon. The young and adults feed on the lower 

 surface of the leaves, usually in groups. They dot the leaves with 

 black spots of excrement, and as the insects suck out the juices the 

 leaves become yeUowed and eventually drop. The adult insect is 



