THE CARE OF SHADE TREES. 



99 



masses of egg^s, which remain over winter 

 on the trunks and larger branches, and even 

 on buildings and fences near by, may be 

 scraped off and destroyed during the winter. 

 If a few survive this treatment to show them- 

 selves as larvae, spraying with Paris green 

 will kill most of them. The bands of tar 

 brushed on the trunks three or four feet from 

 the ground will prevent the wingless female 

 from ascending the trees to lay her eggs. 



Fig. 1759. Fall Web-Worm— a, cater- 

 pillar ; b, pupa ; c, moth. 



The Fall Web-worm {Hyphanti-id cm tea) is 

 another serious pest of shade trees. (Fig. 

 1759.) The moth is either pure white, or white 

 spotted with black, and is a very pretty 

 creature. It lays a cluster of 300 or 400 

 eggs on the leaves. The caterpillars feed in 

 colonies, and each colony spins a web where- 

 ever it feeds. When full grown, the cater- 

 pillars leave the web and crawl down the 

 trunk to the ground to spin their cocoons, 

 within which they pass the winter as pupae. 

 Several methods may be adopted to rid the 

 trees of the pest. The collection of the co- 

 coons, and the spraying with Paris green are 

 both effective, but perhaps, the most effect- 

 ive mode of treatment is to burn the webs 

 and the contained caterpillars. A long pole, 

 to the end oS. which a swab saturated with 

 coal-oil is fastened, makes a good torch for 

 burning the webs. 



The Bag-worm {Thyridopteryx ephetnera- 

 formis), although rare with us on shade trees, 

 is a pest in some cities to the south of us. 

 During the winter silken bags, to which bits 



of leaves and sticks are attached, may fre- 

 quently be found on the twigs of conifers 

 and other trees. These bags contain eggs 

 which hatch in the spring, the little cater- 

 pillars emerging from the bags and feeding 

 upon the leaves. They become mature, or 

 full grown in late summer, when the bags, 

 which they have constructed and carried 

 about with them, are fastened securely to 

 branches, or sometimes to fences near bv. 

 Within the bags the caterpillars change to 

 pupae. The male moths soon emerge, but 

 the female moths being wingless and passive, 

 never leave the bags, where thev lav large 

 masses of eggs. 



The surest remedy for the bag-worm is to 

 pick the bags during the winter and destroy 

 them. If the bags are destroyed no cater- 

 pillars can make their appearance unless they 

 come from some outside source. 



3. The chief Sap-Suckers are the Wooly 

 Maple Bark-Louse, or the Cottouv Maple 

 Scale, the Spruce Gall Louse, and several 

 kinds of armored Scale-insects. These all 

 have mouth-parts adapted for sucking the 

 juices of the plants they infest. 



The Cotto7iy Maple Scale (Pulvniaria in- 

 nmnerabilis) is very frequently injurious to 

 maples. (Fig. 1760.) These scales attract 

 attention in the spring by the large cottony 

 masses which envelope them. Within the 

 cottony mass are the eggs, from which in a 

 short time the young lice hatch, and spread 

 over the branches and twigs. They soon 

 settle on suitable spots, and begin feeding by 

 sucking the sap. Full growth is reached 

 about the beginning of September, when 

 winged males appear. The females, how- 



FiG. 1760. Cottony Maple Scalk— Showing 

 the insect lying on a cottony mass which 

 contains eggs. 



