PLANTING AND CARE OF TREES 163 



comes a serious pest, but on Elms is controlled readily at the same 

 time that trees are sprayed for the leaf-beetle. The eggs are laid 

 early in May and are in cylindrical clusters around the twigs. They 

 hatch in about two weeks and the caterpillars arrange themselves 

 in rows facing the edge of the leaf. They completely skeletonize 

 the leaf, leaving only the veins, and later in the season, only the 

 mid-rib. When the caterpillars reach maturity, about the first of 

 July, they are nearly two inches in length, black with white and red 

 dots, and covered with black branched spines. About this time 

 they enter the pupal state which lasts about two weeks, when the 

 adults appear. The butterflies soon commence depositing eggs 

 which, when hatched, form the second brood of caterpillars. 



It is seldom necessary to spray especially for this pest. If found 

 on young trees they may be jarred off or the affected twigs may be 

 cut off and the insects destroyed. 



The Tent CaterpiUar and Fall Weh-worm — It is a common 

 occurrence to find unsightly looking webs in trees. These are 

 caused by tent caterpillars or fall web-worms. The larvae feed 

 on the foliage, but their chief injury is in giving the tree an 

 unsightly appearance. A species closely related to the ordinary 

 tent caterpillar that is commonly found on Apple Trees, is called 

 the forest tent caterpillar. This insect does not build a tent, but 

 spins a silky Aveb along the branches and the caterpillars congre- 

 gate in clusters in much the same way as the other species. 



The best method of controlling these pests is to cut off and 

 burn the webs with the insects. Spraying with arsenate of lead 

 will kill the young caterpillars, but does not get rid of the unsightly 

 web. 



Tussock Moth — The handsome larvae of this insect is a common 

 shade tree pest in towns and cities. It feeds on the foliage of 

 almost all ornamental trees except the evergreens. The insect 

 passes the winter in the egg stage. The young caterpillars appear 

 in May and commence to feed on the under side of the leaves, 

 eating the green portion and leaving the framework. When they 

 become larger they eat holes through the leaf and when full 

 grown they eat the entire leaf except the mid-rib. 



The full grown larva is very striking in appearance, of yellow 

 color beneath, with gray strij)es along the sides, and a black stripe 

 between two yellow ones along the back. Along the sides are a 



