NEW YORK STATE MUSEUM 



drop and suspend themselves with a silken thread, a position very annoying 

 to persons obliged to pass under, an infested tree, and as many shade 

 trees were attacked recently, this feature was painfully apparent. If the 

 shock is sudden, the caterpillars drop without spinning a web. As they 

 become about half grown, they frequently form good sized clusters on the 

 larger limbs and trunk of an infested tree. If the creatures are very 

 abundant, they may strip the tree before full growth is attained and then 

 be forced by hunger to invade neighboring orchards. The maple trees 

 represented on plate 32 show well the work of this insect. Ordinarily, as 

 the caterpillars approach maturity, many of them forsake the tree and crawl 

 in all directions. Thus in obedience to a natural impulse, they may crawl in 

 numbers over walks, piazzas and swarm on sides of houses. This wan- 

 dering, prior to pupation, occurs about June i, the transformation to the 

 pupa taking place from about the middle to the last of June. The insect 

 remains in the pupa state about two weeks, the moths appearing the latter 

 part of June and during July, mostly in the latter month. The eggs are 

 deposited during July, a large proportion of them being laid on the lower 

 twigs, but many are found over 20 feet from the ground and numbers even 

 in the tops of tall trees. 



Food plants. Like the comnion tent caterpillar, this insect can sub- 

 sist on a large variety of plants. Its favorite species of oak in the Southern 

 States, as given by the late Dr Riley, are those belonging to the same 

 group as the black oak. In New York and adjoining states this insect is 

 reported more frequently as defoliating the sugar maple than any other 

 tree. This may be owing to the fact that large sugar orchards afford the 

 most favorable conditions for the caterpillars in the north, and as the 

 maples are of greater value than forest trees, complaints of attack are more 

 frequent. The caterpillars have been reported by various writers as feed- 

 ing on the following trees and shrubs: linden, maples, locust, peach, plum, 

 cherry, rose, strawberry, apple, sweet gum (Liquidambar st)-ra- 

 ciflua), dogwood, " black gum," sour gum (Nyssa sylvatica), ash, 

 elm, black walnut, hickory, walnut, oak, black oak, post oak, white birch, 

 gray birch, willow and poplar. 



