ENTOMOLOGY 307 



tacked and killed, then the infestation spreads into the other branches 

 and trunk. 



The tiny borer, hatching from an egg laid by the adult or bee- 

 tle on the bark, begins a narrow mine or burrow through the bark. 

 The burrow is extended in a tortuous or zigzag direction along the 

 branch, getting wider as the borer grows, and running mostly in 

 the sap-wood just beneath the bark, but sometimes going for a short 

 distance deeper into the wood, even to the center of the branch. 



There is no known way of preventing this bronze birch borer 

 from attacking white birches, and the only practicable and effective 

 method yet found for checking its ravages is to promptly cut and 

 burn the infested trees in autumn, in winter, or before May 1st. 

 There is no possibility of saving a tree when the top branches are 

 dead. Cut and burn such trees at once and thus prevent the spread 

 of the insect. (Bui. 234, Cornell Agr. Exp. Sta.) 



Wood Leopard Moth or Imported Elm Borer. This is an in- 

 sect that was accidentally imported over fifteen years ago from some 

 European country and made its start at Hoboken. Practically all 

 kinds of shade trees and many shrubs are attacked by the larva, 

 which is both a borer and a true caterpillar. The parent moth is 

 quite large, the males measuring an inch and a half and the females 

 two and a half inches between the tips of the fore wings. These 

 wings are white with numerous black spots and the body is black 

 spotted in its anterior portion. The head in the male has a pair of 

 densely feathered antennae or feelers, and the abdomen extends back 

 an inch and a half or more. Altogether the creature is readily 

 recognizable and is found, during the season in which it flies, around 

 electric lights in the cities where it occurs. The period of flight be- 

 gins during the last days of May and extends through June, July 

 and into August. It is during the latter days of June and in early 

 July that the insects are most abundant and the males are always 

 most active around the lights. The females are heavily built and, 

 when the eggs are developing, rarely move far from the trees out of 

 which they were born and upon which they afterward oviposit. 

 The eggs are small, salmon-pink in color, and may be laid singly or 

 in masses, a single adult depositing between five hundred and one 

 thousand or even more. They are usually placed in a bark crevice 

 or other sheltered situation and generally on one of the smaller 

 branches. The little caterpillar, when it hatches, makes its way to 

 the crotch of a small branch, or to one of the nodes or buds and at 

 once bores into the wood tissue. It works downward, toward the 

 base, and grows very rapidly. When it is tired of its quarters, or 

 when they become too narrow, the insect works out; sometimes di- 

 rectly, sometimes by cutting all around on the inside so that the 

 twigs break off. Then it makes its way further down, selects a 

 larger branch and again begins feeding. Each individual seems to 

 be a law unto itself as to the manner in which it feeds; it may bore 

 a straight channel through the center of the branch, it may eat out 

 a large cavity on one side, or it may deliberately work around and 

 kill it. By the end of the first season the larva is half-grown and has 



