INSECTS AFFECTING PARK AND WOODLAND TREES "J 



ance of the insect in new localities in the State. Searching for indications 

 of the borer's presence along- the Hudson River, specially in cities and vil- 

 lages, may result in its detection in several new localities. 



Life history and habits. Moths may be taken from early June till the 

 latter part of September. European authorities state that the female places 

 her eggs in crevices of the bark in branches as well as the trunk. Since the 

 young caterpillars frequently enter the twigs at the base of a bud [pi. 4, 

 fig. I !(?], it seems quite probable that many of the oval, salmon colored eggs 

 may be thrust between the stem and bud or under a bud scale. Several 

 observers have noted the deposition of about 300 eggs by the female in con- 

 tinement and some writers estimate that she may deposit as many as 1000 

 eggs. When a young caterpillar enters a twig, it usually tunnels along the 

 pith, eating away the wood here and there almost to the bark. The expelled 

 frass at the base of the bud indicates the point of entry. As the caterpillar 

 works along the twig, it occasionally makes an opening for the e.xpulsion of 

 its frass [see pi. 4, fig. 8]. These orifices, after they have served their pur- 

 pose, are closed by a web of silk, as represented at figure 7 on plate 4. 

 This singular habit of closing these holes when no longer needed, probably 

 affords considerable protection from insect parasites and it would also tend 

 to prevent birds from finding the caterpillars so readily. The smaller twigs 

 frequently wilt and break as a result of the work of this borer. The latter 

 part of September caterpillars 3,8 inch long were found, having probably 

 hatched from eggs laid the latter part of the summer, and the larger borers, 

 about one inch long, from eggs deposited earlier in the season. These 

 creatures have a habit of leaving their burrows, wandering to another part 

 of the limb or even to other branches, and commencing operations anew. 

 As they increase in size, larger limbs are attacked and nearly full grown 

 caterpillars are frequently found in the trunk. In the larger limbs and in 

 the trunk, these borers make very bad work. Sometimes a caterpillar will 

 nearly girdle a tree with a burrow just under the bark. Frequently several 

 burrows run side by side, as represented in figure 10, plate 4. Many of the 

 caterpillars will keep gnawing away just under the bark till an irregular 



