REPORT OF THE COMMISSIONERS OF FISHERIES, GAME AND FORESTS. 383 



base of the bud indicates the point of entry. As the caterpillar works along the twig, 

 it occasionally makes an opening for the expulsion of its frass, see plate 2, figure 8. 

 After they have served their purpose, these orifices are closed by a web of silk, as 

 represented at figure 7 on plate 2. 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 three eighths of an 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 2. Many of the caterpillars will 

 keep gnawing away just under the bark till an irregular chamber the size of a man's 

 hand has been made. The bark covering these large wounds soon dies, breaks away 

 and the following season there is an ugly scar, as represented at figure 9, on plate 2. 

 In a short time small trees harboring several of these creatures are quickly girdled. 

 Two years are required to complete the life cycle, according to most authorities. The 

 first winter is passed by the small caterpillar, usually less than an inch long, in its 

 burrow. The second winter it is nearly full grown (Plate 2, figure 4). The transfor- 

 mation to the quiescent pupa (Plate 2, figure 5) takes place in the burrow, the bark 

 having previously been eaten nearly through by the caterpillar. Before the adult 

 appears, the pupa works itself partly out of the burrow (Plate. 2, figure 6) and the 

 moth emerges, leaving the empty pupal case as represented at figure 1, plate 2. 



This pernicious borer has been recorded as attacking eighty-three species of trees 

 and shrubs. According to the observations of Dr. E. B. Southwick, Entomologist to 

 the Department of Public Parks of New York, the elms and maples are most subject to 

 attack, the horsechestnut, Ohio buckeye (sEsculus glabra), beeches, birches, dogwood, 

 hickories, oaks, and walnuts suffering in the order named. Almost every species of 

 tree and shrub in Central Park, except evergreens, was injured to some extent. 



Remedies. Something can be accomplished by the destruction of the rather 

 sluggish females before eggs are deposited. This is of most value where there are 

 only a few small trees. In localities where this insect occurs, trees should be examined 

 three or four times a year. The wilting of smaller twigs and the strings of expelled 

 frass indicate the presence of this borer. Smaller infested branches can be cut off and 



