16 APPLE-TRUNK BORER — ITS BURROW. 



turns itself around to its former posture, with its head upwards, 

 becomes inactive, and lies dormant during the winter season, and 

 the following spring is transformed to a pupa. From this pupa 

 the perfect insect soon after hatches, and tearing away the saw- 

 dust like powder which has been packed in the upper end of its 

 burrow, it has only to break through the bark here, which it 

 easily does with its sharp, powerful jaws, to come ouffof the tree. 



It will thus be seen that the burrow of this worm consists of two 

 distinct parts — a round flat excavation in the sap-wood, imme- 

 diately under the bark, and a long round hole in the solid wood, 

 running upwards from the upper part of the flat cavity, first in- 

 wards towards the centre of the trunk, and then outwarc^s to the 

 bark. This upper portion of the burrow is variable in its length, 

 being sometimes no more than an inch and three quarters, and at 

 other times, as I am informed, a foot or more. The lower flat 

 portion, as already stated, is about the size of a dollar, but is fre- 

 quently much larger than this; and when the worm comes to 

 knots or other obstructions when excavating it, instead of making 

 it round it is cut out in an irregular form. But in all cases the 

 worm passes the first periods of its life in consuming the sap- 

 wood, its jaws probably being too weak as yet to enable it to work 

 in the harder wood of the interior of the tree, and it is by thus 

 mining in the sap-wood, and cutting oft" so many of its vessels, 

 that this worm does the chief injury to the tree, stinting it in its 

 growth, and causing the leaves to assume a yellowish, sickly hue. 

 And where four or five worms are at work in one young tree, as 

 is often the case, these flat cavities in the sap-wood are liable to 

 come in contact with each other, and thus completely girdle and 

 destroy the tree. 



Numerous variations in the form and direction of the burrows 

 of these borers may be met with. Some of the worms seem to be 

 very wild and erratic in their proceedings. It is sometimes the 

 case that as soon as it reaches the sap-wood it works directly up- 

 wards, under the bark, and then turns, it may be, obliquely 

 downwards before entering the heart-wood. A most singular de- 

 viation from the usual habit was related to me by Esquire Bald- 



