HICKORY. XEUNK — TIGER CERAMBYX. ITS BURROW. 



147 



liad for many years advanced but little in size, and some of their 

 limbs were annually perishing and falling to the ground. And 

 in every instance where a tree was infested at all, it was badly 

 infested ; and the wood of the hickory which is so much esteemed, 

 and for particular uses is so valuable in consequence of its tough- 

 ness and elasticity, when once attacked by these borers and the 

 ants which succeed them, becomes so extensively, perforated and 

 mined as to be worthless for anything except fuel. 



The burrow of this worm i« excavated in the solid heart- wood 

 of our American hickories and walnuts, and is almost two feet ia 

 length. It runs longitudinally upwards, in- 

 creasing in diameter as the worm has increased 

 in size. The annexed cut gives a view of por- 

 tions of two of these burrows much reduced ia 

 size. The hole which the worm bores is some- 

 what flattish, or more wide than high, and in its 

 largest part it is nearly half an inch in width, 

 and considerably over a quarter of an inch in 

 depth. At its. upper extremity it turns obliquely 

 outwards through the sap-wood to the bark. 

 All the lower part of this gallery is iilled with 

 a fine powder, of a tan color, the castings of the worm; and some 

 two or three inches below its upper end, in place of these fine 

 castings, it is stuffed for a distance of an inch and a half, or more, 

 with a coarser material, namely, short fibres of wood, which are 

 bent and packed together commonly in a perfectly regular man- 

 ner. Above these is another layer of the finer castings, the upper 

 end only of the burrow being vacant. And I presume this borer, 

 like that of the apple tree, having completed its burrow and 

 opened it out to the bark, retires backwards a short distance and 

 stuffs the upper end of the cavity with its castings, having the 

 castings above it and the cushion of coarser woody fibres imme- 

 diately below it during its inactive larva and its pupa state — the 

 coarser fibres being placed there as a bed for the pupa to lie 

 upon — by their elasticity yielding to any elongation or other mo- 

 don of the slumbering insect, which the fine castings wouM 

 become too compact and solid, by their settling together, to per- 



