THE OAK-PRUNER. 85 



not more than thre 3-fourth8 of the wood will be severed. The annexed figures* repre- 

 sent the several ends of limbs of different sizes, the coarsely dotted parts of the two 

 first indicating the ragged broken ends of the woody fibers, the remainder being the 

 smooth surface cut by the worms, and the large black dot representing the perfora- 

 tion leading up the limb to where the worm lies. The first of these figures was taken 

 from the limb already spoken of as ten feet in length, and here it will be noticed that 

 a portion of the stouter wood towards the center of the limb was preserved, as though 

 the worm had been aware that the weaker sappy fibers outside next to the bark could 

 not be relied upon for sustaining a limb of this size, as they are where the limb is 

 smaller. With such consummate skill and seemingly superterrestrial intelligence does 

 this philosophical little carpenter. vary his proceedings to meet the circumstances of 

 his situation in each particular case! But by tracing the next stage of his life w© 

 shall be able to see how it is that he probably performs these feats which appear so 

 much beyond his sphere. 



Having cut the limb asunder so far that he supposes it will break with the next 

 wind which arises, the worm withdraws himself into his burrow, and that he may 

 not be stunned and drop therefrom should the limb strike the earth with violence 

 when it falls, he closes the openiug behind him by inserting therein a wad formed of 

 elastic fibers of wood. He now feeds at his leisure upon the pith of the main limb, 

 hereby extending his burrow up this limb six or twelve inches or more, until he at- 

 tains his full growth — quietly awaiting the fall of the limb and his descent therein 

 to the ground. It is quite probable that he does not always sever the limb sufficiently, 

 in the first instance, for it to break and fall. Having cut it so much as he deems 

 prudent, he withdraws and commences feeding upon the pith of the limb above the 

 place where it is partially severed, until a high wind occurs. If the limb is not 

 hereby broken, as soon as the weather becomes calm he very probably returns and 

 gnaws oif an additional portion of the wood, repeating this act again and again, it 

 may be, until a wind comes which accomplishes the desired result. And this serves 

 to explain to us why it is that the worm severs the limbs at such an early period of 

 his life. For the formidable undertaking of cutting asunder such an extent of hard 

 woody substance, we should expect he would await till he was almost grown and had 

 attained his full strength and vigor. But by entering upon this task when he is but 

 half grown he has ample opportunity to watch the result, and to return and perfect 

 the work if he discovers his first essay fails to accomplish the end he has in view. 



Thus the first part of the life of this worm is passed in a small twig branching off 

 from the main limb. This is so slender and delicate that ou being mined as it is by 

 the worm and all its green outer end consumed, it dies and becomes so decayed and 

 brittle that it is usually broken off when the limb falls, whereby it has. escaped the 

 notice of writers hitherto. The remainder of his larva life is passed in the main 

 limb, first cutting off this limb sufficiently for it to break with the force of the winds, 

 and then excavating a burrow upwards in the center of the limb, both before and 

 after it has fallen to the ground, feeding hereon until he has grown to his full size. 



It is most frequently the limbs of the red and the black oak that I have met with 

 severed by the oak pruner, though it is not rare to find those of the scarlet oak (Q. 

 coccinea) and of the white oak lopped off in the same manner. Limbs of the beech 

 and chestnut not unfrequeutly and those of the birch, the apple, and probably of 

 other trees, are sometimes similarly severed. Mr. P. Weter, of Tirade, Walworth 

 County, Wis., informs me that the peach in his vicinity suffers in a similar man- 

 ner, and to such an extent some years that the severed limbs, varying from a few 

 inches to two feet in length, are seen lying under almost every tree. We have in our 

 country several species of beetles very closely related to the oak pruner, but no at- 

 tempts have yet been made to ascertain their mode of life. It is very probable that 

 they all have this same habit of cutting off the limbs of trees, one perhaps preferring 

 the wood of one kind of tree, another, another. This is the more probable, sine© 



* The figures have not been reproduced. — A. S. P. 



