86 FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSION. 



there is coasiderable diversity in their operatioas, as shown by au examinatiou of the 

 fallen limbs. Thus the scarlet oak, instead of having a hole bored in the severed end 

 of itslimb^, cointnonly has half the wood eaten away on one side of the limb for the 

 length of an inch or more, with the cavity thus formed under the bark packed with 

 worm dust, and a cylindrical burrow from the upper eud of this cavity running up- 

 wards in the center of the limb, the same as in other cases. 



It further appears that the female, when ready to drop an egg, is not always able 

 to find a small twig with a green succulent end adapted to her wants. She then con- 

 signs her progeny to the bark of the main limb, and the young worm subsists on the 

 soft pulpy matter between the bark and the wood, excav^ating a shallow irregular 

 cavity which is packed with worm dust, till it has acquired sufficient strength to 

 gnaw the wood, when it cuts off the limb as in other cases. It may, however, be a 

 different species from the common oak pruner, which cradles its young thus beneath 

 the bark instead of iu a lateral twig. It is usually in the fallen limbs of the beech, 

 though sometimes in those of the oaks also, that I have met with these worm tracks 

 under the bark. 



The bark ofithe beoch, it will be recollected, is quite thin and very brittle, so that 

 it will illy serve to hold the limb in its place if the wood .underneath is cur off in the 

 usual manner. And accordingly a remarkable modification of this operation will be 

 noticed in the amputated limbs of this tree. The worm eats its way down the limb 

 beneath the bark until it has acquired sufficient strength to sever the woody fibers. 

 It then passes transversely around the limb beneath the bark, girdling it by cutting 

 off all the softer outer fibers and leaving the harder ones in the middle of the lirag 

 uncut, whereby the limb is sustained until the wind strikes it. How surprising that 

 these little creatures have such intelligence given them as enables them to vary their 

 operations to such an extent, according to the circumstances of their situation in each 

 particular case! I should be inclined to think the beech pruner a different species 

 from that of the oak, as it dwells beneath the bark instead of in a lateral twig, and 

 cuts off' the outer instead of the inner wood of the limb ; but the worm is identical 

 with that of the oak in its external appearance, and one of these worms which I 

 placed in a cage, falling from its fractured burrow in the beech limb, forsook this 

 wood and commenced boring into an oak limb lying beside it. 



Not only the limbs, but small young trees, at least of the white oak, are sometimes 

 felled by these insects; in which cases the worm, instead of cutting the wood off 

 transversely, severs it in a slanting or oblique direction, as though it were aware the 

 winds would prostrate a perpendicular shoot more readily by its being cut in this 

 manner. 



The larva grows to a length of 0.60, and is then 0.15 thick across its neck, where it 

 is broadest. It tapers slightly from its neck backwards, the hind part of its body 

 being nearly cylindrical. It is a soft or fleshy grub, somewhat shining and of a white 

 color, often slightly tinged with yellow, its head, which is small and retracted into 

 the neck, being black in front. It is divided, into twelve rings by very deep, wide, 

 transverse grooves. The neck or first ring is much the largest, and shows two very 

 pale tawny yellow bands on its upper side, the anterior one slightly broken asunder in 

 its middle, and on each side beyond the ends of these bands is a spot of the same color. 

 The two or three rings next to the neck are shorter than the others, and less widely 

 separated from each other. A faint stripe of a darker color may be discerned along 

 the middle of the back, widely broken apart at each of the sutures. The last ring is 

 much narrower and more shining than the others, and is cut across by a fine trans- 

 verse line, dividing it into two parts, of which the hinder one or tip is bearded with 

 small blackish hairs, and a few fine hairs are perceptible upon the other rings. The 

 last two rings are retracted into the ring which precedes them, at the pleasure of the 

 animal, whereby this ring becomes humped and swollen ; and it appears to be chiefly 

 by thus enlarging the end of its body that the worm holds aud moves itself about in 

 its cell, its feet being so weak aud minute that they are scarcely perceptible and can 



