120 INDIRECT INJURIES CAUSED BY INSECTS. 
| than as an injury to a tree or shrub; yet when too numerous they must 
deprive it of its proper nutriment, and so occasion some defect. And 
| probably the enormous wens, and other monstrosities and deformities 
! observable in trees, may have been originally produced by the bite or in- 
\ cision of insects. 
~—~Besides exterior insect enemies, living trees are liable to the ravages 
of many that are interior, These interior feeders may be divided into two 
great classes—those which bore into the hearé and substance of the 
wood, and those which feed upon the inner bark, with. the adjoining 
alburnum or sap-wood. Amongst the former the larva of a large weevil 
{Cryptorhynchus lapathi) bores into the wood of the willow and sallow, 
which thus in time often become so hollow as to be easily blown down. 
~~ The stag-beetle tribe, or Lucanide, have a similar appetite ; but the most 
extensive family of timber-borers are the Capricorn beetles*, including the 
S— Fabrician genera of Prionus, Cerambyx, Lamia, Stenocorus, Leptura, Rha- 
—e gium, Gnoma, Saperda, Callidium*, and Clytus. The larva of these, as 
soon as hatched, leaves its first station between the bark and wood, and 
begins to make its way into the solid timber (some of them plunging even 
into the iron heart of the oak), where it eats for itself tortuous paths, at its 
first starting, perhaps, not bigger than a pin’s head, but gradually increasing 
in dimensions as the animal increases in magnitude, till it attains in some 
instances to a diameter of one or two inches. Only conceive what havoc 
the grub of-the vast Prionus giganteus must make in a beam! Percival is 
probably speaking of this beetle, when, in his account of Ceylon, he tells 
us, “ There is an insect found here which resembles an immense over- 
grown beetle. It is called by us a carpenter, from its boring large holes in 
timber, of a regular form, and to the depth of several feet, in which, when 
finished, it takes up its habitation.”* Seeing the perfect insect come out 
of these holes, an unentomological observer would naturally conclude that 
the beetle he saw had formed it, and lived in it ; but, doubtless, the whole 
was the work of the grub, Of all the Coleopterous genera, there is none 
the species of which are generally so rich, resplendent, and beautiful, as 
~— those of Buprestis: these likewise, in their first state, there is abundant 
reason to believe, derive their nutriment from the produce of the forest, 
in which they sometimes remain for many years before they assume their 
perfect state, and appear in their full splendour, as if nature required more 
time than usual to decorate these lovely insects. We learn from Mr. 
1 Lewin in Linn. Trans. iii. 1. Curtis in ditto, i. 86. 
2 See Kirby in Linn. Trans, v. 250.— More than a hundred species of the Capri- 
corn tribe, many of them nondeseripts, were collected near Rio de Janeiro by Captain 
Hancock of the Foudroyant. 
5 The larva of a Callidium (which Dr, Leach has discovered to be C. bajulum) 
sometimes does material injury to the wood-work of the roofs of houses in London, 
piercing in every direction the fir-rafters (in which it most probably took up its resi- 
dence while they were growing as trees), and, when arrived at the perfect, state, 
making its way out even through sheets of /ead, one sixth of an inch thick, when 
they happen to have been nailed upon the rafter in which it has assumed its final 
metamorphosis. I am indebted to the kindness of Sir Joseph Banks for a specimen 
ef such a sheet of lead, which, though only eight inches long and four broad, is thus 
pierced with twelve oval holes, of some of which the longest diameter is a quarter 
of aninch! Mr. Charles Miller first discovered lead in the stomach of the larya of 
this insect, 
4 P. 310. 
