1816

ARBORETUM AND FRUTICETUM.

PART III.

number, as inhabitants of the oak, must be added the vast quantities ofJchneumonidae, and other parasites, which feed upon the phytophagous speciesthemselves. Perhaps the estimate here given may be found to be too great,although every one accustomed to collecting knows that the oak furnishes byfar the greatest portion of his captures. Perhaps, if we give 2000 as the num-ber of oak-feeders and their parasites, we shall scarcely run the risk of over-rating the quantity. Lesser long ago said, “ Le ebene suffit a en eleverplusieurs centaines d’especes differentes.” ( 'Theologie des Insectes, tom. i.p. 199.)

The solid Wood of the oak serves for the food of various insects, chieflywhilst in the larva state. Amongst these, the goat moth (Cossus Ligni-perda, p. 1386. fig. 1233.), the wood leopard moth (Zeuzera se'sculi, p. 887.and fig. 636.), the small stag beetle (Dorcus parallelopipedus, p. 886.fig. 635.; Gyll. Ins. Suec., i. p. 67.), and the Sinodendron cylindricum(p. 1225. fig. 1048.), are occasional inhabitants of the oak. Several otherspecies of lamellicorn and longicorn beetles are also inhabitants of this tree:of these, the great stag beetle (Lucanus Cervus, Jig. 1645.) is the most abun-dant, as well as the largest. The larva of this insect (a) feeds upon the putridwood of the oak. ( Gylknhal Ins. Suec., i. p. 65.) It is a large, whitish, fleshy,grub, like that of the cockchafer (Afelolontha vulgaris); and it is furnishedwith three pairs of legs, attached to the three anterior segments. In general, itlies on one side, with the body curled up, so that the tail nearly touches thehead. The structure of the jaws of this larva is very similar to that of thecaterpillar of the Cdssus; although, in the perfect state, it is impossible todiscover two insects more completely unlike each other. When it has attainedits full size, it constructs a cocoon of chips of wood, agglutinated together,within which it assumes the pupa state, in which the immense mandibles ofthe imago are distinctly visible (b). The female pupa is, of course, destitute ofthese large jaws, these organs being but of comparatively small size in thatsex when arrived at the perfect state (e). The beetle seems to subsist entirelyupon fluids, which it laps up by means of its long pencil-like lower jawsand lip.

Trichius variabilis is another lamellicorn beetle, the larva of which feeds uponthe wood of the oak. It is occasionally found in Windsor Forest, but is of greatrarity in this country. Its larva is very similar to that of the cockchafer.A beautiful figure of the perfect insect, which is also found upon, and within,the stumps of rotten oaks, is given by Curtis. (Aril. Ent., pi. 286.)

The larvae of the longicorn beetles, on account of their generally large size,are destructive to trees ; but they are comparatively of rare occurrence in thiscountry, if we except the musk beetle, found in willows. In tropical climates,where the perfect insects attain a gigantic size, they must be as injurious asthe Cdssus larva. These large wood-feeding larvae, or some of them, at least(and it is not clearly proved which), were considered by the Romans as greatdainties, and are still greedily devoured by the negroes in many tropicalclimates. We will not quarrel with the tastes of these Acriddphagi andCampophagi, because there can be no reason why a larva, which feeds uponwood, should not be as nutritious as an oyster or a shrimp; but we willquote a short passage relative to the subject, from the observations of thecelebrated African traveller, Smeathman:—“ The larvae of all the beetles thatfeed on decayed wood seem to be rich and delicate eating; so that every forestin the torrid zone affords a man plenty of very wholesome and hearty nourish-ment, who has an instrument strong enough to cut in pieces the decayedtrees. This knowledge might have saved the lives, perhaps, of many seamenwho have been shipwrecked on desert equinoctial shores, which are generallycovered with thick woods. The very best kind of vegetable food is but poornourishment for the labouring Europeans, if not accompanied with animalflesh, or, at least, with animal or vegetable oils; and such food as seamen indistress meet with, as above mentioned, have oftentimes very acrimoniousqualities, and are dangerous, even in small quantities, to those who eat them