Entomologists, however, have noted several instances of insect depredations upon individual trees, by a few species of the long-horn beetles, three or four in all, but these occur so rarely that they are scarcely worthy of notice as pests of the chestnut. There are also several species of caterpillars occasionally found feeding on the leaves of this tree, also some sucking bugs or tree hoppers, and two or three kinds of plant lice, but none of these have, as yet, become at all formidable enemies, or likely to become so later. But the chestnut has one enemy which is so abundant and destructive to the nuts as to call for an extended notice. I refer to the common native chestnut weevil (Balaninus carytripes, Boheman). The little fat, white, round, legless grubs, nearly or quite a half-inch long, must be familiar to every person who has handled or eaten chestnuts raised in this country, whether of the exotic or native varieties. The parents of this grub are oval-shaped beetles about one-half inch long or less; wing covers, body and legs densely covered with a short yellow down, and from the front or thorax there extends a long, slightly curved, slender snout (Fig. 36), sometimes nearly an inch in length in the females, but usually less in the males. The mouth parts are at the extreme end of this snout or proboscis, and the female, with her mandibles, it is claimed, reaches down among the chestnut spines and gnaws a hole in the husk, into which she drops an egg; and when this hatches, the minute grub cuts its way through the green husk and into the nut, the hole made in its progress closing up behind, leaving no mark or scar. Although I have taken hundreds of these weevils on chestnut trees, I never have been so fortunate as to take one in the act of ovipositing, but have come so near it as to find the ovipositor still extended as the insect crawled out from among the spines.
[FIG. 36]. CHESTNUT WEEVIL.
The chestnut weevil usually appears in great numbers soon after the trees bloom in spring, but they continue to come out all through the summer; I have occasionally found them late in September, which probably accounts for finding small and half-grown grubs in the nuts as they ripen and fall from the trees. These late grubs often remain in the nuts all winter, but the greater part escape earlier, or very soon after the crop is ripe. The grubs crawl out of the nuts and work their way into the ground to a depth of from a few inches to two feet, much depending upon the nature of the soil. Having very powerful jaws, they readily cut through a layer of leaves or soft wood, and I have known them to cut holes in sheets of dry cork. These grubs remain in the ground until the following season, then come forth in their winged or weevil stage, except the belated, broods, or those that have not reached full size in the autumn; these remain in the ground the entire summer, coming out late in the fall, or pass over until the second year, as I have proved by burying the grubs in a barrel sunk in the ground, covering the top with fine wire netting, to prevent the escape of the weevils as they emerged from time to time during the season.
As a rule, we find only one grub in a nut, of the American sweet chestnut, but in the larger varieties of the European and Japanese, two or more is not unusual, which rather favors the idea that the female weevil does possess something akin to reason, which guides her in locating stores of food available for her progeny. I have never observed that the weevils had any choice among varieties, all being subject to their attacks alike, provided all were growing in equally favorable positions. But if the trees are of different sizes, some tall and others short, some exposed to the winds and others protected, then the ravages of this pest will, no doubt, be as variable as the surrounding conditions. As the weevils emerge from the ground in spring or early summer, they will naturally seek the nuts most convenient and on the small trees, then those on the lower branches of the larger ones, while those on the upper part of the tree, where they are fully exposed to the winds, may wholly escape the attacks of these pests. This leads me to think that whoever attempts to cut off native chestnut forests, with the expectation of renewal with the larger varieties, by grafting the sprouts, will find the chestnut weevil a rather formidable enemy. I have found it so on a limited number of trees in my own grounds, that are grown from grafted sprouts near large native specimens, the weevils destroying nearly every nut; but out in the field, away from the woods, and where the young trees are scattered and exposed to the full sweep of the winds, the nuts are sound and free from insect enemies. The only remedy is to collect and destroy the weevils, which is not a serious matter where only the larger varieties are cultivated.
Diseases of the Chestnut.—I have never noticed any special disease among chestnuts, neither do I find any mentioned in European works on forestry. The nearest approach to any such malady being recorded as having appeared in this country, is found in a paragraph in Hough's "Report on Forestry," 1877, p. 470, where the author copies from Prof. W. C. Kerr, State Geologist, North Carolina, as follows: "The chestnut was formerly abundant in the Piedmont region, down to the country between the Catawba and Yadkin rivers, but within the last thirty years they have mostly perished. They are now found east of the Blue Ridge only, on higher ridges and spurs of the mountains. They have suffered injury here, and are dying out both here and beyond the Blue Ridge. They are much less fruitful than they were a generation ago, and the crop is much more uncertain."
While there is nothing said about any chestnut disease in the paragraph quoted, we only infer that the author intended to convey the idea that the trees were suffering from some endemic malady, although it may have been due to long drouths, insect depredators, or other causes. A few years later Mr. Hough, in his "Elements of Forestry," refers to the subject again, and admits that "the cause of the malady is unknown." But as chestnuts continue to come to our markets in vast quantities from the Piedmont regions, there must be a goodly number of healthy trees remaining.
Uses.—The economic value of the chestnut, as food for mankind and the lower animals, has been, and is still, so well known, that no extended dissertation or compilation of historic instances of its usefulness are required here. For almost two thousand years it has been an important article of food throughout southern Europe, and in some of the mountainous districts it is almost the "staff of life" among the poorer people, who not only use these nuts in their raw state, but roasted, boiled, stewed, and even dried and ground into flour, from which a coarse but nutritious kind of cake or bread is made. These nuts are also used in the same way by the poorer classes of China and Japan, and probably in other oriental countries. In France, Italy, Spain and Portugal, the chestnut crop is of immense importance, not only for domestic use, but commercially, because all surplus is wanted by other nations, who are ever ready to take a share, and pay a good round price for the same.
In this country chestnuts are mainly used as a luxury or a kind of pocket lunch for the children, as they are rarely brought to the table, and it is very doubtful if the American housewife, or our cooks,—unless foreign born and bred,—know anything about preparing these delicious nuts for comestible purposes. Cereals, meats, fruits and vegetables have always been so abundant and cheap in this country, that the poorest of the poor could indulge in them without stint or limit; but all this will change sooner or later, and when our population has doubled or trebled, the edible nuts must become of much more importance than now, and a roast turkey stuffed with chestnuts may figure as the ideal of gastronomic art.
As our native chestnuts are now annually consumed by the thousands of bushels, and the imported varieties by millions of pounds, and all as a mere luxury,—not a necessity nor an article which we could not dispense with without any serious inconvenience,—we may well consider what the future demand must be, and make haste to meet it with an abundant supply.