This section is from "The Horticulturist, And Journal Of Rural Art And Rural Taste", by P. Barry, A. J. Downing, J. Jay Smith, Peter B. Mead, F. W. Woodward, Henry T. Williams. Also available from Amazon: Horticulturist and Journal of Rural Art and Rural Taste.
A communication from Mr. James Mathews (now of Knoxville, Iowa), relating to his remedy for the Curculio, is too lengthy for our limited pages, and as it still does not reveal entirely what the secret is, we must be excused for giving only the substance of what he now relates. Reasons of his own induce him still to decline to make his "discovery" public. The committees to whom it was confided were unable to agree, and never formally reported. A new field of cultivation in Iowa will afford him opportunity for further experiments.
A Mr. Hobbs assures him he has been successful, and is willing so to state it to inquirers; residence, Randolph, Crawford County, Penn. He thinks improvements may be made.
Mr. M. has studied the "Turk's" habits, and he is satisfied that "the Curculio does not migrate during its depredating season. It fixes its abode under the tree; it rises from thence by the aid of its wings (which cannot be seen by the naked eye except when they are protruded for this purpose) perpendicularly to the branches holding the fruit. When the eggs are deposited, it descends again to its lodgment or burrow, and so on from day to day. That it cannot fly horizontally, I do not maintain; I only allege that, during its laying season, it remains stationary, except as previously stated. It does not eat the fruit, the deposit of the eggs being its object;" and all theories, he thinks, point to this fact.
A pavement as extensive as the limbs is a remedy, as it leaves no burrow. This does not prevent the insect from flying from a contiguous tree, and depredating, if such were its habits. Let a pig-pen be built around as large as the pavement would be, and a single hog will save the crop; not because the hog could prevent the insect from flying from an adjacent tree to the one inclosed, but because his habitation would be destroyed by the rooting. Again: on a given tree overhanging a pond or stream, the result is the same.
In the Horticulturist for November, 1856, Mr. Gardener, of Virginia, gave a remedy which, Mr. M. thinks, assists his theory. It was to remove the soil from around the tree as soon as the insect is noticed or begins to work; taking the earth five inches deep, it was wheeled away and scattered about, thus destroying (says Mr. G.) the enemy. But Mr. Mathews thinks he gives an erroneous reason for a veritable remedy, and protests against the conclusion; for a wheelbarrow load of young tortoises, whose shells had become perfectly hardened by age, could be as easily destroyed in the same way. The enemy was only removed from their rendezvous, and their habitation destroyed, the quarters from whence alone their work is carried on; they were not destroyed, and if they could fly, they would have returned. A plank floor, cement floor, and shaking into sheets for small trees - all these answer to a limited extent, but these are too troublesome and expensive, and a hog is offensive; but Mr. Gardner's is, according to our correspondent, the best plan, and will succeed.
Apply it to alternate trees, and the great question will be in a better stage for decision, and the insect, if it does not fly from tree to tree, may be destroyed in many ways.
Here Mr. Mathews leaves us still in the dark as to what he really proposes. He wishes, however, to suggest to those who have been informed of his plan, that where the depredators are very numerous, it has been found necessary to make the application (whatever it may be!) a second time.
We abridge Mr. M.'s remarks to keep the subject alive, and add our regret that the public are not yet made acquainted with "the remedy." Let us hope; and, meantime, let experimenters follow this hint (all we can get), and remove the earth five inches deep.
A new light, however, may be thrown upon this subject by the researches of Dr. Fitch, published in the recent volume of the Transactions of the New York Agricultural Society. He says: "Although this insect and its destructive habits have been so long known, we to this day remain in ignorance of its abode and condition during half the year. Most persons have supposed that some of the worms were so late in leaving the fruit that they remained in the ground during the winter, and from these come the beetles which appear in the spring; and several of the remedies have been based upon this theory. Bat that a whole generation should be brought forth abortively each summer, to perish without making provision for a continuance of their species, and that their perpetuity should be left to such a mere accident as a few individuals casually belated in coming to maturity, would be an anomaly wholly unlike anything which we meet with elsewhere".
Dr. Sanborn has asserted that at no season do they remain longer than six Weeks in the ground, and that neither they nor the perfect insects lie under the ground during the winter. Dr. Harris thence inferred that those beetles which come out the latter part of summer lurk in some place not yet discovered during winter, to come abroad again in the spring, and deposit their eggs in the fruit. Dr. Fitch thinks their lurking-place is ascertained. On a small branch of a pear-tree were found, in 1856, about thirty short, curved, or crescent-shaped incisions in the bark, similar to those made by the curculio upon fruit. On raising the bark, several little worms (commonly six in number) were found torpid, and lying in a row, side by side, with their tails toward the crescent, and their mouths in contact with the soft, green pulp of the middle layer of the bark, ready to eat their way onwards as soon as the warmth of spring awakened them again to activity. They had evidently come from eggs which had been dropped into the curved incision, were without feet, transparent, and pale yellowish, resembling little specks of gum or turpentine.
It would seem that those insects hatched the latter part of the season, finding no fruit in which they can deposit their eggs, are obliged to resort to the smooth, tender bark of the branches of fruit-trees, and the worms in these eggs repose in, not under, the bark through the winter, and produce the spring beetles which annoy the cultivator so sadly.
If this opinion (says the doctor) as to the winter quarters of the curculio proves to be correct, it may lead to most important results, as he thinks that, allowing for all casualties, it is probable that a hundred beetles might have been matured from the short piece of limb examined, and which was only four and a half inches long, and less than half an inch thick. The worms were only covered by the epidermis and thin outermost layer of the bark; so that soft soap, or some other alkaline substance, applied externally there is little doubt would penetrate through this covering, and destroy the tender brood.
If the winter retreat of this enemy can be thus discovered on trees whose fruit has been destroyed, by the mark he places upon the bark, an effectual remedy may be applied with greater ease. Dr. Harris propounded this theory in his first edition, but abandoned it. Dr. Fitch now resuscitates it, and we give it in the hope that it may be verified by careful observers the coming plum season.