Page:The Zoologist, 1st series, vol 1 (1843).djvu/365

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Insects.
337

caterpillar, which had been unknown to the present generation, until two or three years before. In one instance which I particularly noticed, the insects apparently commenced operations from near the hedge, and marched regularly across the field, not leaving the smallest particle of green upon the turnips behind them, and eating entirely even into the crown of the root, which consequently did not shoot again. After thus destroying a certain portion of the crop, they suddenly stopped, and the remainder of the crop was uninjured. The annoyance from these insects lasted, it may be remembered, a very few years, and then ceased, as it had begun, all at once. I can recollect other instances of the kind. Several years before, the whitethorn hedges of a particular district (many miles in extent), which are there very numerous, and very neatly maintained, were infested by a peculiar species of caterpillar to such a degree, that by the time the vermin were ready to change, not a single green leaf remained, unless a bramble or other plant protruded through the hedge, since they would touch nothing but whitethorn. Numerous remedies were tried, but produced no perceptible diminution of the insects, until, after thus prevailing three or four years, they suddenly vanished, and where myriads formerly existed, hardly one could be found. The caterpillars, when changing, suspended themselves in clusters within a web, and, previously to their disappearance, I discovered that these clusters were almost invariably filled with maggots, which had penetrated the cases of the aurelia and devoured them. The maggots greatly resembled those found in flesh, only being smaller. About the same period the oaks in the district suffered a similar visitation, though not for so many years; the tender leaves being so completely destroyed, that the trees resumed their wintry aspect. I think this moth, when it ceased to be very abundant, did not disappear so completely as the preceding. Also in the year 1840, if I recollect rightly, the farmers in some parts of Oxfordshire and Berkshire, received great injury from the immense multitudes of cockchafer grubs, which attacked their turnips, completely devouring the roots, and gradually extending over the fields, to the total destruction of the crops. A farmer, one of the sufferers, told me, that he had found as many as (I think) seventeen or eighteen grubs under a single turnip; and I witnessed that it was impossible to pull up one, without discovering a large number of the vermin in and beneath it. How abundant the mature cockchafers had been previously, and were afterwards, I am not aware; but the ravages of the larvae to such a serious amount were confined, I believe, to the season I have alluded to.—Arthur Hussey; Rottingdeane, Sussex, July 22, 1843.

Note on the blighted appearance of the Oaks, &c. I would refer your correspondent the Rev. F.O. Morris (Zool. 272), to a note of mine in 'The Entomologist' (Entom. 157), where I have stated what I saw had been done to the oaks and beeches in the New Forest; and I have no doubt that the blighted appearance of the oak and ash trees in Yorkshire proceeded from a similar cause.—J.W. Douglas; 6, Grenville Terrace, Coburg Road, Kent Road, September, 1843.

"Orchestes Quercûs. During a visit to the New Forest from the 8th to the 13th of June, I was struck with the brown appearance of the oaks; and on examination I found that nearly every leaf contained between its cuticles a larva of an elongate, flattened form, which had eaten the parenchyma of half the leaf, and by destroying its vitality made it seem as if it had been scorched. About the concavity formed by the separation of the upper and under skins of the leaf, the larvae wriggled with much activity when shaken or disturbed. In the majority of the leaves which I examined, the larva? had become pupae, and in a few days pupae only were to be found. These re-

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