Ascension.—

The small garrison at Ascension is almost entirely dependent for vegetables upon those which are raised in the island. The following report, which was transmitted by the Admiralty to Kew for advice, revealed a state of things which called for very serious consideration: "Three acres of cabbage and one acre of Kohl-Rabi were planted out in the weather gardens and promised to be a fine crop up to the end of November (1877), when they were attacked by the caterpillars and black grub in such numbers as to render it impossible to save them; this has been a great loss, as the cabbage would have supplied the island for some months; now only a few of the most forward will be fit for use . . . . The caterpillars and grubs are now so numerous that it is useless to put in any crops in the outlying gardens, the pastures are also alive with them, and they are doing much damage to the young grass.

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"Five acres of land in the sheep-walk gardens have been prepared for planting sweet potatoes, &c., but the caterpillars have so damaged the young vines as to prevent any cuttings being taken from the plants saved for the purpose."

The first thing to be done was to ascertain the exact nature of the insects which did the damage. Acting on this suggestion, the Admiralty obtained and transmitted to Kew a collection of the larvæ and mature insects, and these were submitted to Mr. M'Lachlan for identification. He reported that it was probable that all had been introduced into Ascension, and that most of them were species of wide distribution.

The most mischievous kinds he considered to be the following; they are all Noctuid moths:—

Agrotis segetum, extremely common in Europe and very destructive. Found also in India, Cape of Good Hope, &c., &c. The moth is nocturnal, as is also the larva, the latter retiring into the earth during the day. This is the most to be dreaded on account of its abundance and concealed mode of life.

Prodenia retina, a moth of very wide distribution. There does not appear to be any record of its larva; having appeared in sufficient numbers to be injurious.

Plusia aurifera, a common African species.

Plusia U-aureum, the Ascension insect cannot be separated from that of the North of Europe.

Leucania, apparently identical with L. Loreyi.

It is noteworthy that the island of St. Helena has long been infested with similar insect pests, which, indeed, allowing for divergence of entomological determination, might even be identical with those of Ascension. Mr. Melliss informs me that the green caterpillar of Plusia aurifera, and the brown caterpillars of Leucania extranea and Prodenia testaceoides, are abundant in St. Helena, and are at times very destructive of vegetation, especially cabbage and Kohl-Rabi crops. In that island young broods of the common barn-door fowl and domestic duck are found useful in destroying these caterpillars, which they devour greedily. The black grub of St. Helena is Agrotis obliviosa; at times, particularly after one or more dry seasons, this is exceedingly destructive to crops. "The grubs," Mr. Melliss states, "are seldom seen above ground, but just beneath the surface they voraciously attack the young stems and shoots of vegetation. The earth-coloured moths are nocturnal in their habits and therefore are seldom seen. Both grubs and moths are of an exceedingly sluggish disposition, and do not readily migrate. General Beatson found that the best mode of ridding the land of them is to starve them by a clean fallow during the warm dry weather."

Various opinions were obtained as to the kind of birds which might be introduced into Ascension to keep the insects in check. The island being treeless, rooks would be unlikely to thrive. Sparrows also would be useless, because the grubs are subterraneous and too large for them to feed upon. The general agreement was that starlings would be most useful. Mr. Bartlett, of the Zoological Society, reports:—"No bird would answer better; they can be obtained in the spring in largo numbers; they are very hardy and easily kept on the voyage, and will thrive in any climate where insects are abundant." If the common starling failed, that known in Mauritius as the martin (Acridotheres tristis) might be tried.

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Later in the year we were again applied to with regard to a beetle which was found very destructive to grape vines imported into Ascension from S. Africa. The specimens were submitted to Mr. M'Lachlan, who obligingly furnished a report upon them, from which I extract the following remarks:—"Mr. F. P. Pascoe, a specialist in exotic Curculionidæ., informs me that they belong to the genus Siderodactylus, which is peculiarly South and West African, and of limited extent. He considers the species not to have been previously noticed, and has named it S. ornatus. So far as I am aware, nothing has been previously recorded of the habits of the genus. The larvæ probably feed underground at the roots of herbaceous plants, and undergo their transformation in the earth. As remedies it might be desirable to dust the vines with powdered sulphur or with Paris Green, so much vaunted as a preventative against the attacks of the Colorado Beetle in America; or the beetles them-selves might be collected on sheets or circular nets placed round the vines, after being dislodged by a shake or sudden blow on the lower part of the stem."