Slugs
These molluscs are only too well known to everyone, because of the injury done by them to almost all kinds of garden produce. They are especially partial to young, newly-opened leaves of salad plants, e.g., Lettuce; but they also eat holes in Carrots, Turnips, and other fleshy roots, and are frequently very troublesome among flowers, not only in borders, but also when potted. Slugs are far less frequently seen than might be expected from their extreme abundance, because of their habit of living concealed, during dry weather, by day, and coming out only after a shower, or at night. Several species are very common. The more important and destructive of these are the following: Arion ater, the Black Slug, is usually more common by roadsides and in waste places than in gardens; this animal is usually black, though sometimes reddish, but its form and general aspect are easily recognised, whatever the colour. A. hortensis, the Garden Slug, is also common, but is smaller and more slender, and shows grey stripes lengthwise. Limax maximus is our largest Slug, some specimens being 6in. long when stretched out. This species, when full grown, is easily known by its size, but is not abundant anywhere, though more common than it seems. It is spotted and streaked with black. L. flavus, the Yellow Slug, and L. agrestis, the Field Slug, are very common all over the country; and L. arborum, the Tree Slug, and L. Sowerbii, the Keeled Slug, are plentiful in some parts of Britain. In all the Slugs of the genera Arion and Limax, the body seems quite naked, the shell being reduced to a small, useless vestige, inclosed in the swollen part in front, known as the mantle. By all of them, in common with most molluscs, the tongue is used for cutting their food; it is a long belt, or riband, bearing cross rows of small, horny teeth; as these are worn away on the front of the riband, it is renewed by growth behind. The number and forms of the teeth, and the development of the shell, are of great use in distinguishing the species of Slugs. They all move about by means of contractions and elongations of the broad, flat, lower surface, or foot. Remedies. Among the most effectual are baits, such as cabbage or lettuce leaves, hollowed slices of apples, carrots, potatoes, or turnips, laid near the plants that peculiarly need protection. These traps should be frequently examined, and the Slugs knocked off into ammoniacal solution, e.g., gas-water; or they may be covered with quicklime, or with wood-ashes, salt, or soot. All these latter applications require to be repeated once at least, as the Slugs resist their action by throwing out a thick coat of slime, from which they can crawl out not much the worse; but they seem unable to repeat this operation immediately, if they are covered with the materials a second time. A ring of quicklime or of soot on the soil around choice plants, forms a protection against injury by Slugs, which will not cross these substances. A successful method of destroying Slugs is to water the soil with solution of ammonia; this brings them out, and usually kills them; and, in any case, they are rendered white and conspicuous, and can easily be picked up and put into a vessel for removal. Hand-picking is most effectual in moist evenings; but this method is slow and irksome, though effectual with potted plants. Trees may be protected against the ascent of Slugs to the fruit, by tying a new horsehair rope round the stem, or by putting a layer of quicklime or soot, &c., on the soil round the trunks. The layer should be renewed as required. Slugs and Snails can lower themselves from branches, by threads formed of the thickened slime in which they are enveloped. One genus of Slugs, found in various places in the South of England, may be regarded as useful in gardens; this is Testacella, represented in England by T. haliotidea, and near Bristol by T. Maugei, which was naturalised, and has recently become abundant there. These two species live on earthworms, which they follow into their burrows. They are easily known by the existence of a small shell on the hind part of the body. See Testacella.