Slugworms
By this name are denoted the larvae of certain Sawflies belonging to the genus Eriocampa, and characterised by their slug-like form and habits. The larvae have the body covered with a secretion, which on some is white, and flaky or powdery, while on others it is dark green or black, and slimy, increasing their likeness to miniature slugs; on the larvae of some species it is yellowish, and is but small in amount. The Sawflies are small, with short, stout, black and glossy bodies. The legs are black, with the tibiae and tarsi marked with rings varying from white to a more or less yellow tint. The antennae are short, and thickened in the middle. The arrangement of cells in the neuration of the fore wings is also characteristic. The more common species are the following: E. annulipes, feeding on the lower surface of the leaves of Lime, Oak, Birch, and Willow; E. limacina (Selandria Cerasi in Miss Ormerod's "Manual of Injurious Insects"); E. ovata, feeding on Alder; and E. Rosae, the larvae of which feed on the upper surface of leaves of Roses, and gnaw away the epidermis. The larvae of E. limacina are pre-eminently the Slugworms, because of their form, dull colour, sluggish habits, dark, slimy excretion, and general appearance. The damage done by them to the leaves of fruit-trees is, at times, very great. This Sawfly is about 1/5in. long, and is black and shining, but hairy; the tibiae are yellow-brown or brownish; the wings are transparent, except a broad, smoky band in the middle. The eggs are laid on the lower surface of the leaves. The larvae, when newly-hatched, are white, but soon become greenish-yellow, with a black head. The whole body is covered with a dark, resinous secretion. In form, it is broader just a little behind the head, which is over-arched by a hump; from this point it tapers rapidly backwards. At the last moult, the resinous coat is thrown off, and the head becomes coloured like the body. The larvae feed on a great variety of trees and shrubs, chiefly among Rosaceae, e.g., Almond, Apple, Bramble, Cherry, Hawthorn, Pear, Plum, &c.; but they also live sometimes on Birch, Oak, &c. They congregate, in companies of three or four, on the upper surface of the leaf, feeding on the epidermis only; but the whole leaf becomes brown, dead, and shrivelled, and at last falls off. The larvae are very voracious, and are also very sluggish in their habits. They may be found during autumn. When full-fed, they fall to the ground, burrow into it, and there spin black cocoons for their protection while in the pupa stage. Remedies. Many remedies have been employed. The best is hellebore, mixed with water, poured from a watering-pot on the larvae. Tobacco-water, and limewater, with about 1lb. of soft soap to fifteen gallons of the fluid, are recommended; and soapsuds by themselves have been found useful. The pupae may be destroyed, in winter, by skimming the surface soil, to a depth of 3in. or 4in., from below the trees and bushes infested by the insects, and burning it. The Sawflies are sluggish, and can be caught by shaking or beating the plants over an umbrella or sheet, or tarred boards. They are abundant throughout Europe and in North America, and are said to have been introduced into New Zealand.