Important: Safety Warning
This page recommends pest-control substances such as arsenic compounds, strychnine, or cyanide — in some cases applied to food crops. These substances are lethal to humans and animals, and their use is now banned or strictly controlled.
This information has been left in for historical purposes but should not be acted upon.
Vine Slug
The name popularly given, in North America, to the larva of the Grape-vine Sawfly (Selandria Vitis), which occasionally almost strips the leaves off the Vines in vineyards in the United States. The perfect insect has four wings, which are smoky-brown, but semi-transparent, with brown veins. The thorax is red, the rest of the body black, and the fore legs and lower side of the other legs pale yellow or whitish. The female is 1/4in. long, the male rather shorter. The females lay their eggs in small clusters on the lower surface of the leaves at the tips of the shoots, in the spring and early summer. The larvae feed side, in groups of fifteen to twenty. Beginning at the edge of a leaf, they eat inwards, with great regularity of rank, till they reach the leafstalk; then they eat the next lower leaf, and so on down the shoot. The full-fed larvae are a little more than 1/2in. long, and are thickest a little behind the head, thence tapering, backwards. They are pale yellow, with darker or greenish backs. Each ring bears two cross rows of minute, black dots The head and the tip of the last segment are black. At the last moult they become entirely yellow, and, crawling down to the soil, burrow into it, and form small, oval, earthen cocoons. In a fortnight, the autumn brood of Sawflies emerges, and from their eggs a new brood of larvae is hatched.
Remedies. These insects have not been found in Europe, but may be brought from America with Vines. If introduced, the infested Vines should be sprinkled with Hellebore powder (1/2oz. in 1 gal. of water) or Paris Green (half-a-teaspoonful in 1 gal. of water).