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The Pamphlet Collection of Sir Robert Stout: Volume 14

Life History

Life History.

The insects appear first upon the hop plants as small larvæ. When they have arrived at their full larval size they "moult," as the planters say, leaving their skins upon the leaves. Another moult occurs after the pupa stage, when the perfect winged page 20 insect is formed. In all of these stages the injury to the plants is continued. Pairing then takes place, and the female lays eggs and dies. It is not clear where the eggs are deposited, nor has it been ascertained whether the life of the insect is carried on by eggs through the winter, or by hibernating larvæ. Some of the species of this family deposit eggs under the rind of plants in the autumn, which are hatched in the early spring, as the Typhlocyba Ros œ. Another, Jassus sexnotatus, according to Taschenberg, lays them either in the ground or upon the roots of plants just below the surface of the ground. Harris speaks of a species, Tettigonia vitis, in America, whose larvæ retire for shelter during the winter beneath fallen leaves, decaying tufts, and roots of grass. Reasoning, then, by analogy, and from what is actually known of these jumpers, it seems certain that they are concealed in egg or larval form close to the hop plant-centres, in the ground or within the cracks of the poles, during the winter. Their continuity of existence is not carried on by means of eggs upon or under the rind of the hop plants, because these are cut down in the autumn and carried away. The plant-centres, or perennial stocks, remain, with pieces of bine upon them only a foot in length, and small pieces of bine get broken off and lie on the ground throughout the winter. Their rind shrivels up, and the eggs, if under it, would be destroyed. The poles, which remain upon the ground, stacked close to the hop plants, are said to be depositories of the insect, either in egg or larval form; for Miss Ormerod reports that a plantation was so much infested with jumpers that it was grubbed, and the poles were removed to another ground till then free from jumpers, this was soon after as badly troubled with them as the old plantation.

As its name implies, this insect, in common with others of the Cercopid œ, has wonderful powers of leaping, with hind legs disproportionately long and furnished with well developed muscles.

The colour of the perfect insect is yellowish, with markings of brown on the wings, head, abdomen, and legs, varying somewhat in position and intensity. In the pupa stage farther variations of colour may be noticed. Some specimens have been seen with crimson markings.