Grasshoppers

Camnula pellucidaFootnote 1

Hosts

All trees and shrubs

Appearance and Life Cycle

Description of this image follows
Clear-winged grasshopper.
Photo credit: D. L. Johnson, insectsofalberta.com

Grasshoppers overwinter as eggs in the soil, emerging as nymphs in May to June. Nymphs are approximately 3-5 mm long and resemble the adult stage, except for size and undeveloped wings. Immediately after emerging, they begin feeding on surrounding plant material. Nymphs undergo five molts (shed their skins) over a 3-8 week period, to reach the adult stage. Two weeks after mating, the females lay cream to orange-coloured, elongated eggs in the top 5 cm of soil. Each female produces an average of 250 eggs in a life cycle. Grasshoppers will continue to feed and lay eggs until cold weather kills them. In Canada, grasshoppers have one generation a year.

Damage

Description of this image follows
Adult grasshopper.
Photo credit: Drees, insects.tamu.edu

Grasshoppers are general feeders and will feed on all species of trees and shrubs, including conifers, when normal food supplies are low. Generally, grasshoppers eat only the leaves and cause no permanent damage. However, in severe cases, when conifers are completely defoliated or when the bark of young trees is girdled, damage is fatal.

Control

Because of repeated swarms, several applications of insecticide are usually required for control. Insecticides available include: carbaryl; carbofuran; chlorpyrifos; cypermethrin; deltamethrin; diazinon; dimethoate and malathion. If only a few ornamental trees are being attacked, they can be covered with burlap, wire screening or thin fabric. These coverings protect the trees, while allowing entry of light and air.

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