Grasshopper (Melanoplus spp.), Orthoptera

Grasshopper biology & life cycle

Three species of grasshoppers (clearwinged, migratory, twostriped) overwinter as eggs in the soil. Migratory grasshoppers hatch first in early May followed by the clearwinged and twostriped grasshoppers in late May. Migratory grasshopper hatching occurs until mid-July. This is the most destructive grasshopper in western Canada. The other two species are done hatching by late June. Nymphs feed for a period of 4-8 weeks with the nymphs of the clearwinged grasshoppers being around the longest. Adults of the migratory grasshopper are the first to appear from mid-June to mid-July. Twostriped grasshopper adults appear in the last 2 weeks of July and are present until September. The clearwinged grasshopper adults appear in July and August. Eggs are laid in field margins, ditch banks, closely cropped pastures, fence rows but not in cultivated fields. The migratory grasshopper prefers moist sandy soil over loam, clay or dry sand for egg laying. The remaining two species do not show a preference for different soil types.

Identifying Grasshopper

Grasshopper: larvae

Nymphs of all species resemble adults without wings. Clear-winged grasshoppers: young nymphs are dark brown to black with a distinct white back encircling the thorax. Older nymphs are mottled grey to brown in colour. Migratory grasshoppers: nymphs of this species have a mottled black appearance with black bands along the top of the thorax. Two-striped grasshoppers: nymphs are yellowish in colour but have a black stripe on at least one third of the hind leg.

Grasshopper: adult

Clearwinged grasshoppers: adults are medium-sized (23-30 mm) with colour varying from pale yellowish brown to black with a lighter undersurface. The wings have two pale stripes that converge at the tip of the forewings, and there are round to oval dark blotches on the forewing as well. The hind-wings are clear. The hind legs are pale with three narrow dark bars.
Migratory grasshoppers: adults are medium-sized (20-28 mm) and are greyish yellow to brown in colour. The hind legs are marked with a series of black bands and a pink stripe on the lower edge. The forewings are dark brown with no distinct stripes or mottling.
Twostriped grasshoppers: larger grasshoppers (28-40 mm), dark yellowish green in colour witha pair of distinct yellow stripes extending from just behind the eyes to the tip of the forewing. The hind legs are yellowish with a solid black stripe along the outer side.

Grasshopper: management

Both nymphs and adults can be very damaging and scouting along field margins should begin in June and continue until the end of August. Population levels are determined by weather conditions. Grasshopper outbreaks are preceded by 2-3 years of hot, dry, summers and dry fall. Dry weather increases the likelihood of egg and larval survival and development.