Grasshoppers
Acrididae
Grasshoppers chew ragged holes in leaves and can strip seedlings and vegetables during warm, dry seasons.
Grasshoppers are medium to large jumping insects with strong hind legs built for leaping, and most species can also fly short distances as adults using two pairs of wings held flat over the back. Adults range from about 2 to 5cm long depending on species, and are typically brown, green or grey with mottled patterning that helps them blend into dry grass and soil. Nymphs (juveniles) look like small wingless versions of the adults, often bright green when young, and grow through several moults over some weeks, developing wing buds as they mature.
Eggs are laid in pods pushed into the soil, often in untilled ground, pasture edges, or under lawns, where they can survive over winter or through dry periods before hatching when conditions warm up. In many parts of Australia there is one generation per year, though numbers can build up quickly after good rain follows drought, leading to localised outbreaks or, in the case of plague species, large-scale migratory swarms.
Several species are lumped together under the common name 'grasshopper' in home gardens, including wingless grasshoppers and the migratory plague grasshopper. They are most active and damaging from spring through to autumn, particularly in warm, dry weather, and tend to favour open, sunny areas such as vegetable patches, ornamental beds, and the edges of lawns adjoining paddocks or bushland.
Management relies on regular monitoring, especially in spring when nymphs first emerge, since they are easier to control while small and before they can fly. Removing weeds and long grass nearby reduces egg-laying sites and shelter, and physical barriers such as fine netting can protect vulnerable seedlings and vegetable crops during peak activity periods.
How to identify
- Chewed foliage: ragged holes or entire leaves stripped from the edges inward, often starting on the outer parts of the plant.
- Seedling damage: young plants can be chewed off at ground level or defoliated completely overnight during heavy activity.
- Skeletonised leaves: in severe cases only the tougher veins remain, giving leaves a lacy appearance.
- Visible insects: adults and nymphs are usually easy to spot on the plant or hopping away when disturbed, especially in the warmer part of the day.
- Field check: walk through affected garden beds or lawn edges in the late morning; disturbed grasshoppers will jump or fly a short distance, confirming their presence, and small green nymphs can often be found low in grass or on leaf undersides.
- Lookalikes: crickets cause similar chewing damage but are usually darker, more active at night, and have much longer antennae than grasshoppers, which have short, thick antennae.
