Leaf Hoppers
Cicadellidae
Leafhoppers are small, fast-moving sap-sucking insects that cause pale stippled leaves and can spread plant viruses in gardens and crops across Australia.
Leafhoppers are a large family of small, wedge-shaped insects that feed by sucking sap from the underside of leaves. Adults are usually 3–8mm long, slender and tapered towards the rear, and can be green, brown, yellow or mottled depending on the species. They're quick to move sideways or hop away when disturbed, which is where the common name comes from. Nymphs look like smaller, wingless versions of the adults and are often paler or more translucent; both nymphs and adults are usually found clustered on leaf undersides.
Eggs are laid inside leaf tissue or stems, and nymphs develop through several stages on the same plant before maturing into winged adults. Development is quick in warm weather, so several generations can occur through spring, summer and autumn in most parts of Australia. Some species overwinter as eggs in bark or plant debris, while others survive as adults in sheltered vegetation.
Leafhoppers attack a very wide range of plants, including vegetables, ornamentals, fruit trees, grapevines, pasture and lawn grasses. Different species have preferences for particular hosts, but as a group they turn up almost anywhere there's soft new growth. Populations build quickly in warm, dry conditions and can be worse where there's dense or lush growth that shelters them from predators.
Management relies on regular monitoring, since numbers can build up unnoticed on leaf undersides. Encouraging beneficial insects such as lacewings, ladybirds and predatory bugs helps keep populations in check, and removing weedy hosts nearby reduces the sources leafhoppers move in from. Avoid overfertilising with nitrogen, as it encourages the soft new growth leafhoppers prefer.
How to identify
- Stippled or bleached leaves: Feeding punctures leave small pale or whitish spots, giving leaves a mottled, silvery or bronzed look, particularly along veins.
- Curling, distorted or scorched leaf edges: Heavy feeding can cause leaf margins to brown and curl, sometimes called 'hopperburn'.
- Sticky residue and sooty mould: Some species excrete honeydew, which attracts ants and can lead to sooty mould growth on leaves.
- Stunted or distorted growth: A small number of leafhopper species transmit plant viruses or phytoplasmas, which can cause yellowing, stunting or abnormal shoot growth.
- Confirming the pest: Tap or brush affected foliage and watch for small insects jumping or flying off — this is the easiest way to confirm leafhoppers rather than mites or thrips. Check leaf undersides closely, as nymphs and adults often sit there rather than on top of the leaf.
- Lookalikes: Aphids cause similar stippling and honeydew but are slow-moving and pear-shaped rather than wedge-shaped and quick to hop. Thrips damage looks silvery too, but thrips are much smaller, slender and rasp rather than suck, and won't jump like leafhoppers when disturbed.
