Leafhoppers

Leafhoppers are small, elongated, wedge-shaped insects, usually only a few millimetres long, that hold their wings roof-like over the body. Colours vary widely by species, from plain green or brown to brightly patterned. When disturbed, they move rapidly sideways or take short hopping flights, a behaviour that helps distinguish them from slower-moving sap feeders.

Signs of infestation include fine white or yellow stippling on leaves, a scorched or bronzed appearance known as hopperburn in severe cases, and small white cast skins left behind as nymphs moult.

Leafhoppers develop through incomplete metamorphosis, with wingless nymphs resembling small adults before maturing to winged adults. Females insert eggs into plant tissue, and several generations can occur within a single growing season depending on species and climate.

Many species disperse over long distances on wind currents or through seasonal migration, which is important both for colonising new fields and for spreading the pathogens some species vector.

Feeding removes plant sap and can inject toxins that cause hopperburn, distorted growth, or leaf curling, while some species vector viruses and phytoplasmas that cause more serious disease than the feeding injury alone.

Host crops include rice, maize, potato, and grape, among many other cereals, vegetables, and fruit crops affected by different leafhopper species.

Sweep-net sampling, sticky traps, and regular visual scouting for nymphs and stippling help track leafhopper presence and abundance, informing decisions about whether and when local thresholds warrant action.

Leafhopper management fits within integrated pest management, combining several tactics rather than relying on any single approach.

• Conserve parasitoid wasps, predatory bugs, and spiders
• Use resistant or tolerant varieties where available
• Manage field borders and weeds that can harbour populations or reservoir pathogens
• Monitor and use local thresholds to guide any intervention