Adult

The adult is approximately 3 mm long, pale green with distinctive brown and black markings on the body and wings. They are very active and hop from the plants when disturbed. The eggs are laid in the leaf veins and petioles but are not easily detected even under a microscope.

Nymph

The young nymphs (left) are pale whitish-green. The older nymphs (right) have dark brown bands across the body and the tips of the wing buds. The nymphs are less mobile than the adults and are usually found under the leaves next to a leaf vein.

Cast skins

There are five nymphal stages and when each stage moults, the cast skins are left behind on the leaf, and can be mistaken for live leafhoppers.

Damage

The 'sage' leafhopper commonly damages sage, balm, basil, lavender, mint, marjoram, oregano, rosemary and thyme.

Leafhopper damage appears as white or yellow spots on the leaves which later coalesce to form bleached areas. Damage is shown on basil (close-up bottom right), on sage (bottom left), and on mint (bottom centre). On badly damaged leaves, small black faecal spots are visible (shown on mint).

Biological control agents

Anagrus atomus

Adult

A tiny parasitic wasp, less than 1 mm long,commercially available and also occurs naturally on nurseries using IPM. The wings are fringed with long hairs. Female wasps lay their eggs inside leafhopper eggs in the leaf veins or petioles. Research in this project showed that releases of Anagrus to sage and mint plants reduced numbers of 'sage' leafhopper.

Parasitised leafhopper

Parasitised 'sage' leafhopper eggs turn a dark brown unlike parasitised glasshouse leafhopper eggs which turn red (right). The sage leafhopper eggs are laid deeper in the leaf veins than glasshouse leafhopper eggs so are more difficult to see.

Red-coloured 'glasshouse' leafhopper eggs parasitised by Anagrus

The immature Anagrus develop inside the 'sage' leafhopper eggs in the leaf tissue but are difficult to see, even with a microscope or hand lens. The arrow in the photo (right) points to one of the Anagrus eyes, part of the dark body shows indistinctly.

Insect-pathogenic nematodes

Initial research in this project has shown that the insect-pathogenic nematodes, Steinernema feltiae can infect and kill 'sage' leafhopper nymphs. Infected nymphs often have a dark brown head or rear end of the body.

'Sage' leafhopper nymph (right) with dark patch at rear end, which is a symptom of nematode infection. The arrow shows a nematode released from the leafhopper body when dissected in a drop of water.