Glassy-winged sharpshooter

Adults

• 12–14mm long, with a large flat head and prominent eyes.
• When viewed from above, body colour is generally dark brown to black, but is pale to cream-coloured underneath.
• Wings are transparent (hence the 'glassy-winged' name) with reddish veins.
• Females may have a white chalky patch on each wing, and small ivory or yellow dots may be present on their heads.

Nymphs

• Dark grey (first and second stage) to grey (third to fifth stage).
• The cast skin from the final nymphal moult to the adult often adheres to the host plant's stem or leaf surface.

Pupae

• There is no pupal stage.

Eggs

• Individual eggs are 'sausage' shaped and laid in masses that appear as greenish water blisters beneath the leaf.

Plant stage and plant parts affected

Glass-winged sharpshooters can infest (and affect) plants of any age or growth phase (flowering, fruiting, vegetative), but prefer to feed on fresh, young growth.

They flourish in a wide variety of warm weather habitats, particularly where citrus, avocado, eucalyptus and oleander are growing, as well as in residential, park and riverine (stream-side) locations. Overseas, irrigation of agricultural land, botanical gardens and urban areas has allowed the invasion of this pest into areas that would otherwise be too dry.

Anywhere that host plants can grow, glassy-winged sharpshooter will follow; for example, glassy-winged sharpshooters have been found feeding on native plants at the highest altitudes in French Polynesia.

Plant damage

Key signs of glassy-winged sharpshooter infestation include:

• dehydration of host plant tissues (e.g. wilted foliage, dried out stems)
• less fruit
• poor quality fruit (and juice)
• a white-washed appearance on lower leaves and branches from excreted liquid*
• the presence of the insects themselves.

*Xylem fluids are not high in sugars or other nutrients, so the excreted liquid of glassy-winged sharpshooter rarely results in sooty mould production.

Glassy-winged sharpshooters look similar to slim cicadas. They could be confused with Australian leafhoppers that are a similar size and colour, with a large head and protruding eyes. An expert is needed to identify glassy-winged sharpshooter under a microscope, so all suspected sightings must be reported.

Glassy-winged sharpshooter is native to the Gulf states of the south-eastern United States of America. It is currently known to be present in:

• California, Hawaii, and the southern and south-eastern states of the United States of America
• north-eastern parts of Mexico
• Chile
• the Netherlands
• parts of the Cook Islands
• French Polynesia.

Glassy-winged sharpshooter is currently known to infest plants in the following families*: Aceraceae, Agavaceae, Amaranthaceae, Anacardiaceae, Apocynaceae, Aquifoliaceae, Araceae, Araliaceae, Asclepiadaceae, Asteraceae, Begoniaceae, Berberidaceae, Betulaceae, Bignoniaceae, Buxaceae, Caesalpiniaceae, Caprifoliaceae, Caprifoliaceae, Casuarinaceae, Celastraceae, Chenopodiaceae, Clusiaceae, Combretaceae, Convolvulaceae, Cupressaceae, Cycadaceae, Eleagnaceae, Ericeae, Euphorbiaceae, Fabaceae, Ginkoceae, Graminaceae, Hamamelidaceae, Iridaceae, Juglandaceae, Lamiaceae, Lauraceae, Liliaceae, Logaiaceae, Lythraceae, Magnoliaceae, Malvaceae, Meliaceae, Moraceae, Myoporaceae, Myrtaceae, Nyctaginaceae, Nyssaceae, Oleaceae, Onagaaraceae, Phytolaccaceae, Pinaceae, Pittospaceae, Platanaceae, Poaceae, Podocarpaceae, Polypodaceae, Proteaceae, Rosaceae, Rubiaceae, Rutaceae, Salicaceae, Sapindaceae, Sapotaceae, Saxifragaceae, Theaceae, Ulmaceae and Vitaceae (CABI.org).

*Glassy-winged sharpshooters are known to feed on many plant species on which they do not lay eggs.

Glassy-winged sharpshooter infest a wide range of horticultural, ornamental and Australian native plant species. Its known host range is continuing to expand as it spreads into new areas, especially in California and the South Pacific.

As a xylem feeder, it is able to evade host plant defences and, as a result, it appears able to feed on most plant species.

Due to the high volume of fluid intake it requires, glassy-winged sharpshooters can only survive on living host plants.

In southern California, the glassy-winged sharpshooter averages 2 generations per year. In Tahiti, multiple overlapping generations have been reported. Adults live about 2 months.

In California, egg laying begins in early winter and peaks in spring. Small, sausage-shaped eggs are laid side-by-side in masses, averaging 10 to 11 eggs. Laid just under the leaf surface, egg masses look like greenish water blisters. Eggs are often covered with a white, chalky material, which is thought to reduce egg parasitism. After the eggs have hatched, the old egg mass blister appears as a tan to brown scar.

Nymphs hatch after 2 weeks and proceed to feed on leaf petioles or small stems, while progressing through 5 moults before becoming winged adults. There is no pupal stage.

A second peak in adult activity occurs in the summer, with the new generation of adults laying eggs mid-summer.

Glassy-winged sharpshooter is a highly efficient plant disease carrying insect. Its economic impact would be significantly increased if the serious bacterial organism Xylella fastidiosa, that causes plant diseases such as Pierce's disease of grapes, citrus variegated chlorosis and phone peach disease, was also present.

Glassy-winged sharpshooters can cause significant damage to plants in their own right, with severe wilting and dehydration leading to reduced crop yields, poor fruit and juice quality and even plant death.

Natural environments may also be affected as Eucalyptus has been reported to be a host of glassy-winged sharpshooter.

Due to its wide host range, glassy-winged sharpshooter can cause significant damage in urban settings, impacting street trees, backyard fruit crops and other ornamental plants.

An interesting phenomenon known as 'sharpshooter rain' (where excess fluid excreted by large populations of glassy-winged sharpshooters feeding in trees) is a major public nuisance in Tahiti, and has led to the decline and partial defoliation of ornamental street trees.

The detection of glassy-winged sharpshooter in Queensland could cause restrictions for interstate and international trade.

Most rapid and long distance movement of glassy-winged sharpshooter is as viable egg masses in nursery plant stock, or in fresh fruit cartons (e.g. citrus or grape).

Adult glassy-winged sharpshooters are strong flyers and can move rapidly from plant to plant. Nymphs are wingless and cannot fly, but can distribute themselves by walking and jumping through the canopy or dropping from plants and walking to new hosts.

The Australian Government closely regulates and approves importation of host plant material that may be infested with glassy-winged sharpshooter, including monitoring for illegal plant movement. This helps to prevent the introduction of exotic pests into Queensland.

The best time to check for glassy-winged sharpshooter is when plants are actively growing (usually spring and summer), as this is when insect numbers are likely to be highest.

Check host plants for wilting foliage and dehydrated stems. Look for:

• large leafhopper-like insects sitting on leaves and stems
• patches of watery or white residue that results from the insects feeding (their waste products)
• eggs on the underside of leaves
• nymphs and adults on leaves, stems and branches
• cast skins from the final nymphal moult on stems or leaf surfaces
• evidence of 'sharpshooter rain' underneath trees.

In commercial settings, insect traps (e.g. yellow sticky cards) can be used to monitor for glassy-winged sharpshooters and other exotic pests.

Refer to Plant Health Australia for advice on how to monitor commercial crops for exotic pests, including glassy-winged sharpshooter.

Report suspected glassy-winged sharpshooters to Biosecurity Queensland immediately on 13 25 23 or contact the Exotic Plant Pest Hotline on 1800 084 881.

Protect your farm from plant pests and diseases:

• Protect your farm from emergency plant pests
• Understand good farm biosecurity
• Visit the farm biosecurity website

In Queensland, glassy-winged sharpshooter is prohibited matter under the Biosecurity Act 2014. Suspect glassy-winged sharpshooter must be reported to Biosecurity Queensland on 13 25 23 without delay.

By law, everyone has a general biosecurity obligation (GBO) to take all reasonable and practical steps to minimise the risk of spreading this insect pest.