Tomato potato psyllid

Tomato potato psyllid (TPP), Bactericera cockerelli, is a tiny sap-sucking, winged insect that feeds on numerous plants including tomato, potato, capsicum, chilli, goji berry, tamarillo, eggplant and sweet potato.

TPP can cause severe wilting of plants and yellowing and curling of leaves when feeding in large numbers. It also transmits the bacterium Candidatus Liberibacter solanacearum (CLso) which causes the zebra chip disease in potatoes and poses a threat to other important horticultural crops.

CLso has not been detected in Australia.

TPP was first detected in Western Australia in February 2017, with the origin of the incursion unknown. It was subsequently agreed that TPP was not eradicable and a transition to management phase was endorsed. The aim of this was to mitigate the impact of TPP in Australia on market access and trade.

Current situation

TPP has now been detected in Victoria, and has been found at multiple locations within a small area on the Bellarine Peninsula.

Agriculture Victoria is investigating the situation and is implementing relevant controls to limit the spread to other areas.

TPP can spread a serious plant disease known as 'zebra chip' in potato, caused by the bacterium called Candidatus Liberibacter solanacearum (CLso). CLso has not been detected in Australia, including in the TPP found in Victoria.

Commercial and residential growers of host crops are advised to regularly check their crops for signs of TPP, which can be found on the underside of leaves.

When present in a crop, noticeable signs of TPP include:

• insects jumping from the foliage when disturbed
• severe wilting of plants caused by high numbers of psyllids feeding
• yellowing of leaf margins and upward curling of the leaves
• white sugar-like granules which coat the plant leaves and stems, and can lead to the development of sooty mould
• ants present on the plant, collecting the sugar-like granules
• stem death symptoms similar to other potato and tomato disorders.

To report the suspected presence of TPP log a report online or call the Exotic Plant Pest Hotline on 1800 084 881.

Identifying tomato potato psyllid

The psyllid is a tiny sap-sucking insect that goes through 3 stages of development:

1. Egg
2. Nymph
3. Adult

Adult TPPs resemble small-winged cicadas and are about 3 mm long (Figures 1 to 3). The body is brownish and has white or yellowish markings on the thorax and a broad white band on the abdomen. Wings are transparent and held vertically over the body (Figure 1).

Nymphs moult 5 times, getting progressively larger each time, up to 2 mm long. They are oval shaped, flattened and scale-like in appearance (Figures 1 and 2).

Psyllid eggs are less than 1 mm long and are white when first laid, then turn yellow to orange after a few hours. The psyllid can spread through the movement of plants and plant materials, including fruit, vegetables and nursery stock, and on horticultural machinery and equipment. The psyllid can also fly short distances or be carried by wind.

How commercial growers and residents can help

Commercial and residential growers of host crops are advised to regularly check their crops for signs of TPP, which can be found on the underside of leaves.

When present in a crop, noticeable signs of TPP include:

• insects jumping from the foliage when disturbed
• severe wilting of plants caused by high numbers of psyllids feeding
• yellowing of leaf margins and upward curling of the leaves
• white sugar-like granules (excreted by adults and nymphs), which coat the plant leaves and stems, and can lead to the development of sooty mould (Figure 4)
• ants present on the plant, collecting the sugar-like granules
• stem death symptoms similar to other potato and tomato disorders.

Growers are reminded that it is an offence under the Plant Biosecurity Act 2010 not to report a suspected case of tomato potato psyllid or bacterium.

Restrictions on bringing host material into Victoria

To minimise the risk of tomato potato psyllid entering Victoria, restrictions apply to movement of host material (host plants, vegetables and fruits) sourced from any state or territory unless it meets market access requirements.

Advice on moving plant products can be found:

• in the latest industry notice in the Plant Quarantine Manual
• from your local plant standards officer on 136 186 or by emailing plant.standards@agriculture.vic.gov.au.

Photo credits

All figures courtesy of the Department of Primary Industries and Regional Development (DPIRD), Western Australia.