Small Farms

Eradication of tomato potato psyllid not feasible

Image credit: WA Department of Primary Industries and Regional Development

The Tomato Potato Psyllid National Management Group has advised that it is not technically feasible to eradicate the tiny sap sucking pest from Western Australia, where it was first found earlier in 2017.

Now, a plan is being developed to manage the pest, to limit its further spread and the impact on growers in other areas of WA and in other states and territories. Since the detection of tomato potato psyllid, interstate movement controls for risk material have been in place and continue to apply.

Overseas, the psyllid has been associated with the spread of a serious plant disease known as ‘zebra chip’ in potatoes. So far, the organism that causes zebra chip, Candidatus Liberibacter solanacearum has not been found in Australia. Surveillance is being done to confirm its absence.

Growers: please check your plants

It doesn’t matter if you are a commercial grower or only keep a few plants in your backyard, everyone who grows potato, tomato, eggplant, capsicum, chilli, tamarillo or sweet potato plants should check their plants for the tomato potato psyllid.

More information about the psyllid, including photos to help you identify it, is available on the WA Department of Primary Industries and Regional Development website, and the PHA website. The tomato potato psyllid and symptoms of zebra chip in potatoes are described below.

In Western Australia, if you think the psyllid may be present in your plants, you should still report this to the Exotic Plant Pest Hotline on 1800 084 881 or you can use the MyPestGuide reporting App.

If you suspect you have seen the psyllid outside of Western Australia, you need to contact your state or territory department of agriculture or primary industries. You can do this by phoning the Exotic Plant Pest Hotline on 1800 084 881.

Industry body AUSVEG has appointed a dedicated coordinator, Alan Nankivell, to help growers to manage tomato potato psyllid. Vegetable growers who need biosecurity advice can also contact AUSVEG Biosecurity Officers Jessica Lye or Callum Fletcher.

Movement conditions

Even though the psyllid is now established in parts of Western Australia, it’s important to control the tomato potato psyllid and prevent its spread to non-infested areas. It can spread through the movement of tomato, capsicum, eggplant, tamarillo and other Solanaceous plant material. It can also occur on the Convolvulaceae plant family, which includes sweet potato. It can disperse through natural pathways such as flight and on the wind.

The Quarantine Area Notice currently remains in place for the Perth metropolitan area and surrounds to help prevent the spread of the psyllid.

States and territories have proposed a consistent approach to movement restrictions that will apply to risk plants and plant material produced in Western Australia.

If you are planning to move host material interstate you need to check with your state or territory department of agriculture or primary industries to see if any of these restrictions affect you. You should check the Australian Interstate Quarantine website before ordering or transporting plants or plant material from Western Australia. For example, see WA ICAs 60, 61 and 62 that refer to the inspection of strawberries for the psyllid, packhouse washing of carrier produce, and treatment and inspection of nursery stock.

Restrictions on the movement of host plants and products also apply to travellers. More information is available in the latest edition of the booklet Australian Interstate Quarantine: A Traveller’s Guide.

About tomato potato psyllid

Tomato potato psyllid (Bactericera cockerelli) adults are about 3mm long. The body is brownish and has white or yellowish markings on the thorax and a broad white band on the abdomen. Their wings are transparent and held vertically over their body.

When it’s present in a crop, the noticeable signs of the tomato potato psyllid include:

  • Insects jumping from the foliage when disturbed. Adult psyllids are sometimes called ‘jumping plant lice’ as they readily jump and fly when disturbed.
  • Severe wilting of plants occurs when there are large numbers of psyllids feeding.
  • Yellowing of leaf margins and upward curling of the leaves.
  • White sugar-like granules that are excreted by adults and nymphs. These granules coat the plant leaves and stems, and can lead to the development of sooty mould.
  • Honeydew and psyllid sugar make the plants sticky and plants often appear dirty.
  • Shortening of stem internodes occurs.
  • The death of the stem is similar to other potato and tomato disorders.

The tomato potato psyllid is a significant production pest in other countries where it is present, which includes the USA, Central America, New Zealand and Norfolk Island (which is an external Australian territory).

About Candidatus Liberibacter solanacearum (which is not found in Australia)

Candidatus Liberibacter solanacearum is a bacterium associated with ‘zebra chip’ disease in potatoes.

Zebra chip disease results in reduced crop yield and crop health, stem death, yellowing of leaf tissue, and misshapen tubers.

Symptoms of the Candidatus Liberibacter bacterium on potatoes, tomatoes, capsicum and chilli may look similar to other plant conditions, so growers are urged to be vigilant for the following symptoms:

  • In tomatoes, plants may become stunted or abnormally elongated. Leaf curling and yellowing occurs on the foliage. The fruit develops unevenly. Tomatoes may be misshapen or no fruit is produced, or there is an over-production of small, non-commercial grade fruit. Symptoms vary in severity between cultivars.
  • In capsicums and chillies, parts of the plant may die back. In foliage, leaves become misshapen, pale green or yellow with spiky tips and leaf stalks appear stunted. Flowers may drop prematurely. Symptoms vary in severity between cultivars.
  • Symptoms of zebra chip in potatoes include the plant having shortened internodes and aerial tubers may develop in the leaf nodes. Potato tops are likely to be smaller than normal. The foliage turns yellow and may have a burnt or purplish appearance.
  • Stems may die completely but regrowth from the base may occur. Tubers from affected plants may have small stalked tubers protruding from the main tuber, called ‘chaining’, and when cut may show internal browning of the vascular ring or brownish streaks along the medullary rays.

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