Exotic plant pests - grape phylloxera

Officers of Biosecurity, and Horticulture and Forestry Science.

What is it?

Phylloxera, Daktulosphaira vitifolia, is a small sap sucking insect related to aphids that infests grapevines. It is a significant issue for grape growers due to production losses and death of vines associated with its presence, as well as the quarantine restrictions imposed on grapevine material movement from infested areas. Its seriousness can be demonstrated by the fact that it almost wiped out the French wine industry in the late 1800's through the destruction of millions of hectares of vines. The original grape industry at Geelong was decimated by phylloxera and has only recently been re-established after several decades of no grape production.

So, before you bring grape plant material, fruit, vineyard machinery and soil into Queensland ensure you have met the Queensland quarantine regulations, otherwise you place the industry at risk and you could be prosecuted. See below for restrictions.

Quarantine protects Queensland grapes

Phylloxera is native of north America from where it spread to Europe and then to many of the grape growing regions of the world in the late 1800's. Through rigorous quarantine enforcement Australia is one of the few countries that has maintained its main vineyard regions free of the pest. Vineyards that are infested with phylloxera in Australia are quarantined in quarantine areas in New South Wales and Victoria. In Queensland, the pest once existed in several suburbs of the north Brisbane area and was last detected in 1967. Surveys conducted in the Brisbane area since that time have not detected phylloxera and Queensland is now considered to be free of the pest.

Queensland restrictions

Each state has quarantine restrictions to protect their individual grape industries and Queensland restricts the import of grapevines, grape products, viticultural equipment, and soil (in which a grapevine has been growing) which can easily carry the pest. Imports of these risk items from anywhere in Australia must be accompanied by a plant health certificate stating that they originated more than 40 kilometres from an outbreak of phylloxera. Imports from within 40 kilometres of an outbreak are totally prohibited without an inspector's approval being issued from the Queensland Department of Primary Industries and Fisheries (DPI&F). Stringent phytosanitary conditions would be attached to this approval.

For more information about the requirements go to Summary of Plant Entry Conditions for Queensland or contact the DPI&F Business Information Centre (13 25 23). Failure to comply with these requirements can result in prosecution.

On farm prevention

One of the most important on-farm prevention measures is to exclude visitors, vehicles and other equipment from vineyard areas, unless appropriate disinfestation procedures have been observed or plant health certification provided. Signage at the entrance to the property outlining the basic biosecurity requirements is helpful in reminding visitors and staff of their obligations. Check that any grape plant, machinery, equipment or grape material that has come from interstate are accompanied by appropriate certification. If no certificate is provided with the item, don't allow it on to your property and report the problem to DPI&F. Any item of equipment, machinery or footwear should have soil and vegetation removed before use in vineyards.

Record significant movements of risk items on to your property in a diary and check your vines on a yearly basis for the presence of phylloxera.

Have you seen phylloxera?

Early detection of phylloxera is vital to ensure that the pest is contained and does not impact on our valuable grape industries. You can help by looking for and reporting any suspicious symptoms to DPI&F.

What to look for

The initial signs of a possible phylloxera infestation include a small area of weakened vines, showing premature yellowing, in an other-wise healthy vineyard (Figure 1). By the time these symptoms show, the insect has normally been present for 2-3 years, but at a level that is very difficult to detect. The best time to look for phylloxera is when populations are likely to be at their peak during mid to late summer (November to March).

Phylloxera reproduce most successfully on healthy root systems; dead and weakened vines will often have very low populations. When searching for a suspected phylloxera infestation in your vineyard, it's best to look for the pest at the border of the damaged area, on vines just showing the first signs of decline.

By Carefully digging up a number of roots within 0.5m of the soil surface, you can inspect new fleshy growth on fine, feeder roots for galls (small swellings), the symptoms of phylloxera feeding (Figure 2). Root tips infested with phylloxera are club-shaped or form hooks and galls may be white or yellow, turning brown later on. If phylloxera is present, a 10X hand lens or greater will be needed to see the small (0.7 to 1.0 mm long), oval shaped, soft bodied adults, which can vary in colour from green to brown or orange (Figure 3). Each female can lay as many as 400 eggs which, when newly deposited, are lemon yellow, oval, and about twice as long as they are wide. Nymphs resemble adults except they are smaller.

Damage

The galls caused by phylloxera eventually cause the death of the rootlet they form on as they impair the vine's ability to absorb nutrients and water, causing a decline in vine vigour and productivity. As the infestation progresses, early-infested vines towards the centre of the infestation will become weaker and eventually die. The area of infestation will gradually increase in size. Its progress and effect will be dependent on variety, vine age and vigour, soil condition, and drainage. Infested vines live longer in fertile, deep, well-drained soil than in shallow soil or soil with poor drainage. Phylloxera is generally less damaging on sandy soils, so the symptoms may not be as pronounced or severe.

Management

There is no method or chemical available which will eradicate phylloxera from an infested vineyard once infested. Planting vines grafted to a resistant rootstock and quarantine regulations to contain the distribution of phylloxera are the only effective means of control.

Further information

• If you think that you may have seen a phylloxera, contact a Plant Health Officer at your nearest DPI&F office or the DPI&F Business Information Centre on 13 25 23 (free call) for advice on what to do next.
• DPI&F's Biosecurity website

Acknowledgment

Photographs and images provided by the Department of Primary Industries, Victoria.

Information contained in this publication is provided as general advice only. For application to specific circumstances, professional advice should be sought. The Department of Primary Industries and Fisheries Queensland has taken all reasonable steps to ensure the information in this publication is accurate at the time of publication. Readers should ensure that they make appropriate inquiries to determine whether new information is available on the particular subject matter.

Last reviewed 28 April 2006