New mite species found in hazelnut orchards

The NGINA Office received notification of a new exotic pest detection in Victoria of Hazelnut mites from our NGIV state partners.

The NGINA has not had formal notification from the NSW DPI and we are seeking confirmation from NSW DPI regarding impact of the pest to the NGI and possible import conditions which may need to be met prior to moving host plant material from Victoria into NSW & ACT markets.

The hazelnut mite (Tetranycopsis horridus) has been recently detected in Victoria's north east and within the Dandenong Ranges. This is the first time the pest has been detected in Australia.

Overseas the species has a broad geographic distribution that includes Europe (from Spain to western Russia), China, and the United States of America. Hazelnut mites have been reported as destructive to some economic crops.

The mites feed on hazelnut leaves causing discoloration. The main host is hazelnut, but it has been reported on other species including walnut, spruce, pine, and yarrow.

Additionally, Tetranychid mites (spider mites) include some important pests in agriculture and forestry and can be found feeding on many trees, including vines, hazelnut, vegetables and ornamental plants.

Growers should examine their nursery stock or groves for symptoms of white or yellowish feeding spots on the upper leaf surface and the leaf underside for black spider mites.

What does the hazelnut mite look like?

What does it affect?

Tetranycopsis horridus has been mainly reported feeding on hazelnuts; however, growers should be aware that reports of the mite have associated it with walnuts (Juglans sp.), beans, pine (Pinus sp.), willow, oaks (Quercus sp.) and alder (Alnus sp.). Some hazelnut varieties appear to be more susceptible than others.

Can I control the pest?

Currently there are no chemicals approved for use in Australia, but in Victoria off label use of some pesticides may be permitted in specific circumstances. For more information on the potential off label use of pesticides for the control of Tetranycopsis horridus contact the DEDJTR Customer Service Centre on 136 186.

What damage does the mite do?

Tetranycopsis horridus causes conspicuous white or yellowish feeding spots on the hazelnut leaf. The mites attack the hazelnut leaf, both young and mature varieties; and are found mostly on the under surface, along with its eggs and cast skins. The eggs tend to be red in colour. A few are often located on the developing nuts and the associated bracts.

How can I help?

Identify infestations early though regular monitoring and report suspected detections (see below).

Mites are easily spread by people. Before leaving a host tree location, check your clothing, machinery and tools for signs of the pest. Report any suspected detections.

Avoid introducing infested seedlings or other plant material into your hazelnut crop. Use signs to indicate to visitors the importance of following biosecurity procedures on your property.

Further information on farm biosecurity is available at www.farmbiosecurity.com.au

Report suspected detections

Report any suspected detections of Tetranycopsis horridus by phoning the Exotic Plant Pest Hotline on 1800 084 881 (toll-free).

NGINA will keep you informed of any trade barriers and surveillance to look out for this new pest. Any questions contact NGINA or NSW DPI Biosecurity - www.dpi.nsw.gov.au/biosecurity