Hazelnut mite

The hazelnut mite (Tetranycopsis horridus) was first detected in Australia in 2016, in Victoria's north east and near Melbourne.

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
• 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
• 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.

Damage done by hazelnut mite

Hazelnut mites cause conspicuous white or yellowish feeding spots throughout the forests of hazel.

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.

What the hazelnut mite affects

Hazelnut mites have been mainly reported feeding on hazelnuts.

Growers should be aware that reports of the mite have associated it with:

• walnuts (Juglans sp.)
• beans, pine (Pinus sp.)
• willow, oaks (Quercus sp.)
• alder (Alnus sp.)

Some hazelnut varieties appear to be more susceptible than others.

Controlling hazelnut mites

It is the responsibility of landowners to manage this pest on their property.

Chemical control

Chemical control is often one of the methods available for plant pests as part of an integrated pest management program. More information is available from:

• your local nursery
• cropping consultants
• chemical resellers
• the pesticide manufacturer.

For information on currently registered and or permitted chemicals, check the Australian Pesticide and Veterinary Medicine Authority (APVMA) website.

Always consult the label and Safety Data Sheet before using any chemical product.

How to help prevent spread

Before leaving a host tree location, check for signs of the pest on your:

• clothing
• machinery
• tools.