Juvenile green snail (actual length about 30mm)
In September 2011, the declared exotic plant pest green snail (Cantareus apertus – formerly Helix aperta) was detected in Victoria for the first time, near Cobram in the north of the state.
The snail is native to Southern Europe and North Africa. It became established in the Perth metropolitan area in the 1980s, possibly introduced by an overseas traveller.
What is the current situation?
Green Snail (Cantareus apertus) 25km Restricted Area
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A restricted area has been declared around the infestation near Cobram - see map and Order Declaring Restricted Areas in Victoria for the Control of Green Snail (The Gazette can be found at http://www.gazette.vic.gov.au No. G 41 Thursday 13 October 2011).
Restrictions apply to the movement from this area of most plant materials, including pasture grasses, fodder (hay), vegetables, nursery stock and cut flowers.
DEPI has resurveyed the affected areas and is developing options for the eradication, containment or management of this pest.
These options will be provided to the national Consultative Committee on Emergency Plant Pests to help decide whether or not the outbreak can be eradicated.
What movement restrictions are in place?
Consignments of green snail host materials and host plants need certification to be sent interstate or elsewhere in Victoria from the green snail 25 km restricted area.
See the green snail market access conditions.
DEPI is identifying additional businesses within the restricted area that have host materials and issuing permits as required.
For further information on movement restrictions, please contact DEPI on 136 186 or email firstname.lastname@example.org
Please note that movement of fruit crops is not affected.
About green snails
Mature green snails have an olive-green shell and white flesh. They are intermediate in size between the smaller vineyard snail and white Italian snail and the larger common garden snail, rarely exceeding 25mm in shell diameter.
Green snail is similar to both the white Italian snail and the common garden snail in that it remains dormant through the summer in dry situations. However, unlike the other snails, it burrows into the soil before becoming dormant.
Following autumn and winter rains the snail reactivates itself. The eggs are laid in the soil about May or June and the young snails appear in early winter. Green snails can breed very quickly, with up to 1000 young snails found per square metre.
As this outbreak is the first time green snail has been found in Victoria, almost nothing is known about its behaviour under the specific combinations of climate, soil and crop conditions found in the outbreak area.
What plants are affected by these snails?
The green snail has a wide host range. Near Perth it has damaged cabbages, cauliflowers, lettuces, peas, beans, wheat, lupins, pasture grasses and native plants. It thrives in dense grass and seems to have adapted to the sandy soils of the Perth metropolitan area. It also inhabits areas of natural bush.
The damage caused by green snail is similar to that of common garden snail – feeding on the surfaces of young leaves, often only penetrating shallowly and leaving a ‘windowpane’ effect. Older snails eat holes in the leaves and may reduce them to veins only.
During their underground summer dormancy, green snails do not pose a risk to crops.
How does green snail spread?
Green snails spread through the movement of infested plant material eg. in hay bales, nursery stock or harvested vegetables, or the movement of soils.
What can I do to protect my crops?
For advice on controlling green snail, please contact DEPI on 136 186.
Any chemical products used to control green snail must be applied, stored and disposed of according to instructions on the container label. In particular:
- Observe specified withholding periods.
- Ensure that pets and livestock are excluded from baited areas and chemical preparation areas.
- Do not contaminate waterways with chemicals or used containers.
Who should I contact if I suspect a problem or see green snails?
If you suspect you have found green snail, please contact DEPI immediately on 136 186.
The green snail can be readily distinguished from other snails.
(both of the above species are smaller than green snail).