Don't let snails eat into your crop profits

Date: 04 Oct 2012

Small  pointed snails being held in the palm of a hand

Growers with high numbers of snails in their grain this harvest can take steps to minimise numbers of the damaging pest in next year’s crop.

They may also need to clean grain, which could be rejected if more than half a dead or one live snail is found in a 0.5 litre wheat sample, or 200 gram pulse sample.

These are some of the messages in a new Grains Research and Development Corporation (GRDC) Snail Management Fact Sheet, which advocates a year-round approach to controlling snails, which damage crops as well as contaminating grain.

Department of Agriculture and Food (DAFWA) entomologist Svetlana Micic, who helped compile the fact sheet, said identifying snail species and monitoring numbers prior to harvest and before and after control operations were essential for making appropriate management decisions.

“A rule of thumb is if snail numbers are above 20 per square metre in cereals and five per square metre in pulses and oilseeds, be prepared to deal with grain contamination at harvest,” she said.

Ms Micic said moist summers boosted snail numbers as summer weeds provided the pests with shelter, moisture and food.

“Controlling summer weeds is important as it means that snails are more likely to eat baits, which should be applied before snails lay eggs, which occurs generally in late summer or early autumn,” she said.

“In cool, moist summers, baiting pastures or stubbles after harvest in December has seen good kill rates if snails have been actively feeding.”

Ms Micic said growers needed to bear in mind that hot, dry summers did not necessarily kill snails, and that stubble retention aided snail survival.

Small pointed snails on harvested canola stalk

Small pointed snails on harvested canola stalks in

“The ‘Bash ‘Em, Burn ‘Em, Bait ‘Em’ principles of integrated snail management – outlined in the fact sheet - will help reduce snail numbers,” she said.

Ms Micic said there were increasing reports from WA growers of snails causing damage to crops and requiring control.

“Snails causing damage to WA crops are predominantly small conical snails, although round snails are also a problem at Esperance, Hopetoun and in parts of the Geraldton port zone,” she said.

“WA cropping areas where snails are most problematic include south coastal districts and some areas near Geraldton.”

The GRDC Snail Management Fact Sheet was mailed to growers in the September-October edition of the GRDC magazine Ground Cover, and can be downloaded from

The GRDC is conducting new research on baits, with a focus on juvenile snail control, including formulation testing of alternative ingredients and biological control agents.


PHOTO CAPTION: Small pointed snails harvested in canola grain. Adult snails were sieved out of the grain, but immature snails the same size as the grain could not be sieved out.

PHOTO CAPTION: Small pointed snails on harvested canola stalks in spring.

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GRDC Project code: DAW00177