PestFacts WA

Avoid snail contamination at harvest

  • Myrup
Round snails on a wheat leaf
Round snails on a wheat leaf. Photo courtesy of Quenten Knight (Agronomy Focus).

Quenten Knight (Agronomy Focus) has found small pointed snails (also known as small conical snails) and round snails in the upper canopy of a Scepter wheat crop near Myrup. The snails were feeding on the flag leaf and flag -1 (leaf 2).

Growers and consultants are urged to keep an eye out for snails climbing up into crop canopies as this can pose a contamination risk when the crops are harvested. Entomologist Svetlana Micic (DPIRD) says that as a 'rule of thumb', if snails are easily seen on crop stems, grain contamination at harvest is possible.

A small pointed snail (also known as a conical snail) on a wheat leaf
A small pointed snail (also known as a small conical snail) on a wheat leaf. Photo courtesy of Quenten Knight (Agronomy Focus).

Snail movement does depend on the weather conditions. Snails are more active at night and if there has been a rain event. Grain from crops harvested during the day had less snail contamination than from crop harvested at night. 

Past snail camera footage has revealed that as weather conditions become hotter, round snails are more likely to be found moving up crop stems, whereas small pointed snails were more likely to be under stubble on the ground.

Plan for harvest now if you have snails. Consider using a stripper front at harvest or increasing the cutting height of crops such as cereals. There are options to remove snails from harvested grain. Now is the time to budget for this.

Consider farm biosecurity practices to prevent spread of snails between paddocks and properties, such as harvesting paddocks or properties with snails last.

At this time of year, ie spring, it is too late to bait.

Plan for next season’s snail management now

Growers are advised to be proactive now to determine what they will need to do next year. Now is the time to check paddocks that you will seed with canola next year for snails. Soil type doesn’t matter – snails can survive hot, dry summers. 

Before seeding in 2023, check paddocks for snails and budget to apply bait more than once but be aware that spreaders calibrated for fertiliser spreading may not be spreading the baits as far as you think. DPIRD’s SnapBait app assists with calibrating bait spreaders.


For more information on snails and their management during the season and at harvest visit;

For more information on snails contact Svetlana Micic, Research scientist, Albany on +61 (0)8 9892 8591.



Article authors: Cindy Webster (DPIRD Narrogin) and Svetlana Micic (DPIRD Albany).