PestFacts WA

Slugs are active down south

  • Frankland
  • Mount Barker
A black keeled slug and reticulated slug
A black keeled slug (left) and reticulated slug (right). Photo courtesy of: DPIRD.

Tim Trezise (Frankland Rural) has found immature black keeled slugs present in very low levels in the Frankland area.

As part of the GRDC funded national project DAS00160, Biology and management of snails and slugs in grain crops, cameras are being used to monitor slug and snail movement in southern WA. The cameras at Mount Barker at the start of this week was showing low numbers of black keeled slugs actively moving from 10pm at night. There is no obvious damage to crops located in close proximity to the cameras. However, collections outside of the crop are finding higher numbers of immature slugs present.

Slug movement trials conducted last year looking found that the higher the humidity the more slug movement there was.

There are two slug species and three snail species that are pests of WA broadacre crops. For more information on how to diagnose snails and slugs refer to DPIRD’s Diagnosing slugs in crops and Diagnosing snails in crops.

Current slug and snail management recommendations

Slug and snail numbers should be monitored to determine whether they exceed DPIRD’s suggested threshold numbers and if they need to be managed.

Baiting now when crops have emerged will have reduced effectiveness as there is a lot of green material that provides an alternative food source for the slugs. Even bait coverage increases the likelihood of slugs or snails encountering the bait and feeding on the bait. Trials suggest 30 baits per square metre give good control.

As slugs are currently present in canola crops, growers need 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. Soil type doesn’t matter - slugs can survive hot, dry summers in lighter soils if there is enough moisture in the soil profile.

In 2019 check paddocks that had snails and slugs this season before seeding. 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. If you are patch baiting only where you are expecting slugs make sure you bait sufficient area around the patches to cover movement of slugs from these areas.

For more information on slug and snail control visit;

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