DPIRD entomologist Svetlana Micic said after recent rain, this is the perfect time to bait for snails

Department of Primary Industries and Regional Development (DPIRD) entomologist Svetlana Micic said now was the perfect time to bait.

There are three main snails that damage broadacre crops in WA - two species of round snails (Vineyard snail and White Italian snail), and one species of pointed snails (Small conical [pointed] snail).

Good management in autumn will decrease the risk of snail contamination of harvested grain.

Ms Micic said management of snails required a long-term strategy, with no 'silver bullet' existing to eradicate snails quickly.

She said management practices that can be applied in autumn for small conical snails included spraying summer weeds and/or windrow burning, and then baiting prior to seeding.

While seed cleaning and using a snail roller to crush the snails will effectively remove snails from harvested grain.

"These practices ensure paddocks are bare prior to baiting and the snail has no alternative green food sources to distract them from eating the baits," Ms Micic said.

Trial camera footage has revealed that snails are more active with higher humidity and at night, with movement less dependent on temperature.

South Stirling grower Alaina Smith said small pointed snails had been present on her farm for 30 years but only noticeably caused crop damage 15 years ago.

Snails were initially located around sheds and areas of exposed limestone.

"Small conical snail numbers increased 15 years ago corresponding with a larger cropping program being put in and a decrease in sheep, increased liming, increased stubble and earlier sowing of canola providing a feed source," Ms Smith said.

Ms Micic said despite a dry summer, a 'green bridge' consisting of mainly grasses and brassica weeds was present in the southern coastal parts of the State.

The green bridge is any plant material such as crop volunteers and weeds growing out-of-season that can act as hosts of pests and diseases, allowing them to move from one season's crop to the next.

Pests that growers may need to monitor, depending on their location, include diamondback moth, Russian wheat aphid, green peach aphid, redlegged earth mite, lucerne flea, weevils, vegetable beetles, slugs and snails.

Ms Micic urged growers who see unusual pest activity in paddocks to identify pests properly before implementing spraying programs.

"If you see anything unusual in your crops, please identify it and make sure you get it right before you spray," she said.

"If you do choose to apply control measures, consider the pests you're not targeting as well as the ones that you are, to reduce the unnecessary exposure of non-target pests to chemistry to which they can evolve resistance."

DPIRD has a free insect identification service to which growers can submit photos or send samples of pests for correct identification.

DPIRD senior research scientist Dr Ian Foster said rain events in late March were consistent with Bureau of Meteorology modelling.

"For a lot of the eastern grainbelt and for parts of the north, it is already wetter than average for March, but depending on how the rain arrived, there may have been significant run off," Dr Foster said.

Overall, this autumn is around twice as likely to be drier than average, according to the bureau's rain outlook, and modelling for winter indicates it is likely to be drier than average as well.

"This doesn't mean there will be no rain, but it's likely rain will be patchy, and there may be big gaps between rain events," he said.

This information was delivered at two PestFacts WA webinars, made possible by investment from the Grains Research and Development Corporation (GRDC) and DPRID as part of the Integrated Pest Management (IPM) for Grains program.