Slug numbers have shot up again to critical levels in many areas hit by recent rains, according to a national survey.

Growers are advised to monitor the pest carefully and use good quality pellets only where treatment is justified.

Trappings showed average slug populations reaching 30/sq m last week, according to the survey which was set up to help improve slug pellet stewardship to minimise watercourse pollution.

But growers shouldn’t rely on these results alone, says Chris Bean, technical director of UAP, one of three distributors carrying out the survey co-ordinated by slug pellet manufacturer De Sangosse.

“Don’t neglect slug monitoring on farm to identify high-risk patches which must be targeted.”

Good quality pellets are essential for the tough conditions this autumn, he adds. “Persistence is the key feature. Pasta-based pellets can be expected to last 21 days against the two to three days one can expect from standard minis.”

The slug threat, exacerbated by recent wet weather, plenty of crop debris and less than ideal seed-beds, is especially high in slow-emerging crops, says ProCam’s technical director David Ellerton.

One site in East Anglia recently recorded 28 slugs a trap, seven times the treatment threshold, he adds.

“It is important to monitor the threat and consider the most appropriate action, with environmental issues such as water very much in mind.

“Take particular care when spreading pellets close to water and on headlands. Proper stewardship of these products is essential, for good control and to make sure we have them in the future.”