Hot weather slows spread of invasive slug species

The Iberian slug, commonly known as the killer slug, has struggled to thrive in Denmark this summer due to prolonged dry and warm conditions, experts say.

According to the Danish Broadcasting Corporation, the warm and dry weather has limited the spread of the invasive species, which prefers moist and shaded environments. Reports to the Danish Horticultural Society indicate fewer sightings of the slug compared to previous summers.

“It appears there are fewer than in other years because they haven’t had good conditions to reproduce,” said Brian Christensen, a horticultural advisor at the Danish Horticultural Society.

Senior researcher Stine Slotsbo at Aarhus University, who specializes in ecophysiology and ecotoxicology, echoed this assessment. “Overall, it doesn’t look like there are as many killer slugs as in peak slug years,” she said. “This is primarily because we’ve had a period of drought.”

Despite the current slowdown, experts warn that killer slugs remain hidden under tree stumps and in compost piles, ready to re-emerge if wetter weather returns. “If we get a wet period, we risk the slugs coming out again and bothering us in our gardens,” Slotsbo said.

She added that plants may benefit from the temporary reprieve, as they grow larger and become more resilient to slug damage.