Gardeners get ready for invasion of the sex-mad, sleepless slugs
Irish gardens are set to be "devastated" by an unusually high number of slugs this summer, as a mild winter is expected to result in a massive increase in the gastropod population.
"Sleepless slugs" have been forgoing winter hibernation because of the warmer weather, experts have said, meaning they have been breeding throughout the year rather than in just the summer. The population of natural predators, such as hedgehogs, has also been falling.
The fears were highlighted by UK insect charity BugLife, which said that the slugs were breeding faster than they could be controlled and could be very destructive to horticulture in the coming months. The average Irish garden contains as many as 20,000 slugs - with the gastropods laying as many as 200 eggs per cubic metre - but that number could be 10pc higher in our gardens this summer.
"When the weather warms to five degrees or more, the existing relatively high population of slugs will begin to breed more rapidly, with peak activity at about 10 degrees," Guy Barter, chief horticulturalist at the Royal Horticultural Society (RHS), said.
"If the weather is reasonably moist, numbers might peak, which may lead to severe damage, but a dry spring and summer will inhibit their activity. However, this spring the risk is high that we will face serious slug infestations."
The effects of an unusually high slug population are already being felt. Barter said the RHS was currently observing damage to daffodils because of rampant slugs eating away at the plants. In addition, he said emerging hostas were in need of protection and seedlings were "very much at risk" from slugs.
Dr Ian Bedford, head of entomology at the John Innes Centre, warned that the slug explosion would likely lead to more invasive Spanish Slugs, which can reach 15cm in length. This creature, which is susceptible to cold weather, breeds more prolifically than native slugs and can completely take over areas, driving out other species due to their population density.
The RHS advised concerned gardeners to apply slug control nematodes as soon as the weather warms. "In the meantime, weeding, tidying up and lightly tilling the soil will expose molluscs to weather and predators," Barter said.