Slugs Are Incredibly Interesting!

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Maybe the first thing that tips you off are mysterious, ragged holes ripping across fresh fruit or tearing through a green leaf. Or, maybe it’s a slick, shiny stripe of mucus across the plant surface that dries down to a matte, paint-like white streak. It’s no surprise slugs are among the most troublesome of garden pests, destroying healthy plants all while playing hard-to-get.

Slugs prefer moist, mild conditions, which are often found in our flower beds and vegetable gardens. If an area is bright or dry, slugs will shuffle off to wait for night or to find a covered, damp area.

As destructive as they are, slugs are also incredibly interesting! We think of a garden as the domain of insects, birds, and reptiles, but slugs and snails are relatives of the octopus, a mollusk. Further, the most destructive species of snails are from Europe rather than America. Slugs also have an interesting life cycle. They start life as one egg in a batch of 20-30 eggs that are resistant to drying out. Once they hatch, it can be over a year before a slug is fully matured. As they mature, they spend some time as a male before becoming hermaphrodites that can reproduce with any other slug it comes across. Once fully mature, they are females. When munching away at your garden, they prefer to eat an entire plant before moving on to the next. These critters are also able to live to the rich old age of six years—pretty impressive for a garden pest!

But the big question is: how do we actually control these rascals? If you want to go the natural, cultural route, consider setting traps. Place wooden boards on top of your soil to create a covered, cool, and damp area that will attract slugs. Every morning you should check your traps and kill any you find. Another chemical option is using copper in key areas of damage. Slugs will be repelled by the copper as they cannot cross it! For those of you looking for a one-and-done chemical spray, there are a few options, but you will need to reapply them. Look for products containing the active ingredient metaldehyde, carbaryl, or iron sulfate, and use according to the label. You may have to reapply every 5 to 7 days based on label recommendations and the damage you’ve observed.

For more information on slugs, contact your local extension office.

Selena McKoy is Horticulture Agent for North Carolina Cooperative Extension in Harnett County.