Slugs
Discover everything you need to know about slugs in our guide below.
Gastropoda
What are Slugs?
Slugs are mollusks and members of the class Gastropoda. While some slugs have a hard shell, others are shell-less – with soft, slimy bodies. In fact, slugs are related to clams and oysters. While some slugs live in marine environments, others are land pests that destroy gardens and thrive in moist environments.
Depending on the species, slugs can vary from 2” to 4” long. Most slugs look like fat, slimy worms with two distinct eyestalks that they use as taste buds and feelers. They tend to be gray or mottled in color.
While there are about 40,000 different species of gastropods worldwide, the most common slugs in the US include the Leopard Slug, the Great Gray Garden Slug, and the Tiger Slug.
The Behavior, Diet, and Habits of Slugs
Since slugs have moist, slimy bodies, they require humid environments, like the coastal areas of the eastern and western United States, to thrive.
In the wild, they live on the forest floor under rotting organic matter like leaves. In urban areas, they love to live in gardens, hiding under vegetables and ornamental plants and enjoying the regular watering the garden receives.
When it comes to diet, slugs are omnivores. They consume plant leaves, roots, stems, decaying organic matter and debris, fungi, and earthworms when possible.
Slugs are hermaphroditic, meaning that every slug has both male and female reproductive organs and that any slug can lay and self-fertilize eggs. That makes slug populations relatively challenging to control since infestations can self-generate.
Once laid, slug eggs take two weeks-1 month to hatch in temperate environments, or up to 5 months to hatch if the eggs are laid during the winter.
What Damage do Slugs Cause?
Slugs are widespread garden pests. While a few slugs in your garden aren’t a problem, large slug populations will over-feed on your garden plants, weakening the plant to the point of killing it. In orchards and commercial settings, slugs can also reduce the harvest of veggies and fruits.
Slugs use their mouthparts, called a radula, to rasp, chew, and destroy plant tissue. These pests are especially fond of the leaves of tender, young plant seedlings. They will also eat ripening fruits and vegetables.
One of the first signs of slug infestations is usually irregularly shaped, rough-edged holes in leaves, flowers, stems, bulbs, and tubers. In temperate climates, slugs will damage plants all year, although seedings are usually most at risk, and spring is when most slug predation occurs.
While slugs don’t carry the diseases associated with other pests, like rats, mice, or ground squirrels, they can carry a disease known as rat lungworms (Angiostrongylus cantonensis) and transmit it to humans. The disease is a parasitic nematode that resides in rodents but uses mollusks as hosts.
People can contract the disease if they accidentally eat a slug that is infected with lungworm larvae or if they consume unwashed spinach, kale, or other leafy greens that have been contaminated by the slime from infected slugs or snails.
Last but not least, high populations of slugs can lead to other problematic pest infestations since rats, beetles, and birds love to eat slugs.
How to Get Rid of Slugs
If slugs are destroying your garden, it’s essential to get rid of them quickly before they attract other pests or ruin your plants.
Here are a few quick tips:
- Keep grass trimmed, especially around vegetable gardens. This limits moisture and shade and reduces slug hiding places.
- Remove debris in your yard. This includes overturned pots, leaf piles, and wood, all ideal hiding places for slugs.
- Prune your garden regularly to keep dead and dying leaves out of the space. This improves airflow and reduces the shady hiding spots slugs rely on.
- Avoid over-watering gardens.
- Bury a Tupperware container about 6” deep into your garden’s soil, leaving a small lip above the soil. Fill the container ¾ full of beer. The slugs will be attracted to the beer, which will drown them when they enter it.
- Use chemical control methods containing metaldehyde or methiocarb to kill slugs.
In addition to the DIY options listed above, you can use slug pellets or store-bought baits to eliminate slugs in your garden.
Alternatively, contact a pest control company for professional assistance in removing the slimy visitors.
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FAQs
Small slug populations are good for your garden. Because slugs consume decaying organic matter, they break down garden debris and turn them into fertilizer, which enhances your soil and makes your garden more productive. Too many slugs, however, can destroy your ornamental plants, fruits, and veggies
Slugs are attracted to gardens that offer shelter, food, and the ideal habitat. They like to eat soft plant material, like new transplants or ripe strawberries and prefer crowded, shady gardens with plenty of hiding places.
Yes, as long as you wash it first. Small amounts of slug damage are almost impossible to avoid if you have a garden. Fortunately, you don’t have to throw out lightly slug-damaged produce. To avoid slug-transmitted diseases, though, be sure to wash all garden produce before you eat it. Additionally, we recommend cutting out visibly slug-damaged parts of the produce.