Slug & Snails
by Daniel Frank, WVU Extension Service Entomology Specialist
Slugs and snails (also known as gastropods) belong to the animal group called mollusks. They feed on a variety of living plants, as well as decaying organic material. Slugs and snails are often considered a nuisance around the home and garden because they can cause extensive damage to a wide range of crops and ornamental plants—especially during mild, wet years.
DescriptionSlugs and snails are similar in form, except slugs do not have a snail’s protective spiral shell. They have soft, slimy, legless bodies with rasping mouthparts and two pairs of tentacles on the head. The upper, longer pair are optic tentacles with eyes located on the end. The lower, shorter tentacles are sensory organs used for feeling and tasting. These mollusks move using a muscular “foot” that encompasses the entire bottom of its body. The foot secretes a sticky mucus, which allows them to crawl upside down or on vertical surfaces. When the mucus dries it can leave a silvery, slimy trail that shows their path. Slugs and snails range in color from whitish-yellow to shades of brown, gray, or black. They can grow to lengths of .5 inch up to several inches.
DamageSlugs and snails often feed on young, succulent plant tissue. They scrape ragged, irregular holes in leaves and flowers, which can clip developing shoots. These pests can also damage fruits which ripen close to the ground, such as strawberries and tomatoes, by scraping small, shallow pits on their surface. However, most of the damage caused by slugs and snails occurs when they kill plants by feeding directly on seeds, or on seedlings that have germinated and emerged from the soil.
Douglas, M. R. and J. F. Tooker. 2012. Slug (Mollusca:Agriolimacidae, Arionidae) Ecology and Management in No-Till Field Crops, With an Emphasis on the mid-Atlantic Region. Journal of Integrated Pest Management. Vol. 3(1). Pp. C1-C9.
Thomas, A. K., R. J. McDonnell, T. D. Paine and J. D. Harwood. 2010. A Field Guide to the Slugs of Kentucky. University of Kentucky, Ag. Exp. Station Publication SR-103.