Winding Mantleslug

While in the Smoky Mountains this summer I came across this mottled looking slug clinging to the side of a deciduous tree in the mosses growing there. It was about 2 or 3 inches in length and was different from the slugs I typically see at home. I posted a pictured on Facebook and Marla Coppolino from Cornell University, who happens to be a slug and snail enthusiast and expert ID'd it quickly as Philomycus flexuolaris, the winding mantleslug. 


Marla explained to me that these slugs are beneficial to the environment, unlike many species of invasive slugs that show up in our green houses and gardens and feed on your prized vegetables or flowers, these slugs inhabit hardwood forests within the Appalachian Mountains. Winding Mantleslugs break down organic matter, like fallen leaves, lichens, and mushrooms in the forests where they live which enriches the soil, providing necessary nutrients for plant growth. They are often found feeding at night during the rainy season, and it is not uncommon to find several specimens on a single tree with intertwining slim trails leading them to food sources.

These slugs can vary in color from tan to gray and typically have a mottled or marbled appearance with darker brown blotches. When alarmed they will produce a yellowish mucus that is distasteful to potential predators. This slim also leaves behind a specific scent that helps them find potential mates, in addition it keeps their bodies moist and lubricated so they do not desiccate (dry out). Slugs and snails are so slimy with mucus they can even crawl across the edge of a razor blade with no fear of harm!! 

Because slugs are moist environment inhabitants, they cannot tolerate arid or hot temperatures. During the driest, and hottest parts of the year these slugs find sheltered areas to wait out the inhospitable climate in a form of hibernation called aestivation. They will be found under the bark of trees, within rotting logs and stumps and under leaf litter on the forest floor. When the weather is more to their liking they will become active again. 

While slugs and snails may not be everyone's cup-o-tea, I find them fascinating and interesting creatures and never tire of finding them.