orange-banded arion

LC - Least Concern

NNA - Not applicable

not listed

Orange-banded arion is a common, exotic, terrestrial, roundback slug. It is native to northern Europe and was introduced into North America during the colonial era. It has slowly spread from New England north to Quebec, south to North Carolina, and west to Minnesota. It is listed as invasive in Wisconsin, where it has been present since 1948, but not in Minnesota and not nationally. It is found in ground litter and on herbaceous plants in forests, wet meadows adjacent to streams, and open and cultivated areas, including old fields and gardens.

The adult is 1¼″ to 2″ long and grayish to yellowish-brown above. It has no shell. The body is long and slender when extended, short and bell-shaped in cross section when contracted. It is covered with rows of pale bumps (tubercles), giving it a granular appearance. The row of tubercles in the middle (middorsal) are slightly enlarged, giving the false impression of a keel, but this species is not keeled. There are two lateral, dark, blurry, longitudinal stripes. The stripes are broken at the edge of the back plate (mantle). The area just below each stripe is yellowish, and the area below that, near the foot fringe, is whitish. The sole is grayish-white. The mucus it emits is colorless. The head and tentacles are black.

Juveniles have more well-defined lateral stripes and the middorsal tubercles give the appearance of a more prominent dorsal ridge.

Total length: 1¼″ to 2″

Forests, wet meadows adjacent to streams, and open and cultivated areas, including old fields and gardens

Active mostly at night.

Decaying leaves that lack chlorophyll, earthworms, and small arthropods.

Sources

24, 29, 30.

Invasive Species of Aquatic Plants and Wild Animals in Minnesota Annual Report 2011 for the year ending December 31.

Native to northern Europe. Introduced.

Common

Until recently, this was considered a species complex that included Arion silvaticus, A. circumscriptus and A. fasciatus. The three species were differentiated by color and by their genitalia. It was later determined that the color was influenced by diet and the genital differences could not be confirmed.

Location: Albany, NY

Location: Woodbury, Minnesota

Location: Woodbury, Minnesota