Plants and Animals

Pallifera fosteri Foster mantleslug

Key Characteristics

The foster mantleslug has no shell, is less than an inch in length, tan-colored with black blotches, and of a slim, cylindrical shape tapering to a point at the end. The short eye peduncles thicken at a rounded tip and the tentacles are very small.

Status and Rank

US Status: No Status/Not Listed
State Status: T - Threatened (legally protected)
Global Rank: G5 - Secure
State Rank: S1 - Critically imperiled


CountyNumber of OccurrencesYear Last Observed
Berrien 1 1950

Information is summarized from MNFI's database of rare species and community occurrences. Data may not reflect true distribution since much of the state has not been thoroughly surveyed.


The foster mantleslug is associated with upland and floodplain forest, usually beneath logs or organic litter (Hubricht 1985).

Natural Community Types

For each species, lists of natural communities were derived from review of the nearly 6,500 element occurrences in the MNFI database, in addition to herbarium label data for some taxa. In most cases, at least one specimen record exists for each listed natural community. For certain taxa, especially poorly collected or extirpated species of prairie and savanna habitats, natural community lists were derived from inferences from collection sites and habitat preferences in immediately adjacent states (particularly Indiana and Illinois). Natural communities are not listed for those species documented only from altered or ruderal habitats in Michigan, especially for taxa that occur in a variety of habitats outside of the state.

Natural communities are not listed in order of frequency of occurrence, but are rather derived from the full set of natural communities, organized by Ecological Group. In many cases, the general habitat descriptions should provide greater clarity and direction to the surveyor. In future versions of the Rare Species Explorer, we hope to incorporate natural community fidelity ranks for each taxon.

Management Recommendations

Identification and conservation of important habitat is an important first step toward management of the foster mantleslug and other terrestrial mollusks. Moist microhabitats with uncompacted soil and a rich organic litter layer are required by this and many other woodland species (Nekola 2003). Currently, the greatest threats to this group include habitat destruction through agricultural/residential development (Kay 1995), fragmentation and the loss of protective canopy cover, and vegetative ground cover/ organic litter loss through intensive recreational use (Applegarth 1999, Walden 1995). Snag retention may provide the foster mantleslug with important habitat as well as refuge during fire and drought (Applegarth 1999). Slugs rapidly absorb and bioaccumulate chemical pollutants and heavy metals (Berger and Dallinger 1993, Regoli et al. 2006), and high exposure to heavy metals has been found to prevent reproduction (Notten et al. 2006). Herbicide/insecticide treatments should be carried out with caution and affected populations monitored to evaluate impacts.

Active Period

Breeding from first week of May to fourth week of June

Survey Methods

Survey methods for slugs include both visual search for larger individuals and litter sampling for small (Pearce 2008).

Litter sampling

Survey Period: From first week of April to fourth week of October

Time of Day: Daytime

Visual surveys in suitable habitat

Survey Period: From first week of April to fourth week of October

Time of Day: Daytime
Precipitation: Just after rain


Survey References

  • Pearce, T.A. 2008. Land Snails of Limestone Communities and Update of Land Snail Distributions in Pennsylvania. Final Report for Agreement WRCP-04016. 51 pp.

Technical References

  • Applegarth, J.S. 1999. Management recommendations for terrestrial mollusk species, Megophix hemphilli, the Oregon Megomphix. Version 2.0. 39pp.
  • Baker, F.C. 1939. Fieldbook of Illinois Land Snails. Illinois Natural History Survey Manual 2, Urbana, Illinois. 166pp.
  • Berger, B. and R. Dallinger. 1993. Terrestrial snails as quantitative indicators of environmental metal pollution. Environmental Monitoring and Assessment 25(1):65-84.
  • Hubricht, L. 1985. The Distributions of Native Land Mollusks of the Eastern US. Field Museum of Natural History. Fieldiana: Zoology, No. 24.
  • Kay, E.A. 1995. Hug a slug, save a snail: A status report on molluscan diversity and a framework for conservation action. Pp. 53-79. In: E.A. Kay (ed). 1995. The Conservation Biology of Molluscs. IUCN, Gland, Switzerland.
  • Nekola, J.C. 2003. Large-scale terrestrial gastropod community composition patterns in the Great Lakes region of North America. Diversity and Distributions 9:55-71.
  • Regoli, F., S. Gorbi, D. Fattorini, S. Tedesco, A. Notti, N. Machella, R. Bocchetti, M. Benedetti, and F. Piva. 2006. Use of the Land Snail Helix aspersa as Sentinel Organism for Monitoring Ecotoxicologic Effects of Urban Pollution: An Integrated Approach. Environmental Health Perspectives 114(1):63-69.
  • Walden, H.W. 1995. Endangered species of land molluscs in Sweden and Madeira. In: The IUCN Species Survivial Commission, The Conservation Biology of Molluscs:19-24 (E. Alison Kay, Ed.) International Union for Conservation of Nature and Natural Resources, Gland, Switzerland.