Deroceras reticulatum

Family

Agriolimacidae

Species

Deroceras reticulatum (O.F. Muller, 1774)

Common name

Grey fieldslug, Field slugSlug:
A snail that either does not possess a shell or has one that is very reduced (no definite coiling) or internal.
, Milky slug

Description

A mature grey fieldslug ranges in length from 35 to 50 mm. The stout body of this slugSlug:
A snail that either does not possess a shell or has one that is very reduced (no definite coiling) or internal.
may be cream-colored, greyish or has a slight pink-grey color. The mantleMantle:
A fleshy, membranous covering of the anterior portion of the body of a mollusc. It secretes the materials that form the shell.
has concentric striationsStriations:
Having a series of stripes, grooves or lines.
and usually covers more than one-third the length of the slugSlug:
A snail that either does not possess a shell or has one that is very reduced (no definite coiling) or internal.
. There are dark brown or grey flecks concentrated between the tuberclesTubercles:
An enlarged or raised region on the body of a slug. The shape of this structure is very variable. (See also tubercle)
. The tentaclesTentacles:
Sensory projections on the head end of a mollusc. There are generally two pairs; upper (posterior) and smaller, lower (anterior). The upper pair bears the eyes. In many snails the eyes are located at the tips of this structure; however, in Basommatophoran snail species, the eyes are located at the base of the tentacles.
are dark in color. The thin, clear, sticky mucus of this slugSlug:
A snail that either does not possess a shell or has one that is very reduced (no definite coiling) or internal.
often becomes a milky white when it is harassed. There is a short keelKeel:
Also known as the carina. This is a longitudinal ridge that runs dorsally along the apex of the tail of the animal.
at the tail end. The sole of the footFoot:
The muscular organ on the undersurface of the body of a mollusc upon which the animal rests or uses to crawl.
is tripartiteTripartite:
Having three distinct section/regions.
, whitish to grey-yellow in color with the medianMedian:
Along the central line or axis.
field grey. The pneumostomePneumostome:
This is the breathing hole on the right side of the mantle of molluscs. This allows air to pass through to the lung for gas exchange.(See also breathing pore).
(breathing pore) having a raised, pale border is located in the posteriorPosterior:
Directional term: the rear or tail end of an animal.
forth of the mantleMantle:
A fleshy, membranous covering of the anterior portion of the body of a mollusc. It secretes the materials that form the shell.
. This species can easily be confused with Deroceras agreste. In order to confirm the identity of this species, dissection and observation of the genitaliaGenitalia:
The reproductive structures of an animal. May refer to either male or female structure.
are required.

Deroceras agreste. The penis (p) of this species is broad with only a single appendix.

Deroceras caucasicum: The penis is broad and has two appendixes at the tip with the vas deferens emerges between them. The posteriorPosterior:
Directional term: the rear or tail end of an animal.
edge of the penis is pigmented (dark-colored) and there is a hard "clam-shaped" shell-like plate inside the penis.

Deroceras laeve: The penis of this species is long, narrow and mostly twisted, with only a single appendix. It should be noted that a penis may be absent in some specimens.

Deroceras panormitanum: The penis in the species is broad and markedly bilobed with 4-6 appendixes.

Deroceras reticulatum: The penis (p) in the species is broad with only a single, irregularly branched appendix.

Native range

Western Europe

Distribution

North America:

• U.S.: Alabama, California, Colorado, Hawaii, Illinois, Kentucky, Michigan, Ohio, Oklahoma, Utah, Washington, Wisconsin, Wyoming
• Canada: Newfoundland, Quebec, Ontario, British Columbia

Asia: Sri Lanka

Australasia: New Zealand

Europe

Ecology

This slugSlug:
A snail that either does not possess a shell or has one that is very reduced (no definite coiling) or internal.
prefers modified habitats, such as garden, greenhouses, roadsides and fields. The diet of D. reticulatum is primarilly constituted of living plant material but this slugSlug:
A snail that either does not possess a shell or has one that is very reduced (no definite coiling) or internal.
is an omnivore and may consume mushrooms, dead slugs, earthworms and other animal matter. This species is especially destructive to seedlings and succulent plants. In northern Europe and North America this species damages grains, clover and vegetable crops. This slugSlug:
A snail that either does not possess a shell or has one that is very reduced (no definite coiling) or internal.
has the potential to detect predatory carabid beetles through the use of olfactoryOlfactory:
Of or relating to the sense of smell.
cues. When attacked, the slugSlug:
A snail that either does not possess a shell or has one that is very reduced (no definite coiling) or internal.
lashes its tail, secretes copious amounts of mucus and flees its attacker. The slugSlug:
A snail that either does not possess a shell or has one that is very reduced (no definite coiling) or internal.
may also amputate the tip of its tail to evade predation. Reproduction is by cross-fertilization and occurs year round under favorable conditions. Mating occurs mainly at night and approximately 60-75 eggs (4 mm each) are produced per clutch totaling approximately 700 eggs per year per specimen. The animal’s lifespan is generally one to two years.

Synonyms

• Limax agrestis Linnaeus, 1758. Syst. Nat. 1: 1082 (part).
• Limax reticulatus Muller, 1774 Verm. Terr. Et fluv. Hist., 2:10 (gardens of Rosenburg and Fridricksdal).
• Limax canariensis d'Orbigny, 1839. Hist. NAt. Iles Canaries (Webb and Berthelot) 2(2): 47.
• Limax tunicata Gould, 1841, Invert. of Mass. p. 3 (Massachusetts).
• Krynickillus minutus Kalenickzenko, 1851. Bull. Soc. Imp. Nat. Moscou 24: 224.
• Limax agrestis Leidy, 1851, in Binney, Terr. Moll., 1: 250, pl. 2, figs. 7-9 (anatomy); Binney, 1851, Terr. Mol. 2: 36, pl. 64, fig. 2.; W.G. Binney, 1878. Terr. Moll. 5:146. Not Limax agrestis Linnaeus, 1758, Syst. Nat. (10) p. 652, as restricted by Luther.
• Limax molestus Hutton, 1879. Trans. N.Z. Inst. 11: 331 (new synonymy).
• Krynickillus niciensis (Boettger) Nevill, 1880. Proc. Zool. Soc. Lond.: 103.
• Agriolimax agrestis L. of most authors in the last century; Cockerell , 1891, Nautilus, 5: 70 (named color-varieties); 11: 15, fig. 1 (monstrosity); 7:21 (in Jamaica)
• Agriolimax reticulatus Muller, Luther, 1915 Actes fauna et flora Fennica, 40, No. 2.; Ingram, 1943, Nautilus, 55:67.

References

Anderson 2005Anderson 2005:
Anderson, R. 2005. An annotated list of the non-marine Mollusca of Britain and Ireland. Journal of Conchology 38: 607-637.; Barker 1979Barker 1979:
Barker, G.M. 1979. The introduced slugs of New Zealand (Gastropoda: Pulmonata). New Zealand Journal of Zoology. 6: 411-437.; Branson 1959Branson 1959:
Branson, B.A. 1959. Notes on Oklahoma slugs, with additions to the previously known fauna. The Southwestern Naturalist 4: 143-147.; Branson 1962Branson 1962:
Branson, B.A. 1962. The slugs (Gastropoda: Pulmonata) of Oklahoma and Kansas with New Records. Transactions of the Kansas Academy of Science 65(2): 110-119.; Branson 1980Branson 1980:
Branson, B. A. 1980. The recent Gastropoda of Oklahoma, part VIII. The slug families Limacidae, Arionidae, Veronicellidae and Philomycidae. Proceedings of the Oklahoma Academy of Science 60: 29-35.; Carrick 1942Carrick 1942:
Carrick, R. 1942. The grey field slug Agriolimax agrestis L., and its environment. Annals of Applied Biology 29(1): 43-55.; Cowie 1997Cowie 1997:
Cowie, R.H. 1997. Catalog and bibliography of the nonindigenous nonmarine snails and slugs of the Hawaiian Islands. Bishop Museum Occasional Papers. 50.; Cowie et al. 2009; Forsyth 2004Forsyth 2004:
Forsyth, R.G. 2004. Royal BC museum handbook: land snails of British Columbia. Victoria, Canada: Royal BC Museum. pp. 1-188.; Horsák et al. 2004Horsák et al. 2004:
Horsák, M., L. Dvorák and L. Juricková. 2004. Greenhouse gastropods of the Czech Republic: current stage of research. Malacological Newsletter 22: 141-147.; Hutchinson and Heike 2007; Kerney et al. 1979Kerney et al. 1979:
Kerney, M.P., R.A.D. Cameron and G. Riley. 1979. A field guide to the land snails of Britain and North-west Europe. Collins, London. pp. 288.; Naggs et al. 2003Naggs et al. 2003:
Naggs, F., D.C. Raheem, P.B. Mordan, B. Grimm, K.B. Ranawana and N.P.S. Kumburegama. 2003. Ancient relicts and contemporary exotics: faunal change and survivorship in Sri Lanka’s snail fauna. Slug and Snails: Agricultural, Veterinary and Environmental Perspectives. BCPC Symposium Proceedings 80: 103-108.; Pilsbry 1939Pilsbry 1939:
Pilsbry, H. A. 1939. Land Mollusca of North America north of Mexico vol. I part 1. Academy of Natural Sciences, Philadelphia. pp. 1-574.; Thomas et al. 2010Thomas et al. 2010:
Thomas, A.K., R.J. McDonnell, T.D. Paine and J.D. Hardwood. 2010. A field guide to the slugs of Kentucky. Agricultural Experiment Station. University of Kentucky, College of Agriculture, SR-103.; Wiktor 2000