Limacus flavus Linnaeus, 1758
L. flavus is a synanthropic slug that was probably native to the Mediterranean region and has been introduced worldwide.
Regularly returns, or "homes," to shelter (Cook 1979). Active at night (Quick 1960).
External: Yellowish to orange-pink body, with gray-green mottling; light blue-gray tentacles; short keel; yellow-white sole; yellow body mucus, clear sole mucus (Herbert 1997; Kerney & Cameron 1979).
Internal: 9 x 6 mm internal shell; long, twisting penis 1/6 body length; vas deferens attaches next to penial retractor; a crinkled fold down entire internal length of penis; oviduct widens at junction with atrium; spermatheca connects to oviduct; long rectal caecum (Quick 1960; Wiktor et al. 2000).
Similar to Limacus pseudoflavus but L. pseudoflavus is grayer and has darker markings, coarser tubercles, gray tentacles (Kerney & Cameron 1979). Resembles Limacus maculatus but lighter in color and spermatheca does not connect to penis (Wiktor et al. 2000).
Eggs: 6 x 4 mm, light amber, lemon-shaped (Quick 1960).
Juveniles: 10-13 mm long, light green-yellow with blue tentacles at hatching; yellow spots appear later (Quick 1960).
75-100 mm long extended (Herbert 1997).
Occurs in Europe north to S Norway, south to N Africa, and east to Syria in Asia Minor (Quick 1960). Probably native to Mediterranean countries originally (Kerney & Cameron 1979).
Non-native in: Japan (Azuma 1982), Russia (Sverlova 2006; in Sysoev & Schileyko 2009), China, (Wiktor et al. 2000), South Africa, N and S America, Madagascar, Australasia (Herbert 1997).
Occupies disturbed habitats, gardens, waste piles, and buildings; takes shelter under logs, discarded waste (Herbert 2010).
In their home range, occupy Mediterranean forests (Wiktor et al. 2000; Heller 2009).
In Britain, L. flavus mates in late summer to February and lays eggs in September and February (Quick 1960).
Dead plants, lichen, fungi, domestic waste (Herbert 2010), live plant material (esp. roots and fruit) (Wiktor et al. 2000).