Habitat

Deroceras laeve has high ecological tolerance, but needs permanently wet habitats.^[3] It is usually found in lowlands and very humid habitats, swamps, riversides, wetlands, especially alder and oak woods, marshlands and degraded areas, also greenhouses, often near water under wood or detritus.^[3] It tolerates subpolar and tropical temperatures.^[3] Newly created habitats are often colonized after a few years.^[3] In Switzerland in up to 1800 m altitude, but usually below 1000 m, in Bulgaria in up to 2500 m.^[3]

Deroceras laeve can be a serious pest in greenhouses.^[3] On the other hand, the species is threatened by continuous elimination of wet habitats by drainage, construction projects and road construction.^[3]

It is the only land gastropod that goes deliberately into the water and can survive for days submerged.^[3] Because of this unusual behavior, the species can be dispersed by flowing water.^[3]

Feeding habits

Deroceras laeve is omnivorous and capable of eating eggs and small insects, but tends to prefer plant matter, either alive or dead.^[3][18][12]

Life cycle

The eggs of this species can also survive when submerged; juveniles can hatch underwater and then climb to the surface.^[3]

The life cycle is extremely short, and can take place within less than a month.^[3] This species can have up to 5 generations in a year,^[3] with several generations alive at the same time.^[3] Frequently there are forms with a reduced penis, which reproduce by self-fertilisation.^[3] The maximum age of this slug is not more than 1 year.^[3]

Parasites

Parasites of Deroceras laeve include:

• Parelaphostrongylus tenuis^[19]