Deroceras invadens/panormitanum

Biological Name

Deroceras invadens Reise et al., 2011
(Until 2011 known as D. panormitanum)

Common Name

Brown field slug


A relatively small slug species, 20-35 mm body length, has a short keel at the back of the body. The pneumostome on the right side of the mantle is located in the posterior half of the mantle. The body colour is chocolate-brown to light grey. The skin is watery and almost transparent, on irritation it secretes clear mucus.

Other Similar Species

D. laeve, D. sturanyi, D. panormitanum s.s.

Biological Notes

Brown field slugs are fast moving slugs, mainly active on the surface but can also move through crevices of the soil. Brown field slugs have an annual life cycle but reproduces around the year.

Geographic Distribution

Its native range is Southwest Europe but it has spread worldwide and is established throughout Europe and North America, South America, South Africa, Australia and New Zealand.


Brown field slugs mainly inhabit disturbed sites, gardens, arable fields and greenhouses.

Crops at Risk

It affects plants with soft tissues like lettuce, asparagus, root crops and all kind of seedlings.

Damage Caused/Symptoms

In captivity, slugs are able to consume an amount of lettuce of their own body weight in two or three days.

Impact and Severity

The diet consists of dead and living plant material, green soft tissues of seedlings are likely to be damaged.

Prevention and Control

It is more common when pasture is a part of the crop rotation and can be reduced by tillage.

Natural Predators

The brown field slug is devoured by ground beetles and susceptible to the parasitic nematode Phasmarhabditis hermaphrodita, which is a biological control agent.