Deroceras reticulatum
Species of gastropod
From Wikipedia, the free encyclopedia
Deroceras reticulatum, common names the grey field slug, grey garden slug, and milky slug, is a species of small air-breathing land slug, a terrestrial pulmonate gastropod mollusc in the family Agriolimacidae. This species is an important agricultural pest.
| Deroceras reticulatum | |
|---|---|
| |
| Adult Deroceras reticulatum | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| Order: | Stylommatophora |
| Family: | Agriolimacidae |
| Genus: | Deroceras |
| Species: | D. reticulatum |
| Binomial name | |
| Deroceras reticulatum (O. F. Müller, 1774)[3] | |
| Synonyms[4] | |
|
Agriolimax reticulatus (Müller, 1774) Limax reticulatus Müller, 1774 | |
Distribution
Deroceras reticulatum is native to Europe, North Africa and the Atlantic Islands.[4][5] It occurs widely in Europe, but is more rare and restricted to cultivated fields in the southeast, particularly in the Balkans, and is probably absent from Greece and the Bulgarian mountains.[4] In the north and central European lowlands, Great Britain, and Ireland, it is probably the most widely occurring slug.[4] In northern Scandinavia it is scarce, and is mainly found as a synanthrope.[4]
This species occurs in countries and islands including:
- Great Britain
- Ireland
- Austria
- Spain
- Bulgaria
- Czech Republic[6] – least concern (LC)[7]
- Netherlands[8]
- Poland
- Slovakia[6]
- Sweden
- Latvia
- Ukraine[9]
The species has been widely introduced as a synanthrope to many regions:
- North America,[4] in parts of Northern Michigan and Southern Michigan as well as Kentucky[10]
- Canada[citation needed]
- Colombia[11]
- Peru[4]
- Argentina – major slug pest in Buenos Aires province[12]
- Saint Helena[13]
- Tasmania[4]
- New Zealand[4]
- central Asia[4]
Description
a – atrium
p – penis
s – stimulator
mr – musculus retractor penis
gp – glandula penis
bc – bursa copulatrix
ov – oviductus.
As all other Deroceras it has a short keel at the back of the body. Deroceras reticulatum is very variable in colour, creamy or light coffee cream, rarely blackish spotted (slugs with spots may appear blackish).[4] Behind the mantle there is the dark spots form a reticulate pattern.[4] The skin is thick.[4] Mucus is colourless, on irritation milky white.[4] The slug cannot be distinguished from many other Deroceras species based only on its external appearance.[4]
This slug can be up to 40–60 mm long (preserved 25–30 mm).[4] The size varies according to the habitat.[4]
Reproductive system: Penis is fleshy and with a silky sheen, in the shape of an irregular sac, in fully mature specimens divided into 2 parts by a deep lateral constriction.[4] Penial gland has very variable shape, usually a few branches or a single long branch.[4] Stimulator is large, conical and narrow.[4] Retractor of the penis is inserted laterally.[4] Vas deferens opens into penis wall facing the external body side.[4] Rectal caecum is large.[4]
This slug can travel up to 40 feet (12.2 m) in one night.[14]
Ecology
Habitat
Deroceras reticulatum is almost exclusively restricted to cultivated areas, usually in open habitats, in meadows, near roadsides, in ruins, gardens and parks, not inside forests.[4] External appearance is very similar to Deroceras rodnae, Deroceras praecox and the internal anatomy is very similar to Deroceras turcicum, but those three species lives in natural habitats – in woods – and they co-occur with Deroceras reticulatum very rarely.[5] It shelters under stones and ground litter (It does not burrow into the soil).[4] It is active at night.[4]
Feeding habits
This species is omnivorous, feeding mainly on fresh leaves and fruits or seedings.[4] Deroceras reticulatum is a serious pest of agricultural crops, garden cultivations[4] and horticulture.[14] After several years with continuous moist weather conditions abundance can seriously increase.[4]
Life cycle
Life cycle covers a few months, usually two generations.[4] The main reproductive phase is in summer and autumn.[4] It lays hundreds of eggs which hatch during early summer.[14]
Maximum age is about a year.[4] Slugs die at the first frosts.[4] Usually only eggs hibernate, sometimes also juveniles.[4]
Predators
Various carabid beetles are predators of Deroceras reticlatum, including:
- the European garden beetle Carabus nemoralis, is a beneficial predator (from the human perspective) because it eats the young of this species and also their eggs.[14]
- Pterostichus melanarius[15]
- Pterostichus madidus[12]
- Nebria brevicollis[12]
- Scarites anthracinus eats eggs and slugs in Argentina.[12]
- Poecilus cupreus[15]
Parasites
The bacterium Moraxella osloensis is a mutualistic symbiont of the slug-parasitic nematode Phasmarhabditis hermaphrodita.[16] In nature, Phasmarhabditis hermaphrodita vectors Moraxella osloensis into the shell cavity of the slug host Deroceras reticulatum in which the bacteria multiply and kill the slug.[16]
Deroceras reticulatum can transfer Escherichia coli on its body surface.[17]
Parasites of Deroceras reticulatum include:
