Chocolate arion vs clouded-bordered brindle

Arion rufus compared with Apamea crenata

Key Differences

• Chocolate arion is Vulnerable while clouded-bordered brindle is Least Concern.

Taxonomic Classification

Rank	Chocolate arion	clouded-bordered brindle
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Mollusca (Mollusks)	Arthropoda (Arthropods)
Class	Gastropoda (Gastropoda)	Insecta (Insects)
Order	Stylommatophora (Stylommatophora)	Lepidoptera (Butterflies & Moths)
Family	Arionidae	Noctuidae
Genus	Arion	Apamea
Species	Arion rufus	Apamea crenata

Evolutionary Relationship

Chocolate arion and clouded-bordered brindle share a common ancestor at the Kingdom level: Animalia. (Animals)

Conservation Status

Chocolate arion

VU — Vulnerable

clouded-bordered brindle

LC — Least Concern

Physical Characteristics

Attribute	Chocolate arion	clouded-bordered brindle
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Chocolate arion

Habitat

Inhabits temperate broadleaf and mixed forests and Mediterranean forests and woodlands within the Palearctic biogeographic realm. Populations are also found in montane and highland environments at higher elevations.

Range

Found across Europe (7 countries) and North America (United States). Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

clouded-bordered brindle

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Found across Asia (Taiwan) and Europe (5 countries).

Chocolate arion

The Chocolate Arion (Arion rufus), also known as the Large Red Slug or Chocolate Slug, is one of Europe's largest terrestrial slugs, with adults reaching up to 15 centimetres in length. It belongs to the family Arionidae within the phylum Mollusca, and despite its common name, adults display highly variable colouration ranging from reddish-orange to dark brown and nearly black — only certain colour morphs exhibit the chocolate-brown hue that partly inspired the name. Arion rufus is native to western and central Europe, where it inhabits woodland, hedgerows, gardens, agricultural land, and other moist habitats. It is also established as an introduced species in parts of North America. Like other arionid slugs, it is primarily a detritivore and herbivore, consuming dead plant material, fungi, living plant tissue, and sometimes carrion. It shelters under logs, stones, and leaf litter during dry or cold conditions, becoming active — particularly at night — during warm, moist weather. Chocolate arion can cause significant damage to gardens and crops. Reproduction is hermaphroditic; slugs exchange sperm and lay batches of translucent eggs in soil or under debris. The IUCN classifies this species as Vulnerable, reflecting pressures on native European populations from habitat change and, possibly, competition and hybridisation with related Arion species.

clouded-bordered brindle

The clouded bordered brindle (Apamea crenata) is a noctuid moth in the family Noctuidae found across temperate Europe and across northern Asia to Japan. The adult wingspan measures approximately 38–45 mm, with intricately patterned grey-brown and buff forewings bearing subtle cross-lines, a scalloped (crenate) outer margin giving the species its name, and distinctive reniform and orbicular markings characteristic of the Apamea genus. Adults fly in one generation from May to July, visiting flowers for nectar at night. The larvae feed internally within the stems and roots of grasses, particularly Brachypodium and other coarse grass species in woodland rides, woodland margins, and rough grassland habitats. Overwintering occurs as a larva within plant stems. Like many grass-feeding noctuids, the clouded bordered brindle requires structural diversity in its grassland and woodland edge habitats, with areas of tall, tussocky grasses providing both larval foodplants and adult shelter. Population trends in parts of its European range reflect changes in land management affecting coarse grassland and woodland ride quality.

Shared Countries

Both species can be found in 4 countries:

🇧🇪 Belgium 🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden