Chocolate arion vs clouded magpie

Arion rufus compared with Abraxas sylvata

Taxonomic Classification

Rank	Chocolate arion	clouded magpie
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Mollusca (Mollusks)	Arthropoda (Arthropods)
Class	Gastropoda (Gastropoda)	Insecta (Insects)
Order	Stylommatophora (Stylommatophora)	Lepidoptera (Butterflies & Moths)
Family	Arionidae	Geometridae
Genus	Arion	Abraxas
Species	Arion rufus	Abraxas sylvata

Evolutionary Relationship

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

Conservation Status

Chocolate arion

VU — Vulnerable

clouded magpie

VU — Vulnerable

Physical Characteristics

Attribute	Chocolate arion	clouded magpie
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 magpie

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Belgium, Denmark, Norway, and Sweden. Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

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 magpie

The clouded magpie (Abraxas sylvata) is a geometrid moth in the family Geometridae found across temperate Europe, extending eastward through Russia to Japan. The adult wingspan measures approximately 32–42 mm, with white wings bearing a distinctive pattern of yellow-orange and dark grey to black spots and patches arranged in rows across the forewing and hindwing, creating a striking patterned appearance resembling the magpie coloring of the related magpie moth Abraxas grossulariata, but with a more yellowish, muted tone and less black — hence 'clouded.' Adults fly in one generation from June to July, resting on leaf surfaces and attending woodland flowers for nectar. The larvae feed on wych elm (Ulmus glabra) and occasionally other Ulmus species in mature deciduous woodland and woodland edges. The clouded magpie has become less common in parts of its European range due to the widespread loss of mature elms from Dutch elm disease, which devastated European elm populations from the 1970s onward. Conservation of this species requires the protection of surviving mature elm trees and management of regrowth elms in woodland ecosystems.

Shared Countries

Both species can be found in 4 countries:

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