Cola-Nut Gall vs Common Metad

Andricus lignicolus compared with Millardia meltada

Key Differences

• Cola-Nut Gall is Not Evaluated while Common Metad is Least Concern.

Taxonomic Classification

Rank	Cola-Nut Gall	Common Metad
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Arthropoda (Arthropods)	Chordata (Chordates)
Class	Insecta (Insects)	Mammalia (Mammals)
Order	Hymenoptera (Ants, Bees & Wasps)	Rodentia (Rodents)
Family	Cynipidae	Muridae (Mice & Rats)
Genus	Andricus	Millardia
Species	Andricus lignicolus	Millardia meltada

Evolutionary Relationship

Cola-Nut Gall and Common Metad share a common ancestor at the Kingdom level: Animalia. (Animals)

Conservation Status

Cola-Nut Gall

NE — Not Evaluated

Common Metad

LC — Least Concern

Physical Characteristics

Attribute	Cola-Nut Gall	Common Metad
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Cola-Nut Gall

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Found across Europe (6 countries).

Common Metad

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Cola-Nut Gall

<em>Andricus lignicolus</em> is a gall wasp in the family Cynipidae. The name "Cola-Nut Gall" refers to the gall structure this species induces on oak trees, rather than a conventional common name for the organism itself. <em>Andricus lignicolus</em> has been recorded across parts of western and northern Europe, including Belgium, Denmark, France, Ireland, and the Netherlands. The species occupies a broad range of terrestrial and freshwater habitats within its range, reflecting the wide distribution of its host oak trees. Gall wasps in the genus <em>Andricus</em> have complex life cycles often involving alternating sexual and asexual generations, with different generations producing distinct gall morphologies on the same or different oak species. The species has not been assessed under the IUCN Red List. Diet data and specific biological measurements for <em>Andricus lignicolus</em> are not documented in available sources. Biological traits of this species remain poorly documented in the scientific literature. Its ecological role is tied to its host plants, and like other cynipid gall wasps, it likely hosts a variety of inquiline and parasitoid insects within its galls.

Common Metad

The Common Metad (<em>Millardia meltada</em>) is a rodent belonging to the genus <em>Millardia</em> within the family Muridae. As a member of the Old World rats and mice, this species is typically found in diverse terrestrial and aquatic ecosystems across its range. The Common Metad is classified as Least Concern on the IUCN Red List, indicating that its populations are currently stable and not facing immediate extinction risk. Detailed biological traits such as body length, weight, and lifespan have not been widely documented for this species in available records. Its taxonomy places it within the order Rodentia, which encompasses a broad array of gnawing mammals adapted to a wide variety of ecological niches. While specific dietary habits are not well characterized in the available data, members of the genus <em>Millardia</em> are generally understood to be omnivorous, feeding on plant material and invertebrates typical of their habitat. Ongoing monitoring is important for ensuring this species maintains its current conservation standing.