Common Tarcrust vs small tortoiseshell

Diatrype stigma compared with Aglais urticae

Key Differences

Common Tarcrust is Not Evaluated while small tortoiseshell is Near Threatened.

Taxonomic Classification

Rank	Common Tarcrust	small tortoiseshell
Kingdom	Fungi (Fungi)	Animalia (Animals)
Phylum	Ascomycota (Sac Fungi)	Arthropoda (Arthropods)
Class	Sordariomycetes (Sordariomycetes)	Insecta (Insects)
Order	Xylariales (Xylariales)	Lepidoptera (Butterflies & Moths)
Family	Diatrypaceae	Nymphalidae (Brush-footed Butterflies)
Genus	Diatrype	Aglais
Species	Diatrype stigma	Aglais urticae

Conservation Status

Common Tarcrust

NE — Not Evaluated

small tortoiseshell

NT — Near Threatened

Physical Characteristics

Attribute	Common Tarcrust	small tortoiseshell
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Common Tarcrust

Habitat

Native to Europe, inhabiting ecosystems characteristic of the region.

Range

Distributed across Belgium, Denmark, Norway, Portugal, and Sweden.

small tortoiseshell

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Found across Europe (41 countries). Listed as Near Threatened, this species requires ongoing monitoring to prevent population decline.

Common Tarcrust

<em>Diatrype stigma</em>, the common tarcrust, is a saprotrophic fungus in the family Diatrypaceae, found across Belgium, Denmark, Norway, Portugal, and Sweden, as well as more broadly in Europe and temperate regions globally. It grows as a crust-like, charcoal-black stromata on the dead bark and branches of deciduous hardwoods, particularly hazel, beech, and alder. The fruiting bodies are typically flat to slightly raised, dark gray to black patches that contain numerous embedded perithecia in which ascospores are produced. This fungus plays an important ecological role as a decomposer, breaking down dead woody material and recycling nutrients in forest ecosystems. It is Not Evaluated on the IUCN Red List; given its broad distribution on common substrates, it is generally considered widespread. The species reproduces via wind-dispersed ascospores released from the perithecia. Diet, as a saprotrophic organism, consists of dead organic woody matter. Biological traits such as colony growth rates, spore output, and longevity remain poorly documented in standardized quantitative assessments.

small tortoiseshell

small tortoiseshell (Aglais urticae) is classified as Near Threatened (NT) on the IUCN Red List. Close to qualifying as threatened, with populations that may become vulnerable without conservation action.