Chrysanthemum White Rust vs small tortoiseshell

Puccinia horiana compared with Aglais urticae

Key Differences

Chrysanthemum White Rust is Not Evaluated while small tortoiseshell is Near Threatened.

Taxonomic Classification

Rank	Chrysanthemum White Rust	small tortoiseshell
Kingdom	Fungi (Fungi)	Animalia (Animals)
Phylum	Basidiomycota (Club Fungi)	Arthropoda (Arthropods)
Class	Pucciniomycetes (Pucciniomycetes)	Insecta (Insects)
Order	Pucciniales (Pucciniales)	Lepidoptera (Butterflies & Moths)
Family	Pucciniaceae	Nymphalidae (Brush-footed Butterflies)
Genus	Puccinia	Aglais
Species	Puccinia horiana	Aglais urticae

Conservation Status

Chrysanthemum White Rust

NE — Not Evaluated

small tortoiseshell

NT — Near Threatened

Physical Characteristics

Attribute	Chrysanthemum White Rust	small tortoiseshell
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Chrysanthemum White Rust

Habitat

Native to Asia and Europe and South America, inhabiting ecosystems characteristic of the region.

Range

Widely distributed across Asia (Taiwan), Europe (12 countries), and South America (Brazil).

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.

Chrysanthemum White Rust

Chrysanthemum white rust is a disease caused by the fungal pathogen Puccinia horiana, a biotrophic rust fungus in the family Pucciniaceae. It is one of the most serious diseases affecting cultivated chrysanthemums globally and is classified as a quarantine pathogen in many countries. The disease was first described in Japan in the early twentieth century and has since spread to major chrysanthemum-producing regions worldwide through the international movement of infected plant material. Symptoms include pale green to yellow spots on the upper leaf surface corresponding to circular to angular white to pale pink pustules on the underside of the leaf, which produce masses of waxy, white teliospores. Unlike many rust fungi, Puccinia horiana has a simplified life cycle that does not require an alternate host, completing its development entirely on chrysanthemum. The fungus spreads readily via windborne spores, water splash, and contaminated cutting tools. Under cool, humid conditions with high relative humidity, infection can progress rapidly, causing extensive leaf damage and defoliation in severely affected plants. Strict phytosanitary measures including inspection of imported planting material, sanitation of growing facilities, and fungicide application are employed to manage the disease in commercial chrysanthemum production.

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.