Alder Spittlebug vs Chlorine Dust Lichen

Aphrophora alni compared with Chrysothrix chlorina

Key Differences

Alder Spittlebug is Least Concern while Chlorine Dust Lichen is Extinct.

Taxonomic Classification

Rank	Alder Spittlebug	Chlorine Dust Lichen
Kingdom	Animalia (Animals)	Fungi (Fungi)
Phylum	Arthropoda (Arthropods)	Ascomycota (Sac Fungi)
Class	Insecta (Insects)	Arthoniomycetes (Arthoniomycetes)
Order	Hemiptera (Hemiptera)	Arthoniales (Arthoniales)
Family	Aphrophoridae	Chrysotrichaceae
Genus	Aphrophora	Chrysothrix
Species	Aphrophora alni	Chrysothrix chlorina

Conservation Status

Alder Spittlebug

LC — Least Concern

Chlorine Dust Lichen

EX — Extinct

Physical Characteristics

Attribute	Alder Spittlebug	Chlorine Dust Lichen
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Alder Spittlebug

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Found across Europe (5 countries) and North America (United States).

Chlorine Dust Lichen

Habitat

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

Range

Widely distributed across Europe (4 countries), North America (United States), and South America (Brazil, Colombia).

Alder Spittlebug

The Alder Spittlebug (Aphrophora alni) is a species in the genus Aphrophora. It is currently classified as Least Concern on the IUCN Red List. Typically found in virtually all terrestrial and freshwater habitats.

Chlorine Dust Lichen

The Chlorine Dust Lichen (Chrysothrix chlorina) is a crustose lichen in the family Chrysotrichaceae, historically known from calcareous and siliceous rock surfaces and bark in parts of Europe, including the United Kingdom. It belongs to the genus Chrysothrix, a group of powdery, granular lichens that form bright yellow to greenish-yellow leprose thalli — lacking the organised cortex layers of most lichens — composed largely of granular soredia. Chrysothrix species produce unique secondary metabolites including rhizocarpic acid, which contributes to their intense yellow colouration and may serve as protection against grazing invertebrates. The Chlorine Dust Lichen takes its name from the sharp, bleach-like or chlorine odour emitted when the thallus is moistened — a distinctive diagnostic feature. The IUCN has assessed this species as Extinct in Great Britain, where it was historically recorded from ancient woodland and shaded rock sites but has not been confirmed in recent decades. Its apparent extinction in parts of its former range is attributed primarily to severe air quality degradation during the industrial era, as many crustose lichens are highly sensitive to sulphur dioxide and other atmospheric pollutants. It may persist in small areas of cleaner air, and improved air quality since deindustrialisation offers some hope for natural recolonisation.