Phragmatobia fuliginosa

Distinguished from similar tiger moths by the combination of dark reddish-brown forewings with blackish comma-shaped spot and bright carmine to rose-red hindwings with black marginal spots. The Ruby Tiger's hindwing coloration is more uniformly red and less heavily spotted than many related species. Subspecies borealis (northern Scotland and Eurasia) has more extensive black markings with red restricted; North American subspecies rubricosa similar to nominate form. May be confused with Phragmatobia placida (sometimes treated as separate species), which has more triangular forewings uniformly dark brown and hindwings pure light pink with black spots.

Forewings dark reddish-brown with dense scaling; a blackish comma-shaped spot at the apex of the cell, edged with carmine. Hindwings carmine to bright rose-red, more or less hyaline in the costal area, with more or less confluent black spots before the margin and at the apex of the cell. Underside strongly suffused with purple-pink. Thorax dark reddish-brown. Wingspan 35–45 mm. Eggs reddish-grey. Larva light or dark grey with black-brown head; entire body covered with foxy red hairs (more black-brown in some forms). Pupa black with abdomen marked with yellow in segmental incisions.

Moist open forest and meadow areas, mixed hardwood forests at low elevations, open meadows or prairies, and agricultural areas at low elevations. Common on low-growing plants, high-roads, railway embankments, and waste fields. Larval hiding places include ground-level vegetation; larvae sometimes found on field paths and roads on warm winter days.

Palearctic realm: most of Europe (widespread in Great Britain and Ireland, absent only from Shetland), North Africa, Russia, Central Asia, Tibet. Northern North America (as subspecies rubricosa). Subspecies: borealis in Scotland and northern Eurasia; melitensis in Malta; paghmani in Transcaucasia through Central Asia and western China; pulverulenta in eastern China, Mongolia, and southeastern Kazakhstan; rubricosa in North America; taurica in Near East from southern Turkey to Palestine.

Adults fly May to August depending on location. In southern England: bivoltine, with generations April–June and August–September. In northern Britain and northern regions: univoltine, with single generation in June. Overwintering stage: fully-grown larvae.

Polyphagous larvae feed on various plants including Rubus fruticosus (bramble), Prunus spinosa (blackthorn), Filipendula ulmaria (meadowsweet), Plantago lanceolata and P. major (plantains), Senecio jacobaea (ragwort) and other Senecio species, Salix repens, S. starkeana, S. phylicifolia (willows), Polygonum spp., Rumex crispus (curled dock), Potentilla erecta (tormentil), Rubus idaeus (raspberry), Trifolium spp. (clovers), Chamaenerion angustifolium (fireweed), Calluna vulgaris (heather), Vaccinium myrtillus (bilberry), V. uliginosum (bog bilberry), Andromeda polifolia (bog rosemary), and Taraxacum species (dandelions). Adults do not feed.

Spherical reddish-grey eggs deposited in batches. Hairy larvae feed through summer and autumn, overwinter fully-grown. Pupation in spring. In northern Britain typically single annual generation; in southern Britain usually two generations. Larvae show extreme cold tolerance—one individual observed embedded in ice for at least 14 days without apparent harm.

Adults occasionally active during day but more commonly recorded at light; late summer generation more attracted to light traps. Larvae bask in sunshine to raise body temperature above ambient. Speedy larvae often observed running across roads and paths, particularly on warm winter days when they leave hiding places. Male courtship involves pheromones derived from pyrrolizidine alkaloids obtained during larval feeding.

Larval herbivore in open habitats; contributes to nutrient cycling through consumption of diverse herbaceous plants. Adults serve as prey for birds, bats, and other insectivores. Male pheromone system based on sequestered plant alkaloids represents a tritrophic interaction.

Genome sequenced (629.4 Mb assembly, 28 chromosomal pseudomolecules, 13,338 protein-coding genes) as part of Darwin Tree of Life project. Occasionally encountered in gardens and agricultural areas. Not considered a pest species. Subject of ecological and physiological research due to larval cold tolerance and chemical ecology of pheromone production.

• Phragmatobia placidaOften treated as separate species; distinguished by more triangular, uniformly dark brown forewings and pure light pink hindwings with black spots
• Spilarctia luteumSimilar tiger moth with red hindwings, but forewing pattern differs and hindwing spotting more extensive
• Arctia cajaLarger garden tiger moth with more boldly patterned forewings and more heavily spotted hindwings

• moth
• Arctiinae
• tiger moth
• ruby tiger
• polyphagous
• cold tolerance
• genome sequenced
• pyrrolizidine alkaloids
• bivoltine
• univoltine
• Palearctic
• Nearctic

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• A New Cockroach in Town? | Bug Squad
• Fulgoridae | Beetles In The Bush
• Wolbachia in Cockroaches: A New Paradigm for Urban Pest Management?
• The genome sequence of the Ruby Tiger, Phragmatobia fuliginosa (Linnaeus, 1758).