Euproctis chrysorrhoea

Adults identified by white wings and conspicuous brown hair tuft at abdomen tip. Larvae distinguished from similar lymantriine moths by paired dorsal tufts of urticating hairs and dark coloration with white stripes. Distinguished from Lymantria dispar by smaller size, different hair tuft arrangement, and preference for younger foliage. Microscopic examination of genitalia may be required for definitive identification in some regions.

Adult moths have white wings with a brownish abdomen tipped with conspicuous golden-brown hairs, giving the species its common name. Larvae are dark with white longitudinal stripes and possess numerous urticating (stinging) hairs arranged in tufts along the body. Full-grown larvae reach approximately 30 mm in length.

Primarily associated with forested and semi-forested environments. Found in oak-dominated woodlands, mixed deciduous forests, and areas with fruit tree cultivation. Populations on evergreen hosts (Arbutus unedo) occupy Mediterranean scrub and maquis vegetation. Occurs from sea level to montane elevations, with local adaptation to host plant phenology.

Native to Palearctic region: Europe (widespread from Scandinavia to Mediterranean), North Africa (Algeria, Morocco, Mauritania, Tunisia), and Asia (Turkey, Iran, Syria, China, Japan, Korea, Sakhalin). Introduced to North America (northeastern USA, eastern Canada), where established populations occur in Maine and adjacent regions. Present in Belgium, Netherlands, Germany, France, Spain, Portugal, Italy, and throughout Central and Eastern Europe.

Univoltine with one generation per year. Eggs laid in July; egg stage lasts approximately one month. Larval stage extends nine months, with overwintering as young larvae. Pupation occurs in spring for approximately one month. Adult emergence typically in July, though delayed emergence has been observed in dry conditions. Populations on evergreen Arbutus unedo exhibit shifted phenology with winter feeding from October to March.

Highly polyphagous folivore. Larvae feed on diverse woody plants including oak (Quercus), elm (Ulmus), poplar (Populus), hawthorn (Crataegus), and fruit trees (Prunus, Malus). During mass outbreaks, exhibits sequential host plant utilization, switching between species in a defined order as preferred hosts become depleted or population pressure increases. On evergreen strawberry tree (Arbutus unedo), larvae engage in winter feeding with arrested development during a true diapause period of approximately two months.

• Quercus - larval hostprimary host, major damage in oak forests
• Ulmus - larval hostdeciduous host with typical overwintering diapause
• Populus - larval hostrecorded host
• Crataegus - larval hostrecorded host
• Prunus - larval hostfruit tree host
• Arbutus unedo - larval hostevergreen host with shifted phenology and winter feeding

Complete metamorphosis with four stages: egg, larva, pupa, adult. Eggs laid in clusters on foliage. Larvae pass through multiple instars over nine months, typically entering diapause as young larvae in autumn. Pupation in silken cocoon on host plant or in ground litter. Adults non-feeding, short-lived. Generation time one year. Populations exhibit cyclical outbreak dynamics with 4-6 year cycles reported.

Larvae are gregarious, particularly in early instars, and construct silken webs for shelter. Sequential host plant switching occurs during outbreaks, with larvae moving between plant species in a predictable order. Winter feeding behavior observed on evergreen hosts represents a true diapause with arrested development, not continuous feeding. Larval dispersal by ballooning on silk threads has been reported. Adults are nocturnal and attracted to light.

Defoliator of broadleaf trees and shrubs; can function as outbreak pest causing significant forest damage. Serves as host for diverse parasitoid assemblages including wasps and flies. Microsporidian pathogens (Nosema, Endoreticulatus) regulate populations in some regions. Provides food source for insectivorous birds including storks, starlings, and finches. Urticating hairs contribute to anti-predator defense and may affect vertebrate foraging.

Significant forest and orchard pest causing economic damage to timber, fruit, and ornamental trees. Urticating larval hairs cause dermatitis, respiratory irritation, and allergic reactions in humans and livestock, necessitating caution during outbreak management. Subject to biological control efforts using bird conservation and parasitoid release. Chemical control complicated by resistance development and non-target effects on pollinators and beneficial insects. Subject to quarantine and management efforts in invaded North American range.

• Lymantria disparSimilar lymantriine moth with polyphagous larvae; distinguished by larger size, different larval color pattern (blue and red tubercles rather than dark with white stripes), and more pronounced sexual dimorphism in adults
• Euproctis similisCongeneric species with similar adult appearance; requires genitalia examination or molecular analysis for definitive separation
• Sphrageidus similisFormerly confused with E. chrysorrhoea; distinguished by adult morphology and larval hair arrangement

• pest
• defoliator
• urticating hairs
• univoltine
• polyphagous
• forest pest
• outbreak species
• host race
• phenological plasticity

• BugGuide
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Euproctis chrysorrhoea . [Distribution map].
• Euproctis chrysorrhoea . [Distribution map].
• Die Reihenfolge der Wirtspflanzen beim Massenauftreten von Euproctis chrysorrhoea L.
• IMPACTS OF EUPROCTIS CHRYSORRHOEA ON OAK FORESTS IN ARMENIA. FEEDING BEHAVIOR, DEFOLIATION PATTERNS, AND IMPLICATIONS FOR FOREST VULNERABILITY
• Euproctis chrysorrhoea Linnaeus, 1758 (Lepidoptera: Lymantriidae) biology and determination of damage Yedisu, Bingöl, Türkiye
• Common pheromone use among host-associated populations of the browntail moth, Euproctis chrysorrhoea, displaying different adult phenologies
• Parasitoids Attacking the Browntail Moth, Euproctis chrysorrhoea (Lepidoptera: Erebidae), during a Regional Outbreak in Maine, and Factors Influencing Their Abundance
• Genetic divergence and evidence for sympatric host-races in the highly polyphagous brown tail moth, Euproctis chrysorrhoea (Lepidoptera: Erebidae)
• Winter feeding leads to a shifted phenology in the browntail moth Euproctis chrysorrhoea on the evergreen strawberry tree Arbutus unedo
• First report on the distribution of microsporidian infections of browntail moth (Euproctis chrysorrhoea L.) populations in Bulgaria*
• Differences in Midgut Phosphatases Activity and Hemolymph Composition in Lymantria dispar and Euproctis chrysorrhoea Larvae Exposed to the Polycyclic Aromatic Hydrocarbon Fluoranthene.