{{Short description|Species of moth}} {{Good article}} {{cs1 config|name-list-style=vanc|display-authors=6}} {{Speciesbox | name = ''Euproctis chrysorrhoea'' | image = Euproctis chrysorrhoea 1.jpg | image_caption = Upperside | image2 = Euproctis chrysorrhoea (Linnaeus, 1758).jpg | image2_caption = Female with tail tuft of red/brown hairs | taxon = Euproctis chrysorrhoea | authority = (Linnaeus, 1758) }} The '''brown-tail moth''' (''Euproctis chrysorrhoea'') is a moth of the family Erebidae. It is native to Europe, neighboring countries in Asia, and the north coast of Africa. Descriptions of outbreaks, i.e., large population increases of several years duration, have been reported as far back as the 1500s.<ref name=Fernald1903 /> The life cycle of the moth is atypical, in that it spends approximately nine months (August to April) as larvae (caterpillars), leaving about one month each for pupae, imagos and eggs. Larvae (caterpillars) are covered in hairs. Two red spots on the back, toward the tail, distinguish these species from other similarly hairy moth larvae. The winged adults have white wings and a hairy white body with a tuft of brown hair at the tip of the abdomen. Females lay one egg cluster, usually on the underside of a leaf of a host plant. The species is polyphagous, meaning that it feeds on many different species of trees, including pear, apple, maple and oak.
This species was accidentally introduced to the United States in the 1890s.<ref name=Fernald1903 /> During the early 20th century it was present from eastern Connecticut northward into New Brunswick, Canada, but a subsequent severe population collapse reduced the territory to parts of coastal Maine and Cape Cod, Massachusetts, by the late 20th century. One theory for the decline appeared to be parasitism by a fly introduced to combat spongy moths.<ref name=Elkinton2006/> Starting in 2015 there has been a population spike and territory expansion in coastal Maine.<ref name=MaineGov>{{cite web |url=https://www.maine.gov/dacf/mfs/forest_health/documents/browntail_moth_in_maine_history_and_current_situation_2018.pdf |title=Browntail Moth History, Background, Conditions in ME |date=February 2018 |website=Department of Agriculture, Conservation & Forestry, Maine Forest Service |access-date=25 July 2018}}</ref> In Europe, there are multiple parasitic and predator species,<ref name=Frago2011 /> yet there is still a history of population outbreaks.
Hairs from the caterpillars are toxic for humans,<ref name=MainePDF /> causing a poison ivy-like itchy rash of up to sometimes weeks-long duration due to mechanical and chemical irritation.<ref name=deJong1976/><ref name=deJong1982/> Direct contact with larvae is not necessary, as the hairs are shed and can become windblown.<ref name=MainePDF /> Toxins in the hairs remain potent for up to three years. Outdoor activities such as mowing a lawn or raking leaves in the fall can cause exposure.<ref name=MainePDF />
==Description== thumb|Caterpillar, dorsal view, showing two red dots near tail
The upper surface of the wings of this species is pure white. Males may have some brown color on the underside of the forewing. Wingspan is {{convert|36|–|42|mm}}. The body is very hairy and white except for the tail which is covered in reddish-brown hairs, much more prominent in the females.<ref name=Harpswell /> Males have larger antennae, used to detect pheromones released by unmated females. Females have a larger body.<ref name=Harpswell /> As winged adults, this species is superficially similar in appearance to ''Euproctis similis'' (native to Europe) and ''Hyphantria cunea'' (native to North America), but female ''E. similis'' have a yellow tail tuft and ''H. cunea'' lacks tail tuft coloration.
<gallery mode="packed"> Euproctis chrysorrhoea MHNT.CUT.2012.0.357 Claix (Isère) Female.jpg|Female Euproctis chrysorrhoea MHNT.CUT.2012.0.356. Les Mathes Male.jpg|Male </gallery>
The female lays one cluster of 200 to 400 eggs, typically on the underside of a leaf. The egg cluster is covered with hairs from her anal tuft.<ref name=Harpswell /> The larva is very hairy, brown with white markings, and two prominent red spots toward the tail end. The hairs provide protection from predators; the larva incorporates some into the cocoon within which it pupates.<ref>{{cite journal |last1=Candan |first1=S. |last2=Suludere |first2=Z. |last3=Bayrakdar |first3=F. |title=Surface morphology of eggs of ''Euproctis chrysorrhoea'' (Linnaeus, 1758) |journal=Acta Zoologica |date=2007 |volume=89 |issue=2 |pages=133–136 |doi=10.1111/j.1463-6395.2007.00300.x|url=https://www.researchgate.net/publication/238417405}}</ref> The species overwinters communally as larvae within a tough, silken tent constructed around branch-tip leaves and anchored to twigs. In areas where the species is abundant, these tents are a familiar sight, and can be seen on a huge range of plants, especially in late fall and winter when unaffected leaves have fallen.<ref name=MaineGov /><ref name=MainePDF>{{cite web |url=https://www.maine.gov/dacf/mfs/forest_health/documents/browntail_moth_brochure.pdf |title=Browntail Moth |website=Maine Department of Agriculture, Conservation and Forestry |access-date=24 July 2018}}</ref>
==Distribution==
===Native=== This species can be found throughout Europe, except in the most northern countries, also in the westernmost countries of Asia, such as Turkey, Syria and Israel, and the countries across the northern parts of Africa.<ref name=CABI>{{cite web |url=https://www.cabi.org/isc/datasheet/23353 |title=''Euproctis chrysorrhoea'' (brown-tail moth) |date=2018 |website=CABI Invasive Species Compendium. Wallingford, UK: CAB International |access-date=23 July 2018}}</ref> Charles H. Fernald and Archie H. Kirkland recount historic mentions of brown-tail moths dating back to 1500s, describing outbreaks in Paris, London and Berlin so severe as to completely strip all trees of leaves. Carl Linnaeus described the species in the tenth edition (1758) of ''Systema Naturae''.<ref name=Fernald1903 />
===Invasive=== The brown-tail moth is an invasive species in the United States and Canada, having arrived in Somerville, Massachusetts, circa 1890 and becoming widespread there and in neighboring Cambridge by 1897. Initial outbreaks were most evident in pear and apple trees. Doctors reported "poisonings" (skin rash) far worse than poison ivy rash. Within a few years it was seen as a serious, fast-spreading, horticultural and health problem.<ref name=Fernald1903>Fernald, Charles H. & Kirkland, Archie H. (1903). [https://archive.org/details/browntailmotheup00fern "The brown-tail moth, ''Euproctis chrysorrhoea'' (L.). A report on the life history and habits of the imported brown-tail moth, together with a description of the remedies best suited for destroying it"]. Wright & Potter Printing Co., Boston.</ref> Through the early parts of the 20th century it was present in much of New England from eastern Connecticut to Maine, and northward into New Brunswick, Canada, but the 1906 introduction of the parasitic tachinid fly ''Compsilura concinnata'' to counter spongy moths collaterally impacted brown-tail moths. By the late 20th century the habitat was reduced to the coast and islands of Maine, and also parts of Cape Cod, Massachusetts.<ref name=Elkinton2006>{{cite journal |author1=Elkinton, J. S. |author2=Parry, D. |author3=Boettner, G. H. |title=Implicating an introduced generalist parasitoid in the invasive browntail moth's enigmatic demise |journal=Ecology |volume=87 |issue=10 |pages=2664–2672 |date=2006 |pmid=17089674 |doi=10.1890/0012-9658(2006)87[2664:iaigpi]2.0.co;2 |url=https://works.bepress.com/joseph_elkinton/3/download/}}</ref> Cold and wet weather hinders re-expansion of the population outside its current territories,<ref name=Elkinton2008>{{cite journal |author1=Elkinton, J. S. |author2=Preisser, E. |author3=Boettner, G. |author4=Parry, D. |title=Factors influencing larval survival of the invasive browntail moth (Lepidoptera: Lymantriidae) in relict North American populations |journal=Environmental Entomology |volume=37 |issue=6 |pages=1429–1437 |date=2008 |pmid=19161686 |doi=10.1603/0046-225x-37.6.1429|s2cid=11928538 |doi-access=free }}</ref> although starting in 2015 there has been a population spike and territory expansion in coastal Maine, from Portland to Bar Harbor.<ref name=MaineGov /> In addition to North America, there have been reports of this species appearing in China, Japan and New Guinea.<ref name=CABI />
===Detection=== Photographs taken from aerial fly-overs are used to identify areas where the trees have been denuded of leaves and where the branch-tip tents are present.<ref name=MaineGov /> The female sex hormone has been synthesized and field-tested in moth traps as a means of monitoring moth populations during the June/July flight season.<ref>{{cite journal |author1=Khrimian, A. |author2=Lance, D. R. |author3=Schwarz, M. |author4=Leonhardt, B. A. |author5=Mastro, V. C. |title=Sex pheromone of browntail moth, ''Euproctis chrysorrhoea'' (L.): synthesis and field deployment |journal=Journal of Agricultural and Food Chemistry |volume=56 |issue=7 |pages=2452–2456 |date=2008 |pmid=18333615 |doi=10.1021/jf073161w|bibcode=2008JAFC...56.2452K }}</ref> The white-winged adults are nocturnal and strongly attracted to light; a report from 1903 likened their appearance around streetlights as being akin to heavy snowfall.<ref name=Fernald1903 />
==Life cycle== The brown-tail moth produces one generation a year. It has four life stages; egg, larval, pupal, and adult. Eggs are laid in July and hatch in August.<ref name=Harpswell>{{cite web |url=https://hhltmaine.org/controlling-browntail-moths-lay-eggs/ |title=Controlling Browntail moths as they lay eggs |date=2 August 2016 |website=Harpswell Heritage Land Trust, Harpswell, Maine |access-date=10 July 2018}}</ref> The annual cycle is approximately one month as eggs, nine months as larvae, one month as pupae, and one month as imagoes (winged, sexually mature adults).<ref name=Frago2010 /> # Eggs are preferentially laid on oak trees. # Pre-diapausing larvae: Emerge and feed gregariously starting in August after about three weeks of egg incubation. # Diapausing larvae: As a response to shortened periods of daylight, larvae build communal winter nests in the fall, inside of which they overwinter. These involve webbing binding leaves together at tree-top branch tips. Distinct from other communal moth larvae such as eastern tent caterpillar which over-winter as eggs, then create webbed nests in branch crotches during spring and summer. # Post-diapausing gregarious larvae: The emerging larvae, approximately one centimeter long, resume feeding in early April synchronized with bud break, and still inhabit the winter nests as their resting places, or else make communal web-nests. These small larvae will also detach from trees and fall to the ground, then search for new trees. # Post-diapausing dispersive larvae: Once larvae reach late instars, colonies break up and larvae start feeding independently. # Pupation: Larvae pupate in June after six to eight instars. # Emergence: Imagoes (winged, sexually mature adults) appear about one month later; mate, lay eggs and die.<ref name=Frago2010 />
===Predators, parasites and diseases=== In the United States, many species of birds prey on the winged adults, including English house sparrow and blue jay.<ref name=Fernald1903 /> In a study conducted in England, egg, larvae and pupae deaths were attributed to several parasites, including microsporidia, cytoplasmic and nuclear viruses, and larvae predation by birds, specifically identifying the common cuckoo (''Cuculus canorus'') and titmice.<ref name=Sterling1989>{{cite journal|last1=Sterling |first1=P. H. |last2=Speight |first2=M. R. |date=1989|title=Comparative mortalities of the brown-tail moth, ''Euproctis chrysorrhoea'' (L.) (Lepidoptera: Lymantriidae), in south-east England|journal=Botanical Journal of the Linnean Society |volume=101|pages= 69–78 |doi=10.1111/j.1095-8339.1989.tb00137.x}}</ref> A more recent review, conducted in Spain, identified 17 species of parasites, viral diseases, unspecified predation and other, unknown, causes of death spanning from eggs not hatching, during summer, winter and spring as larvae, finishing with pupae failing to produce winged adults. Generally, mortality increased with population density, although in outbreak regions there was some compensation by females laying 21.6% more eggs (cause not discussed).<ref name=Frago2011>{{cite journal |last1=Frago |first1=E. |last2=Pujade-Villar |first2=J. |last3=Guara |first3=M. |last4=Selfa |first4=J. |title=Providing insights into browntail moth local outbreaks by combining life table data and semi-parametric statistics |journal=Ecological Entomology |date=2011 |volume=36 |issue=2 |pages=188–199 |doi=10.1111/j.1365-2311.2010.01259.x |bibcode=2011EcoEn..36..188F |s2cid=83507161 |url=https://www.researchgate.net/publication/230472280}}</ref>
''Compsilura concinnata'', a parasitic fly, pierces the brown-tail moth larva and deposits its own larva inside. This fly was introduced to North America in 1906 in an attempt to counter spongy moth, an invasive species. While not entirely successful for that purpose, one research group concluded that introduction of this fly had a great impact on brown-tail moths while not being as effective on spongy moths, the reason being that the fly larvae need to over-winter inside a host larvae. (Brown-tail moths over-winter as larvae, whereas spongy moths over-winter as eggs.)<ref name=Elkinton2006 /> An older review describes other fly species that were confirmed as brown-tail moth larvae parasites, then released in U.S.: ''Apanteles lacteicolor'', ''Metrous versicolor'' and ''Sturmia nidicola''.<ref>{{cite web |url=http://ageconsearch.umn.edu/record/156566/files/tb86.pdf |title=Imported insect enemies of the gypsy moth and the brown-tail moth |last=Burgess |first=A. F. |author-link=Albert Franklin Burgess |date=1929 |website=U.S. Department of Agriculture, Washington, DC |access-date=23 July 2018}}</ref>
===Control=== Branch-tip webs can be clipped in winter and very early spring, and either dropped into a bucket of soapy water or burned. Gloves should be worn. Appropriate pesticides should be applied before early May because that is when the larvae start to develop harmful hairs. For organic garden and farm situations there are sprays that use a strain of ''Bacillus thuringiensis'' (Bt).<ref name=MainePDF />
===Population explosions=== [[File:Life cycle of the brown-tail moth.jpg|thumb|Colour plate from a pamphlet by William Curtis illustrating the moth's life cycle, intended to address public fear during a 1782 population explosion.]]
Historically the brown-tail moth has undergone periodic population outbreaks, each developing rapidly and lasting for months to years.
Population explosions in Maine in 2003 and 2016 caused widespread ecological damage, with more than 10,000 hectares affected in the latter case.<ref>{{cite journal |last1=Boyd |first1=Karla S. |last2=Drummond |first2=Francis |last3=Donahue |first3=Charlene |last4=Groden |first4=Eleanor |title=Factors Influencing the Population Fluctuations of Euproctis chrysorrhoea (Lepidoptera: Erebidae) in Maine |journal=Environmental Entomology |date=October 2021 |volume=50 |issue=5 |pages=1203-1216 |doi=10.1093/ee/nvab060 |url=https://academic.oup.com/ee/article/50/5/1203/6310266 |access-date=13 February 2026|pmc=8506827 }}</ref>
Réaumur recorded a devastating outbreak in France in 1730 near Paris.<ref>{{cite book |last1=de Réaumur |first1=René Antoine Ferchault |title=Mémoires pour servir a l'histoire des insectes. 2 |date=1736 |publisher=Imprimerie Royale |location=Paris |pages=131-2 |url=https://preserver.beic.it/delivery/DeliveryManagerServlet?dps_pid=IE3240957 |access-date=13 February 2026}}</ref>
An outbreak of caterpillars in London in 1782, when the city was still recovering from the Gordon Riots eighteen months before, caused widespread panic and fears of famine and plague. Contemporary scientists such as William Curtis attempted to calm public fears; it is unclear how much effect this had.<ref name="LidwellDurnin23">{{cite journal |last1=Lidwell-Durnin |first1=J. |title=Plague, Crisis, and Scientific Authority during the London Caterpillar Outbreak of 1782 |journal=The Historical Journal |date=2023 |volume=66 |issue=1 |pages=49-71 |doi=10.1017/S0018246X22000048 |url=https://www.cambridge.org/core/journals/historical-journal/article/plague-crisis-and-scientific-authority-during-the-london-caterpillar-outbreak-of-1782/446D4AA3D0A3D10544B7195422B820E5 |access-date=13 February 2026|hdl=10871/129462 |hdl-access=free }}</ref>
==Health issues== right|200px|thumb|Skin rash caused by the exposure to hairs shed by brown-tail moth larva
Cicely Blair wrote a paper about the rash caused by the brown-tail moth caterpillar in the British Isles.<ref>{{cite journal |last1=Blair |first1=C. P. |title=The browntail moth, its caterpillar and their rash |journal=Clinical and Experimental Dermatology |date=1979 |volume=4 |issue=2 |pages=215–222 |doi=10.1111/j.1365-2230.1979.tb01621.x|pmid=498574 |s2cid=31576760 }}</ref> It, and other descriptions, confirmed that loose hairs can break off and cause very itchy rashes on contact with skin, as well as breathing difficulties similar to asthma if inhaled. Rashes can persist for weeks.<ref name=deJong1976/><ref name=deJong1982/><ref>{{cite book|author1=Mabey, Richard |author2=Marren, Peter |title=Bugs Britannica |date=2010 |publisher=Random House UK |page=273 |isbn=9780701181802 |edition=Illustrated |url=https://books.google.com/books?id=B1JFAQAAIAAJ |access-date=7 January 2016}}</ref><ref>{{cite news|last1=Graham |first1=Gillian |title=Got an itchy rash? Browntail moths out in force in Maine, spreading noxious hairs |url=http://www.pressherald.com/2015/07/23/maine-officials-warn-of-infestations-of-noxious-browntail-moth/ |access-date=26 May 2016 |work=Portland Press Herald |date=23 July 2015}}</ref> The same symptoms have been reported as far back as 1903.<ref name=Fernald1903 /> The reactions are due to a combination of mechanical and chemical stimuli, the barbed hairs in effect becoming lodged in and physically irritating the skin, and also functioning as microtubules to introduce irritating chemical compounds that have hydrolase, esterase and hemolytic activity.<ref name=deJong1976>{{cite journal |author1=de Jong, M. C. |author2=Hoedemaeker, J. |author3=Jongebloed, W. L. |author4=Nater, J. P. |title=Investigative studies of the dermatitis caused by the larva of the brown-tail moth (''Euproctis chrysorrhoea'' Linn.) II. Histopathology of skin lesions and scanning electron microscopy of their causative setae |journal=Archives of Dermatological Research |volume=255 |issue=2 |pages=177–191 |date=1976 |pmid=1275552 |doi= 10.1007/bf00558526|s2cid=22982885 }}</ref><ref name=deJong1982>{{cite journal |author1=de Jong, M. C. |author2=Kawamoto, F. |author3=Bleumink, E. |author4=Kloosterhuis, A. J. |author5=Meijer, G. T. |title=A comparative study of the spicule venom of ''Euproctis'' caterpillars |journal=Toxicon |volume=20 |issue=2 |pages=477–485 |date=1982 |pmid=7043788 |doi=10.1016/0041-0101(82)90011-3|bibcode=1982Txcn...20..477D }}</ref> This rash reaction may be referred to as lepidopterism. The species should be handled using protective gloves at all stages of its life cycle. Shed hairs blow about, and can be brought indoors on clothing and shoes, so rashes can occur without the victim coming in direct contact with the caterpillars. The toxins in the hairs remain potent for up to three years after being shed. Outdoor activities such as mowing a lawn or raking leaves in the fall can cause exposure.<ref name=MaineGov /><ref name=MainePDF />
A related species, mistletoe browntail moth (''Euproctis edwardsi''), has been reported as causing a similar rash in Australia, in people working at or visiting a community center, attributed to caterpillars feeding on a tree outside the building.<ref>{{cite journal |author1=Balit, C. R. |author2=Ptolemy, H. C. |author3=Geary, M. J. |author4=Russell, R. C. |author5=Isbister, G. K. |title=Outbreak of caterpillar dermatitis caused by airborne hairs of the mistletoe browntail moth (''Euproctis edwardsi'') |journal=Medical Journal of Australia |volume=175 |issue=11–12 |pages=641–643 |date=2001 |pmid=11837874 |doi= 10.5694/j.1326-5377.2001.tb143760.x|s2cid=26910462 }}</ref> In addition to brown-tail and mistletoe browntail, several other ''Euproctis'' species are identified as causing rashes in humans, including ''Euproctis baliolalis'', ''Euproctis limbalis'' and ''Euproctis lutea'' (all three native to Australia). Urticating hairs, i.e., itch and rash-producing, are also reported for caterpillars of other moth and butterfly species.
==Host plants== Brown-tail larvae have been reported as feeding on 26 genera of non-resinous trees and shrubs belonging to 13 different families. This polyphagy is considered unusual. Non-specific host plant feeding combined with its tendency to reach extreme outbreak densities makes this species a major pest of fruit orchards, ornamental trees and hardwood forests.<ref name=Frago2010>{{cite journal |last1=Frago |first1=E. |last2=Guara |first2=M. J. |last3=Pujade-Villar |first3=J.|last4=Selfa |first4=S. |date=2010 |url= https://www.researchgate.net/publication/236160929|title= Winter feeding leads to a shifted phenology in the browntail moth ''Euproctis chrysorrhoea'' on the evergreen strawberry tree ''Arbutus unedo'' |journal=Agricultural and Forest Entomology |volume=12 |issue=4 |pages=381–388 |doi=10.1111/j.1461-9563.2010.00489.x|s2cid=85141544 }}</ref> Partial list of plant species: apple, cherry, beach plum (Cape Cod, Massachusetts), beech, elm, grape, hops, maple, oak, pear, raspberry, rose and willow, and even conifers like spruce and hemlock. An early description of the introduction to the United States in the 1890s identified pear and apple trees as most greatly afflicted, but mentioned that once trees were entirely bare of leaves, the larvae would descend to the ground in great numbers and move toward any leafy plant, including vegetable plants.<ref name=Fernald1903 /> A population explosion on Orford Ness, Suffolk, Uk in 2023-2024 has denuded wild bramble/blackberry bushes.{{citation needed|date=August 2024}}
==Gallery== <gallery widths="220" heights="160"> File:Euproctis chrysorrhoea (Brown-tail), Texel, the Netherlands.jpg|Oviposition of hair-covered egg mass containing 200-400 eggs File:Euproctis chrysorrhoea-posta.jpg|Egg mass covered with brown hairs from body of the egg-laying female File:Euproctis chrysorrhoea (caterpillar) R.H (16).JPG|The protective communal silken tent. Created in the fall, the larvae over-winter inside, emerging in spring. File:Goldafter Gespinst.jpg|Group of larvae on branch-tip nest. Once larvae reach late instars, colonies break up and larvae feed independently. File: Lymantriidae - Euproctis chrysorrhoea.JPG|Caterpillar, dorsal view, showing two red dots toward tail end that differentiate it from other hairy caterpillars </gallery>
== References == {{Reflist}}
==External links== {{Commons category|Euproctis chrysorrhoea}} *{{cite web |last=Kimber |first=Ian |url=https://www.ukmoths.org.uk/species/euproctis-chrysorrhoea/ |title=72.012 BF2029 Brown-tail ''Euproctis chrysorrhoea'' (Linnaeus, 1758) |website=UKMoths |access-date=March 27, 2020}} *{{cite web |last=Savela |first=Markku |date=July 2, 2019 |url=https://www.nic.funet.fi/pub/sci/bio/life/insecta/lepidoptera/ditrysia/noctuoidea/erebidae/lymantriinae/euproctis/#chrysorrhoea |title=''Euproctis chrysorrhoea'' (Linnaeus, 1758) |website=Lepidoptera and Some Other Life Forms |access-date=March 27, 2020}} *[http://www.lepiforum.de/lepiwiki.pl?Euproctis_Chrysorrhoea "10405 ''Euproctis chrysorrhoea'' (Linnaeus, 1758) - Goldafter"]. ''Lepiforum e. V.'' Retrieved March 27, 2020. {{in lang|de}}
{{Taxonbar|from=Q45902}} {{Authority control}}
{{DEFAULTSORT:Brown-Tail}} Category:Insect pests of temperate forests Category:Lymantriinae Category:Moths described in 1758 Category:Moths of Europe Category:Moths of North America Category:Moths of Asia Category:Animal taxa named by Carl Linnaeus