The Arctiidae tend to be a colorful, charismatic lineage. Over 11,000 species have been described. Arctiids represent roughly 6% of lepidopteran species diversity worldwide (Watson and Goodger, 1986; Goodger and Watson, 1995) and are an important component of Neotropical communities (Conner 2008). Their bright colors most likely function in predator defense, warning of the moths’ unpalatability. Many species are protected by compounds they produce themselves (e.g. histamines) or by compounds they acquire from their larval host plants (e.g., cardiac glycosides, pyrrolizidine alkaloids). Some chemically protected arctiids participate in Müllerian mimicry rings and may resemble other poisonous Lepidoptera or wasps. Some species are nearly identical with their wasp models (Simmons and Weller, 2006) and even mimic wasp behaviors (Blest, 1964). Arctiid larvae typically have secondary setae arranged on verrucae on all segments except the head, hence their common name “wooly bears.” The caterpillar of *Pyrrharctia isabella* (J.E. Smith) is familiar to many North Americans. Not all caterpillars, though, have secondary setae.
Over 11,000 species have been described. Most recent Arctiids represent roughly 6% of lepidopteran species diversity worldwide (Watson and Goodger, 1986; Goodger and Watson, 1995) and are an important component of Neotropical communities (see Chapter 16 in Conner 2008). Although the family is cosmopolitan, some lineages are restricted in their distribution.
These small- to medium-large moths have whip-like antennae and are usually brightly colored. Their caterpillars construct cocoons consisting primarily of larval hairs
Nearctic, Palearctic, Oriental, Ethiopian, Neotropical, Australian, Oceanic Island
Although the family is cosmopolitan, some lineages are restricted in their distribution.
Body setae on verrucae:
Body setae on scoli:
Pairs of thoracic legs:
Pairs of abdominal legs:
Crochet arrangement description:
Most larvae have heteroideous crochets. Lithosiinae, Syntominae and *Virbia* (Arctiinae) possess homoideous crochets, the general noctuoid condition. Outside of Arctiidae, some Euteliinae ("Noctuidae") have heteroideous crochets (Forbes 1960).
Adult Abdomen Morphology
Female genitalia description:
A diversity of female genitalic morphologies have been documented and it is a very useful character system for phylogenetic studies at the suprageneric, generic and species' level. Homology of the appendix bursa, when present, can be probablematic to assign (e.g., *Virbia*, Zaspel and Weller 2006)
Female pregenital sexual scales:
Female oviduct opening:
Female bursa ostium opening:
between S7 and venter 8, on venter 8
Female anterior apophyses originating:
originating from T8, from venter 8
Male pregenital sexual scales:
Male genitalia description:
Male genitalia highly diverse in some lineages. It is a very useful character system for phylogenetic studies at the suprageneric, generic and species' level. Within the *Sphecosoma* group and other Euchromiini, highly asymmetrical and divided valves occur (Simmons
Adult Thorax Morphology
Adult thorax description:
Variously developed depending on lineage and species.
Thorax tympanum description:
In general, the tympanal membrane outward and posteriorly directed with a nodular sclerite.
Adult Head Morphology
porrect, upcurved, large
Number of labial palp segments:
present, absent, reduced
Head vertex scaling:
bipectinate, dentate, filiform, moniliform, serrate
bipectinate, dentate, filiform, pectinate, serrate
Adult female dorsal invaginated pheromone glands visible, with horizontally paired openings. Metathoracic tymbal. Larval ventral eversible gland. Tympanum pocket IV present. Larval mandible with indentation on dorsal tooth
Life History and Behavior
diurnal, nocturnal, crepuscular
The male courtship behaviors have been documented for several arctiid species including: *Utetheisa ornatrix*, *Euchaetes bolteri*, *Cycnia tenera*, *Syntomeida epilais*, *Cosmosoma myradora*, *Empyreuma pugione*, *Halysidota davisii*, *Estigmene acrea* and *Amerila* species (formerly *Rhodogastria*). Male courtship can include PA-derived pheromones, non-PA based pheromones or ultrasonic clicks emitted by tymbals. There is a growing literature on the diversity of mating systems in arctiids and their evolution (Conner 2008, references therein).
Life History: Immature Stages
Various feeding habits have been recorded in this family from polyphagy to monophagy. Many monophagous species are associated with pyrrolizidine alkaloid hosts. *Tyria jacobaeae* (L) the cinnabar moth is used for biological control of ragwort (Senecio) in the western United States. Several species feed on cardiac glycoside hosts as larvae (e.g., *Euchaetes bolteri*, *Syntomeida epilais*).
Life history larvae:
For an authoritative treatment, consult Wagner 2008.
Life History: Adults
Several arctiid species are pharmacophagous (Boppré 1990), although records are concentrated in the Phaegopterini (Pliske 1975a, 1975b), especially the *Eupseudosoma* group and the *Halysidota* generic group of Watson and Goodger (1986). Typically males collect pyrollizidine alkaloids (PAs) from withered or damaged leaves of PA plants by regurgitating saliva and then re-imbibing the salivary fluid with the dissolved PAs. There are a few species were both sexes collect PAs and in even fewer just females collect (Pliske 1975a, 1975b). PAs are bitter tasting and are used in defense and courtship by arctiids (reviews Weller et al. 1999, Conner and Weller 2001, Conner 2008 and references therein).
Evolution and Systematics
Systematic and taxonomic history
Traditionally, Arctiidae has been placed as sister to Lymantriidae, and four taxa—Aganainae (=Hypsidae), Nolinae, Hermiinae, and Pantheinae — have been treated either as subfamilies of Arctiidae, subfamilies of Noctuidae, or as separate families allied to Arctiidae (review Kitching and Rawlins, 1999; Jacobson and Weller, 2002; Fibiger and Lafontaine, 2005). A series of molecular studies in the 1990s and early 2000s suggested that “Noctuidae” was not a monophyletic entity. “Quadrifine” noctuid subfamilies form a clade with Arctiidae and Lymantriidae, and the traditional “trifine” noctuids form another clade (Weller et al., 1994; Mitchell et al., 1997, 2000; Fig. 3.6; the terms “trifine” and “quadrifine” refer to the position of M3 in the hind wing; see reviews). The taxonomic history of the Arctiidae is complicated because many distantly related species bear a superficial resemblance to one another. Species have been placed in different superfamilies and in as many as six separate families: Arctiidae, Ctenuchidae [=Euchromiidae or =Syntomidae of authors], Lithosiidae, Nyctemeridae, Pericopidae, and Thyretidae (review Jacobson and Weller, 2002). Two additional families—Aganaidae [=Hypsidae] and Nolidae—have been placed as subfamilies or associated closely with them in phyletic lists (see reviews by Kitching and Rawlins, 1999; Jacobson and Weller, 2002; Fibiger and Lafontaine, 2005). The number and composition of other suprageneric groupings (i.e., subfamilies, tribes, generic groups) have also been in flux (Kitching and Rawlins, 1999; DaCosta and Weller, 2005; Fibiger and Lafontaine, 2005). Some workers even erected explicitly artificial groups to accommodate species that would not easily fit elsewhere (e.g., Microarctiinae, Seitz, 1913, 1933). A recurring problem has been the tendency of workers to revise local faunas without reconciling their taxonomic systems with those of other regions (e.g., Callimorphini; review DaCosta and Weller, 2005). Currently, three subfamilies (Arctiinae, Lithosiinae, Syntominae) are recognized (review Weller et al. 2008). Lithosiinae and Syntominae form a clade and are sister to the remaining Arctiinae in morphological and molecular analyses. The Syntominae is comprised of two tribes, Syntomini and Thyretini. The Lithosiinae is comprised of 7 tribes (Bendib and Minet 1999): Nudariini Börner 1920, Endrosini Börner 1932, Lithosiini Stephens 1829, Phryganopterygini Bendib and Minet 1999, Acsalini Bendib and Minet 1999 (formal description of Acsalini Franclemont 1983), Eudesmiini Bendib and Minet 1999, and Cisthenini Bendib and Minet 1999. The Arctiinae is comprised of 6 tribes: Arctiini, Callimorphini, Phaegopterini, Pericopini, Ctenuchini, and Euchromiini. However, only Callimorphini (DaCosta and Weller 2005) is demonstrably monophyletic. Euchromiini, Ctenuchini and Phaegopterini are not monophyletic. The taxonomic and biology information for these subfamilies and constituent tribes are summarized on their taxon information pages.
Molecular Biology and Genetics
Statistics of barcoding coverage
Specimens with Sequences:39806
Specimens with Barcodes:38728
Species With Barcodes:4188
The Arctiinae (formerly called the Arctiidae) are a large and diverse subfamily of moths, with around 11,000 species found all over the world, including 6,000 neotropical species. This group includes the groups commonly known as tiger moths (or tigers), which usually have bright colours, footmen (which are usually much drabber), lichen moths, and wasp moths. Many species have 'hairy' caterpillars which are popularly known as woolly bears or woolly worms. The scientific name refers to this (Gk. αρκτος = a bear). Caterpillars may also go by the name 'tussock moths' (more usually this refers to Lymantriidae, however).
The subfamily was previously classified as the Arctiidae family of the Noctuoidea superfamily and is a monophyletic group. Recent phylogenetic studies have shown that the group is most closely related to litter moths Herminiinae and the Old World Aganainae, which are subfamilies of the Erebidae family. The Arctiidae as a whole have been reclassified to represent this relationship. The family was lowered to subfamily status as the Arctiinae within the Erebidae. The subfamilies and tribes of Arctiidae were lowered to tribes and subtribes, respectively, of this new Arctiinae to preserve the internal structure of the group.
|Taxon rank||Former classification||Current classification|
|Subfamily||Arctiinae, Lithosiinae, Syntominae||Arctiinae|
|Tribe||Arctiini, Ctenuchini, Eudesmiini, Lithosiini, etc.||Arctiini, Lithosiini, Syntomini|
|Subtribe||—||Arctiina, Ctenuchina, Eudesmiina, Lithosiina, etc.|
|Genus||Many genera||Names and rank not changed|
|Species||Many species||Names and rank not changed|
|Taxa of the same background color represent the same group of species before and after its lowering of taxonomic rank, despite the change of suffixes.|
Tribes (former subfamilies)
Many genera are classified into the following tribes, while others remain unclassified (Incertae sedis).
The most distinctive feature of the subfamily is a tymbal organ on the metathorax. This organ has membranes which are vibrated to produce ultrasonic sounds. They also have thoracic tympanal organs for hearing, a trait which has a fairly broad distribution in the Lepidoptera, but the location and structure is distinctive to the subfamily. Other distinctive traits are particular setae ('hairs') on the larvae, wing venation, and a pair of glands near the ovipositor. The sounds are used in mating and for defense against predators. Another good distinguishing character of the subfamily is presence of anal glands in females.
Many species retain distasteful or poisonous chemicals acquired from their host plants. Some species also have the ability to make their own defenses (Nishida, 2002). Common defenses include: cardiac glycosides (or cardenolides), pyrrolizidine alkaloids, pyrazines and histamines. Larvae usually acquire these chemicals, and may retain them in the adult stage. But adults can acquire them too, by regurgitating on decomposing plants containing the compounds, and sucking up the fluid. Adults can transfer the defenses to their eggs, and males sometimes transfer them to females to help with defense of the eggs. Larval 'hairs' may be stinging, due to histamines the caterpillar makes, in some species but not all.
The insects advertise these defenses with aposematic bright coloration, unusual postures, odours, or, in adults, ultrasonic vibrations. Some mimic moths that are poisonous, or wasps that sting. The ultrasound signals help nocturnal predators to learn to avoid the moths, and for some species can jam bat echolocation.
Behavior and life cycle
Many of the caterpillars and adults are active during the daytime; however, most part of species are night-flying. Moths are attracted by light; but there is one species, Borearctia menetriesii that never comes to light. Basking to accelerate digestion is common in the larval stages, and social behaviour may range from solitary to gregarious. Like most Lepidoptera, larvae produce a small silk pad before each moult, in which their prolegs are engaged.
If disturbed, woolly bear caterpillars will roll into a tight spiral or drop from their perch suspended by a strand of silk. Isabella tiger moths (Pyrrharctia isabella) overwinter in the caterpillar stage. They can survive freezing at moderate subzero temperatures by producing a cryoprotectant chemical. The larvae of another species, Phragmatobia fuliginosa, may be found on snow seeking a place to pupate. Species in Arctic and temperate belts overwinter in larval stage.
Many species are polyphagous in larva stage. Monophagous species, like Cinnabar moth, Tyria jacobaeae are scarce.
Although abundant, few species in this subfamily are of economic importance. Even the fall webworm, an abundant and highly polyphagous tree-feeding species that has spread from North America to Asia and Europe, does not do lasting damage to healthy hosts.
Local folklore of the American Northeast and the American South hold that "woolly bears" (or "wooly worms" in the South) have the ability to predict the weather, similar to that of the groundhog. The forthcoming severity of a winter may be indicated by the amount of black on the Isabella tiger moth's caterpillar—the most familiar woolly bear in North America. More brown than black is said to mean a mild winter, but more black than brown is supposed to mean a harsh winter. However, the relative width of the black band varies among instars, not according to weather. The mythical qualities attributed to woolly bears in America have led to such things as the Woollybear Festival in Ohio, the Wooly Worm Festival in Beattyville, Kentucky and the Wooly Worm Festival in Banner Elk, North Carolina.
- Banded tussock moth, Halysidota tesselaris
- banded woolly bear or Isabella tiger moth, Pyrrharctia isabella
- Buff ermine, Spilarctia lutea
- Cinnabar moth, Tyria jacobaeae
- common footman, Manulea lurideola
- dogbane tiger moth or delicate cycnia, Cycnia tenera
- fall webworm, Hyphantria cunea
- garden tiger moth, Arctia caja
- Grote's Bertholdia, Bertholdia trigona
- giant leopard moth, Hypercompe scribonia
- hickory tussock moth, Lophocampa caryae
- Jersey tiger moth, Euplagia quadripunctaria
- milkweed tussock moth, Euchaetes egle
- scarlet tiger moth, Callimorpha dominula
- Maltese ruby tiger moth, Phragmatobia fuliginosa ssp. melitensis
- Ornate Moth, Utetheisa Ornatrix
Notes and references
- Scoble, MJ. (1995) The Lepidoptera: Form, Function and Diversity. Second ed. Oxford University Press.
- Fibiger, Michael; Hacker, Hermann (June 29, 2005). "Systematic List of the Noctuoidea of Europe (Notodontidae, Nolidae, Arctiidae, Lymantriidae, Erebidae, Micronoctuidae, and Noctuidae)". Esperlana 11: 93–205.
- Zahiri, Reze; et al. (2011). "Molecular phylogenetics of Erebidae (Lepidoptera, Noctuoidea)". Systematic Entomology. doi:10.1111/j.1365-3113.2011.00607.x.
- Lafontaine, Donald; Schmidt, Christian (19 Mar 2010). "Annotated check list of the Noctuoidea (Insecta, Lepidoptera) of North America north of Mexico". Zookeys 40: 26. doi:10.3897/zookeys.40.414.
- Simmons RB, Conner WE. (1996). "Ultrasonic signals in the defense and courtship of Euchaetes egle Drury and E. bolteri Stretch" (Lepidoptera: Arctiidae). Journal of Insect Behavior 9 (6): 909–919. doi:10.1007/BF02208978
- Fullard JH, Simmons JA, Sailant PA (1994) Jamming bat echolocation: the dogbane tiger moth Cycnia tenera times its clicks to the terminal attack calls of the big brown bat Eptesicus fuscus. Journal of Experimental Biology 194:285–298
- Holloway JD. (1988). The Moths of Borneo 6: Family Arctiidae.
- Weller SJ, Jacobsen NL, Conner WE (1999) The evolution of chemical defenses and mating systems in tiger moths (Lepidoptera: Arctiidae). Biol J Linn Soc 68:557–578.
- Simmons RB, Weller SE (2002) What kind of signals do mimetic tiger moths send? A phylogenetic test of wasp mimicry systems (Lepidoptera: Arctiidae: Euchromiini). Proc Roy Soc Lond B 269: 983–990
- Dunning DC, Roeder KD (1965) Moth sounds and the insect-catching behavior of bats. Science 147:173–174
- Hristov NI, Conner WE (2005) Sound strategy: acoustic aposematism in the bat–tiger moth arms race. Naturwissenschaften 92:164–169. doi:10.1007/s00114-005-0611-7
- Layne JR, Kuharsky DK (2000) Triggering of cryoprotectant synthesis in the woolly bear caterpillar (Pyrrharctia isabella Lepidoptera : Arctiidae). J Exper Zool 286 (4): 367–371
- Wagner, DL, (2005) Caterpillars of Eastern North America. Princeton University Press.
- Bates DL, Fenton MB (1990) Aposematism or startle? Predators learn their responses to the defenses of prey. Can J Zool 68:49–52
- Dunning DC, Krüger M (1995) Aposematic sounds in African moths. Biotropica 27:227–231
- Dunning DC, Acharya L, Merriman CB, Ferro LD (1992) Interactions between bats and arctiid moths. Can J Zool 70:2218–2223
- Fullard JH, Fenton MB, Simmons JA (1979) Jamming bat echolocation: the clicks of arctiid moths. Can J Zool 57:647–649
- Science Fridays: Moths Can Escape Bats By Jamming Sonar
Main species catalogs
- Dubatolov VV (2010) Tiger-moths of Eurasia (Lepidoptera, Arctiidae) (Nyctemerini by Rob de Vos & Vladimir V. Dubatolov). Neue Entomologische Nachrichten 65:1–106
- Edwards ED (1996) Arctiidae. Monographs on Australian Lepidoptera 4:278–286, 368–370
- Ferguson DC, Opler PA (2006) Checklist of the Arctiidae (Lepidoptera: Insecta) of the continental United States and Canada. Zootaxa 1299:1–33
- Goodger DT, Watson A (1995) The Afrotropical Tiger-Moths. An illustrated catalogue, with generic diagnosis and species distribution, of the Afrotropical Arctiinae (Lepidoptera: Arctiidae). Apollo Books Aps.: Denmark, 55 pp.
- Watson A (1971) An illustrated Catalog of the Neotropic Arctiinae type in the United States National Museum (Lepidoptera: Arctiidae) Part 1. Smithsonian Contributions to Zoology 50:1–361
- Watson A, Goodger DT (1986) Catalogue of the Neotropical Tiger-moths. Occasional Papers on Systematic Entomology 1:1–71
- Da Costa MA, Weller SJ (2005) Phylogeny and classification of Callimorphini (Lepidoptera: Arctiidae: Arctiinae). Zootaxa 1025:1–94
- Dubatolov VV (2006) Cladogenesis of tiger-moths of the subfamily Arctiinae: development of a cladogenetic model of the tribe Callimorphini (Lepidoptera, Arctiidae) by the SYNAP method. Euroasian Entomological Journal 5(2):95–104 (in Russian).
- Dubatolov VV (2008) Construction of the phylogenetic model for the genera of the tribe Arctiini (Lepidoptera, Arctiidae) with the SYNAP method. Entomological Review 88(7):833-837. Translated from: Entomologicheskoe Obozrenie 87(3):653–658
- Dubatolov VV (2009) Development of a phylogenetic model for the tribe Micrarctiini (Lepidoptera, Arctiidae) by the SYNAP method. Entomological Review 89(3):306–313. Translated from: Zoologicheskii Zhurnal. 88(4):438–445
- Jacobson NL, Weller SJ (2002) A cladistic study of the Arctiidae (Lepidoptera) by using characters of immatures and adults. Thomas Say publications in entomology. Entomological Society of America | Lanham, Maryland, 98 pp.
- Dubatolov VV (2008) Analysis of Insect Distribution in the Northern Hemisphere by the Example of the Subfamily Arctiinae (Lepidoptera, Artctiidae). Contemporary Problems of Ecology 1(2):183–193, 194–203.
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