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:38328
Specimens with Barcodes:37283
Species With Barcodes:4156
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