Riodinidae are a pantropical family, with the majority of species occurring in the neotropics.
Although Erycinidae Swainson 1827 appears to be a senior name to Riodinidae Grote 1895, the type genus Erycina Fabricius 1807 is a junior homonym of Erycina Lamarck 1805 (a genus of bivalve mollusk). A family-group name cannot be based on a generic name that is a junior homonym (ICZN Article 39), so Swainson's Erycinidae is invalid. The Commission ruled (ICZN opinion 1073, 1977) that the family group name for this taxon should be Riodinidae Grote 1895 (1827), based on the replacement generic name Riodina that was selected by Westwood , even though there are alternative family-group names with priority (e. g., Nemeobiinae Bates ; Mesosemiini Bates 1859). (Bates employed Erycinidae as the family-group name for these subordinate taxa). This is one of the more confusing puzzles in butterfly nomenclature.
Nearctic, Palearctic, Oriental, Ethiopian, Neotropical, Australian, Oceanic Island
Geographic Range description:
World-wide distribution, but occur mostly in the Neotropics.
Egg mass pattern:
Almost nothing about oviposition patterns and clutch sizes is known for riodinids. Rearing records suggest that most females lay single eggs. Some species of Euselasia, Melanis, and Emesis lay clusters of eggs, and some species (Eurybia, Ancyluris, Emesis, Thisbe, Theope, and Nymphidium) show variation in the numbers of eggs they lay - sometimes a single egg, and sometimes multiple (DeVries et al 1994) Many riodinids defend their eggs by laying them in crevices in bark, leaves or off the host plant, so as to be protected from parasitoids. Some riodinids also have evolved protective interactions with ants, and only lay their eggs where the appropriate ant species is found.
Description of egg morphology:
Riodinid eggs are remarkably varied, many are distinct from all other butterfly eggs. Downey and Allyn (1981) put together a terminology of 7 disctinct forms of lycaenid eggs that is also useful in describing riodinid eggs. 1. "echinoid shape" (Emesis tenedia, Synargis phylleus) 2. "fustrum shape" - a cone with the top sliced off (Euselasia; unusual among butterflies) 3. "tiarate" or crown shaped (Symmachia tricolor) 4. Single flattened pie (Eurybia) 5. Two stacked pies (Lasaia) 6. An ornate pastry (Helicopis and Nymphidium) 7. A soccer ball enclosed in a net bag (Thisbe, Juditha, Synargis) Riodinid and lycaenid eggs differ in that riodinids typically do not have plastrons (highly porous areas of the chorion) that are numerous on lycaenid eggs. DeVries, 1997.
Harvey 1987 notes that a character unique to the Riodinidae is the presence of more than two mandibular setae.
Larval body description:
Often onisciform and frequently hairy.
Overall shape and manner of pupation shows great variability in the Riodinidae. Some are round and squat (Euselasia), some blocky and angular (Leucochimona, Mesosemia), some bear lateral spines (Ancyluris, Necyria), some are smoothly elongate (Theope), some are very similar to lycaenid pupae (Chalodeta), some are enclosed in a cocoon (Anteros, Sarota), some are suspended as are Nymphalid pupae (Emesis, Lepricornis). Harvey (1987) documented that the silk girdle passes across A1 in most Riodinidae (and all Pieridae). The exceptions to this are that the silk girdle passes across A2 in members of the Mesosemia, and in the genus Apodemia and some Emesis, the silk girdle passes across the interface of T3 and A1. DeVries (1996) notes that the cremaster of riodinid pupae is often broader than the cremaster in other butterflies. This trait often allows for a quick way to identify pupae in the field. Riodinid butterflies have cryptic pupae. Some riodinid pupae have abdominal stridulatory organis, indicating that they may (like some lycaenid pupae) produce sounds that might function in dissuading predators.
Adult Thorax Morphology
The male forelegs are reduced, with the tarsomeres fused and pretarsi rarely bearing claws. Not used for walking (Robbins 1988). The coxa extends as a spine-like structure to below the articulation point of the trochanter. (From Scoble, 1992)
Many species are brightly colored and wing-shape is diverse.
Life History and Behavior
Larvae of some species within the tribes Eurybiini, Lemoniini, and Nymphidiini are associated with ants. Some caterpillars from the subfamily Euselasiinae are gregarious feeders. Species with semi-gregarious behaviors can be found in the tribes Eurybiini, Riodinini, Emesini, Lemoniini, Nymphidiini (all subfamily Riodininae). DeVries et al 1994.
Life History: Immature Stages
Riodinids usually pupate as solitary individuals. They may pupate in leaf litter, crannies in tree bark, rolled leaves, and some even in ant nests. Some species of Hades, Euselasia, and Emesis do pupate gregariously.
Larval food items include:
Highly diverse diet. Include:
Larval food habits description:
Among all the butterflies, riodinids and lycaenids have the broadest range of food items, including plant leaves and flowers, insects, insect secretions. They also show great diversity in terms of their patterns of host use, ranging from specialist feeders (e.g. THisbe irenea), to generalists which may feed on plants fro more than a dozen families.
Evolution and Systematics
Systematic and taxonomic history
Nomenclature: Although Erycinidae Swainson 1827 appears to be a senior name to Riodinidae Grote 1895, the type genus Erycina Fabricius 1807 is a junior homonym of Erycina Lamarck 1805 (a genus of bivalve mollusk). A family-group name cannot be based on a generic name that is a junior homonym (ICZN Article 39), so Swainson's Erycinidae is invalid. The Commission ruled (ICZN opinion 1073, 1977) that the family group name for this taxon should be Riodinidae Grote 1895 (1827), based on the replacement generic name Riodina that was selected by Westwood , even though there are alternative family-group names with priority (e. g., Nemeobiinae Bates ; Mesosemiini Bates 1859). (Bates employed Erycinidae as the family-group name for these subordinate taxa). This is one of the more confusing puzzles in butterfly nomenclature. The Riodinidae have been included in the Lycaenidae as the subfamily Riodininae by Ehrlich (1958) and by Kristensen (1976).
Discussion of Phylogenetic Relationships
The tree shown is implied by classifications of Harvey (1987), Corbet et al. (1992), Campbell et al. (2000), Hall (2003) and Lamas (2004), and should be viewed as an informal hypothesis in need of corroboration.
Molecular Biology and Genetics
Statistics of barcoding coverage
|Specimen Records:||3,540||Public Records:||2,004|
|Specimens with Sequences:||3,164||Public Species:||152|
|Specimens with Barcodes:||3,016||Public BINs:||145|
|Species With Barcodes:||305|
The Riodinidae (or metalmarks) are a family of butterflies. The common name "metalmarks" refers to the small metallic-looking spots commonly found on their wings. There are approximately 1,000 species of metalmark butterflies in the world. Although mostly neotropical in distribution, the family is represented both in the Nearctic and the Old World.
Like the lycaenids, the males of this family have reduced forelegs while the females have full-sized, fully functional forelegs. The foreleg of males is often reduced and has a uniquely shaped first segment (the coxa) which extends beyond its joint with the second segment, rather than meeting it flush. They have a unique venation on the hindwing: the costa of the hind wing is thickened out to the humeral angle and the humeral vein is short.
Taxonomy and systematics
Riodinidae is currently treated as a distinct family within the superfamily Papilionoidea, but in the past they were held to be the subfamily Riodininae of the Lycaenidae. Earlier, they were considered to be part of the now defunct family Erycinidae, whose species are divided between this family and the subfamily Libytheinae.
The family Riodinidae consists of three subfamilies. They are:
- Euselasiinae – a handful of genera
- Nemeobiinae – sometimes treated as a tribe, Nemeobiini, but which of the remaining two subfamilies it would belongs is uncertain
- Riodininae – some dozens of genera
Genera of uncertain position
- Hamearis – Duke of Burgundy (Zemerini or distinct subfamily Hamearinae?)
- Taxila – Orange Harlequin
- Tribe Abisarini
- Tribe Nemeobiini
- Tribe Zemerini
The eggs vary in shape but often appear round and flattened. The caterpillars are usually hairy, plump, and are the common overwintering stage. Pupae are hairy and attached with silk to either the host plant or to ground debris or leaf litter. There is no cocoon.
Several genera of Riodinidae have evolved intimate associations with ants, and their larvae are tended and defended by ant associates. This also is the case with several linages of Lycaenidae and contributed to arguments for the uniting the two families. It is now recognized that myrmecophily arose several times among Riodinidae and Lycaenidae clades.
The larvae feed on plants of the families Araceae, Asteraceae, Bromeliaceae, Bombacaceae, Cecropiaceae, Clusiaceae, Dilleniaceae, Euphorbiaceae, Fabaceae, Lecythidaceae, Loranthaceae, Malpighiaceae, Marantaceae, Melastomataceae, Myrtaceae, Orchidaceae, Rubiaceae, Sapindaceae, Zingiberaceae as well as bryophytes and lichens.
- Borror et al. (1989)
- Hall, J.P.W. (2004b)
- See Savela (2007) for references.
- DeVries (2001)
- Borror, Donald J.; Triplehorn, Charles A. & Johnson, Norman F. (1989): An introduction to the study of insects (6th ed.). Philadelphia: Saunders College Pub. ISBN 0-03-025397-7.
- DeVries, P.J. (2001): [Riodinidae]. In Levin, S.A. (ed.): Encyclopaedia of Biodiversity. Academic Press.
- Hall, J.P.W. (2004b): Metalmark Butterflies (Lepidoptera: Riodinidae), pp. 1383–1386. In J.L. Capinera (ed.) Encyclopedia of Entomology, Vol. 2. (PDF)
- Savela, Markku (2007): Markku Savela's Lepidoptera and some other life forms: Riodinidae. Version of 2007-AUG-07. Retrieved 2007-SEP-09.
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- Pelham, Jonathan Catalogue of the Butterflies of the United States and Canada (2008)
- Pyle, Robert Michael The Butterflies of Cascadia (2002)