Ithomiini | |
---|---|
Pteronomyia apuleia from Bolivia | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
Order: | Lepidoptera |
Family: | Nymphalidae |
Subfamily: | Danainae |
Tribe: | Ithomiini Godman & Salvin, 1879 |
Genera | |
43 genera, see text | |
Diversity | |
c. 370 species |
Ithomiini is a butterfly tribe in the nymphalid subfamily Danainae. It is sometimes referred to as the tribe of clearwing butterflies or glasswing butterflies. Some authors consider the group to be a subfamily (Ithomiinae). These butterflies are exclusively Neotropical, found in humid forests from sea level to 3000 m, from Mexico to Argentina. There are around 370 species in some 40–45 genera.
Ithomiines are unpalatable because their adults seek out and sequester pyrrolizidine alkaloids from plants that they visit, especially composite flowers (Asteraceae) and wilted borages (Boraginaceae). The slow-flying adults are Müllerian mimics of each other as well as of many other Lepidoptera. Henry Walter Bates referred to a "transparency group" of Amazon butterfly species. It was originally with seven species belonging to six different genera. Reginald Punnett suggested 28 species of this peculiar facies are known, though some are excessively rare. The majority are ithomiines, but two species of the Danaine genus Lycorea , the pierine Dismorphia orise the swallow-tail Parides hahneli , and several species of diurnal moths belonging to different families also enter into the combination. Identification of adult ithomiines relies on hindwing venation and male androconial scales (sex brushes located on the hindwing costa).
The group has repeatedly been proposed as biological indicators of ecological conditions or biological diversity within neotropical forests, but individual sites harbor between 10 and 50 species, for the most part, and beta diversity is often great, even over relatively short distances.
Ithomiine larvae feed mostly on Solanaceae host plants. Exceptions are the more basal genera Tithorea , Aeria , and Elzunia that, like Tellervo and some Danainae, feed on Echiteae vines (Apocynaceae, Apocynoideae), as well as Megoleria and Hyposcada that feed on Gesneriaceae.
The local abundance of ithomiine butterflies in the Amazon forest, the lack of observations of predation, and their "peculiar smell" led Henry Walter Bates in 1867 to suggest that these organisms should be chemically defended. This was first experimentally demonstrated in 1889 when Thomas Belt fed ithomiines (that he called "Heliconii") to birds, the spider Nephila , and the white faced monkey Cebus capucinus . The butterflies were consistently rejected, but other insects were eaten. Lincoln P. Brower in 1964 also showed that adults of Ithomia drymo pellucida were rejected by the blue jay Cyanocitta cristata bromia, and Haber showed that nine species of birds also rejected several ithomiine species. Besides, João Vasconcellos-Neto and Thomas M. Lewinsohn demonstrated that the Neotropical orb-weaving spider Nephila clavipes released unharmed 14 species of field-caught ithomiine butterflies. [1]
The source of the protecting chemicals in the bodies of adult ithomiines proved not to be their larval host plants, as was first suggested, but rather in plants visited by the butterflies. Adults of ithomiine, mainly males, visit flowers of some Boraginaceae, ( Tournefortia , Heliotropium ), Asteraceae (mostly in the tribe Eupatorieae, and rarely on Senecio species), Apocynaceae (Prestonia, belonging to the tribe Echiteae) and Orchidaceae (Epidendrum paniculatum). Dead or withered plants are also visited and, when feeding on these plants, the butterflies scratch the tissues with their legs and suck the oozing sap. These plants are known to contain pyrrolizidine alkaloids, indicating their role as chemical sources for sequestration. Other butterfly and moth species that sequester pyrrolizidine alkaloids (Danainae, Ctenuchidae, and Arctiidae) also visit similar sources. The first demonstration that pyrrolizidine alkaloids were involved in the chemical defense of insects was given by Thomas Eisner, who showed that the spiders Nephila and Argiope rejected adults of the arctiid moth Utetheisa ornatrix that contain pyrrolizidine alkaloids from their larval host plant, Crotalaria (Fabaceae: Crotalarieae). Eisner's best-selling popular science book For Love of Insects tells the story of this exciting discovery.
The subtribes in the Ithomiini help to organize the 43 recognized genera, but this group is the subject of ongoing molecular, phylogenetic and morphological research, and the classification presented below will no doubt be refined in the near future.
The sister group to the tribe Ithomiini is either the small tribe Tellervini (containing the single Australasian genus Tellervo ) or the larger tribe Danaini. The relationships of the three tribes in the subfamily Danainae are still unclear.
Tribe IthomiiniGodman & Salvin, 1879
Danainae is a subfamily of the family Nymphalidae, the brush-footed butterflies. It includes the Daniadae, or milkweed butterflies, who lay their eggs on various milkweeds on which their larvae (caterpillars) feed, as well as the clearwing butterflies (Ithomiini), and the tellervini.
The Heliconiinae, commonly called heliconians or longwings, are a subfamily of the brush-footed butterflies. They can be divided into 45–50 genera and were sometimes treated as a separate family Heliconiidae within the Papilionoidea. The colouration is predominantly reddish and black, and though of varying wing shape, the forewings are always elongated tipwards, hence the common name.
Coliadinae, the sulphurs or yellows, are a subfamily of butterflies with about 300 described species.
The Satyrini is one of the tribes of the subfamily Satyrinae. It includes about 2200 species and is therefore the largest tribe in the subfamily which comprises 2500 species.
Biblidinae is a subfamily of nymphalid butterflies that includes the tropical brushfoots. This subfamily was sometimes merged within the Limenitidinae, but they are now recognized as quite distinct lineages. In older literature, this subfamily is sometimes called Eurytelinae.
Danaus, commonly called tigers, milkweeds, monarchs, wanderers, and queens, is a genus of butterflies in the tiger butterfly tribe. They are found worldwide, including North America, South America, Africa, Asia, Indonesia and Australia. For other tigers see the genus, Parantica.
Greta is a genus of clearwing (ithomiine) butterflies, named by Arthur Francis Hemming in 1934. They are in the brush-footed butterfly family, Nymphalidae, and are found in Central America, South America, and the Caribbean.
Tellervini is a tribe of danaid butterflies with only the one genus Tellervo, with six widely distributed species found in the Australasian realm and the Indomalayan realm. The taxon is apparently monophyletic, but its relationship with the other two danaid tribes is yet uncertain. The phylogeography of the group is also a challenge to those who hold to a Cenozoic origin of the butterflies.
Chlosyne is a genus of butterflies from North and South America in the family Nymphalidae.
Melinaea menophilus, the Hewitson's tiger or Hewitson's tiger-wing, is a species of butterfly of the family Nymphalidae. It is found throughout the Amazonian region.
Episcada is a genus of clearwing (ithomiine) butterflies, named by Frederick DuCane Godman and Osbert Salvin in 1879. They are in the brush-footed butterfly family, Nymphalidae.
Oleria is a genus of clearwing (ithomiine) butterflies, named by Jacob Hübner in 1816. They are in the brush-footed butterfly family, Nymphalidae.
Hypoleria is a genus of clearwing (ithomiine) butterflies, named by Frederick DuCane Godman and Osbert Salvin in 1879. They are in the brush-footed butterfly family, Nymphalidae.
Ithomia is a genus of clearwing (ithomiine) butterflies, named by Jacob Hübner in 1816. They are in the brush-footed butterfly family, Nymphalidae.
Hypothyris is a genus of clearwing (ithomiine) butterflies, named by Jacob Hübner in 1821. They are in the brush-footed butterfly family, Nymphalidae.
Tithorea harmonia, the Harmonia tiger-wing or Harmonia tiger, is a species of butterfly belonging to the family Nymphalidae.
Godyris zavaleta, the Zavaleta glasswing, is a species of butterfly of the family Nymphalidae. It is found from Costa Rica to southern Peru. The habitat consists of lowland and mid-elevation rainforests at altitudes up to 900 meters.
Pteronymia is a genus of clearwing (ithomiine) butterflies, named by Arthur Gardiner Butler and Herbert Druce in 1872. They are in the brush-footed butterfly family, Nymphalidae.
Thyridia is a monotypic genus of clearwing (ithomiine) butterflies, named by Jacob Hübner in 1816. Its only species is Thyridia psidii, the Melantho tigerwing or clapping ticlear. It is in the brush-footed butterfly family, Nymphalidae and is found in the Neotropical zone.