N A T U R K U N D L I C H E S   I N F O R M A T I O N S S Y S T E M

Baronia brevicornis Salvin, 1893

(zoological nomenclature: valid name, available)

General information:

Baronia brevicornis Salvin, 1893: 331-332.
Type locality: Western Mexico, Sierra Madre del Sur, near Chilpancingo, 4500 ft.
Type: Holotype : Western Mexico, Sierra Madre del Sur, near Chilpancingo, 4500 ft., leg. O. T. Baron, coll. BMNH, London

Synonyms, misspellings, wrong determinations, etc.:
Baronia brevicornis f. eusemna Dyar, 1912. Unavailable infrasubspecific name.
Baronia brevicornis var. aureomaculata Bryk, 1913. Junior subjective synonym.
Baronia brevicornis f. pallida Kotzsch, 1939. Unavailable infrasubspecific name.
>Baronia brevicornis f. parvisubmarginalis Eisner, 1974. Unavailable infrasubspecific name.
Baronia brevicornis rufodiscalis de la Maza & White, 1987. Junior subjective synonym.

Short-horned Baronia

Habit:

     
without data      
Picture from: wikimedia commons: Geller-Grimm Fritz (creative commons)
Detailed view
     

Description of adults (original description by Salvin 1893): Wingspan 55-65 mm. "Wings brown; fringe between the nervules narrowly white; primaries [forewings] with three arched series of oval ochraceous spots—the first with four spots, one in the cell, the fourth near the inner margin; the second with seven, all beyond the cell, those between the median branches and at the anal angle quite small; the third with four subapical spots; secondaries [hindwings] with the costal two-thirds of the cell and beyond it nearly to the costa yellow ochre; three spots forming a triangle beneath the cell, the longest forming the base below the first median branch, and the smallest (the apex) above the second branch, and a discal row of six spots also yellow ochre. Beneath as above, but paler; the subapical series of spots on the primaries and an additional submarginal row silver; secondaries with all the spots silver, the discal row larger and more elongated, and a submarginal row near the anal angle. Primaries slightly produced, the apex rounded, the outer margin slightly concave; secondaries rounded, neither the apical nor the anal angles prominent, and no trace of a tail.
Female.—Like the male, but larger, the spots near the costa of the primaries whitish, and an additional series of four small yellowochre submarginal spots; secondaries with the yellow-ochre marks much more extensive, and even confluent in places; an additional submarginal row of ochre spots. Beneath with the spots of the apex of the primaries and those of the secondaries silver." The female possesses an abdominal scent organ (Häuser 1992).

Variability: The species is highly variable with respect to number and size of the light markings and the tone of their colouration, which ranges from cream-white to orange-yellow. The females are generally slightly larger than the males, the markings being more yellow-ochreous. They are sometimes distinctly darker than usual (Collins & Morris 1985).

Distribution:

B. brevicornis is endemic to western and south-western Mexico, where it occures in isolated colonies. Records are known from the following states: Jalisco, Oaxaca, Chiapas, Guerrero, Morelos, Puebla, Michoacan, and Colima (Collins & Morris 1985). Pérez (1977) records the vertical distribution from 505 - 1335 m, whereas Salvin (1893) gives the height of the type locality with 4500 ft. (appr. 1500 m a.s.l.).

Biology:

     
Mexico, Cerro Frio (1300 m) El Zapote, in the west of Tilzapotla (Morelos)      
Picture from: www.picasaweb.google.com: Legal L. (creative commons)
Detailed view
     

The species inhabits thickets of deciduous scrub, which are mainly composed of the foodplant of the larva, Acacia cochliacantha. Untill seasonal rainfall, the trees are bare. With the outcome of the first leafes, the butterflies emerge. Soon after, the females lay their eggs, a few only per tree (Vázquez and Pérez 1961, Pérez 1977). The males are territorial, defending invaders from a branch high up in the trees. Eventually, both males and females come down to drink on sandy banks of small streams (Collins & Morris 1985 following de la Maza in litt.). The imagines are on the wing in June and July (Salvin 1893), eventually also early August (Kurz & Kurz 2011). The eggs are parasitized by Trichogrammatidae species. The caterpillars have been observed to be taken by bugs of the family Pentatomidae, but their osmeterium seems to produce quite effective repellents for predators. Adults may be caught by spiders (Argiopidae) or robberflies (Asilidae) (Pérez 1971).

Stages in development:

Larva. The larva is green with a continuous yellow dorsal stripe and white transverse lines on each segment. It bears small black or yellow tubercles. The head may either be black, green or yellow (Igarashi 1979, Pérez 1969, Tyler 1975, Vásquez & Pérez 1967). Like other Papilionidae, it possesses a defensive osmeterium. When disturbed, the larva extrudes its osmeterium and tries to wipe the odorous secret against the aggressor (Eisner et al. 1970). The larvae feed on Acacia cochliacantha, which is a unique choice among Papilionidae (Vázquez and Pérez 1961). For pupation, they come down to the ground and dig themselves into loose soil (Pérez 1977).

Diagnosis:

Within its distribution range, B. brevicornis is unmistakeable.

Phylogeny: B. brevicornis is referred to as a "living fossil". It is the only member of the Baroniinae, which is regarded to be the most primitive group of Papilionoidea. Unusual characters are found in the venation, the short antennae, the presence of an abdominal scent organ in females, but also in the unique choice of the larval foodplant. In some primitive features, B. brevicornis closely resembles the middle eocenic Praepapilio colorado, thus suggesting the origin of Papilionidae to be in North America rather than in south-east Asia (Hancock 1983).

Biochemical performances:

The secretion of the larval osmeterium has been shown to consist mainly of two aliphatic acids, i.e. isobutyric acid and 2-methyl-butyric acid (Eisner et al. 1970).

Worth knowing:

Conservation status: Following the IUCN Red List of Threatened Species (Gimenez Dixon 1996), the species is classified as "Near Threatened (IUCN 2.3)". B. brevicornis is under no immediate threat, but its local occurence makes populations very vulnerable against degredation of the Acacia-thickets, mainly due to the pressure of rapidly growing human population in Mexico (Collins & Morris 1985).

Sources:

Collins, N. M. & M. G. Morris 1985. Threatened Swallowtail Butterflies of the World. The IUCN Red Data Book. 401 pp., 8 pl. - available at: http://www.archive.org/details/threatenedswallo85coll.
Eisner, T., T. E. Pliske, M. Ikeda, D. F. Owen, G. L. Vázquez, R. H. Perez, J. G. Franclemont & J. Meinwald 1970. Defense mechanisms of arthropods. XXVII. Osmeterial secretions of papilionid caterpillars (Baronia, Papilio, Eurytides). Annals of the Entomological Society of America 63: 914-915.
Gimenez Dixon, M. 1996. Baronia brevicornis. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.1. URL: www.iucnredlist.org. [online 28 June 2011].
Hancock, D. L. 1983. Classification of the Papilionidae (Lepidoptera): a phylogenetic approach. Smithersia 2: 1-48.
Häuser, C. L. 1992. A new abdominal scent organ in females of Baronia brevicornis (Lepidoptera: Papilionidae). Zoologischer Anzeiger 229 (1/2):54-62.
Igarashi, S. 1979. Papilionidae and Their Early Stages. Vol 1: 219 pp.. Vol 2: 102 pp. of plates. Kodansho, Tokyo. (In Japanese).
Kurz, M. A. & M. E. Kurz 2000–2011. Naturkundliches Informationssystem. – URL: http://www.nkis.info [online 20 Mai 2011].
Pérez, R. H. 1969. Quetotáxia y morfología de la oruga de Baronia brevicornis Salv. (Lepidoptera Papilionidae Baroniinae). Anales del Instituto de Biología Universidad de México. 40, Ser. Zool. (2): 227-244.
Pérez, R. H. 1971. Algunas consideraciones sobre la población de Baronia brevicornis Salv. (Lepidoptera, Papilionidae, Baroniinae) en la región de Mezcala, Guerrero. Anales del Institute de Biología Universidad de México 42, Ser. Zool. (1): 63-72.
Pérez, R. H. 1977. Distribución geográfica y estructura poblacional de Baronia brevicornis Salv. (Lepidoptera, Papilionidae, Baroniinae) en la República Mexicana. Anales del Insiituto de Biología Universidad de México 48, Ser. Zool. (5): 151-164.
Salvin, O. 1893. Description of a new genus and species of Papilionidae from Mexico. The Transactions of the entomologicla Society of London (IV): 331-332.
Tyler, H. A. 1975. The Swallowtail Butterflies of North America. Naturegraph, California, viii + 192 pp., 16 pl.
Vázquez, G. L. & R. H. Pérez 1961. Observaciones sobre la biologia de Baronia brevicornis Salv. (Lepidoptera: Papilionidae—Baroniinae). Anales del Institute de Biología Universidad de México 32: 295-311.
Vázquez, G. L. & R. H. Pérez 1967. Nuevas observaciones sobre le biología de Baronia brevicornis Salv. Lepidoptera: Papilionidae—Baroniinae. Anales del Instituto de Biología Universidad de México. 37: 195-204.

Publication data:

history:
Kurz Michael: 2011.03.02
Kurz Michael: 2011.06.28
Kurz Michael: 2011.06.29
Kurz Michael: 2011.06.30
Kurz Michael: 2012.07.12
Document reviewed by:
not reviewed: 2014.04.03
Document released by:
Kurz Michael: 2014.04.03

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