Oxysternon festivum explained

Oxysternon festivum is a species of dung beetle of the scarab beetle family. It is a common, diurnal species from northeastern South America and Trinidad where it mostly inhabits forest.

Taxonomy and nomenclature

Oxysternon festivum was among the first dung beetle species studied by zoologist in the early 18th century. The first illustration of an "exceedingly beautiful shining gold and red, three horned beetle" was published in 1747 by August Johann Rösel von Rosenhof, and a first description was done by Laurens Theodorus Gronovius in 1764, but the names applied were non-binomial and therefore invalid for nomenclatural purposes.[1] [2] [3] It was later re-described by Carl Linnaeus under the name of Scarabaeus festivus, and was subsequently included in most publications regarding exotic insects in the late 18th and early 19th centuries.[4] [5] [6] [7] [8]

O. festivum was once assigned to the genus Sternaspis, but the name was preoccupied and thus invalid. Laporte, writing under the pen name of Le Compte de Castelnau, proposed the genus Oxysternon to include several species of Phaneus-like species with a long, spiniform extension of the anterior angle of the metasternum. O. festivum was later designated as the type species of this genus.[4]

Two color phases were described as aberrations by Olsoufieff in 1924, and formalised as subspecies by Arnaud in 2002, using the names O. festivum nigerrimum for the black form from Trinidad and O. festivum viridanum for the green form of the South American mainland. However, the green form occurs uncommonly but widely together with the typical coppery-red form of the South American mainland, leading later authorities to recognize the former as a morph, not a separate subspecies.

Distribution and habitat

This species largely is restricted to the Guiana Shield and can be found in French Guiana, Guyana, Suriname, Venezuela, eastern Colombia, northeastern Brazil, and Trinidad. The vast majority of its range is north of the Amazon River.

O. festivum mostly lives in tropical humid forests, but may also occur in savanna and can tolerate certain degree of habitat changes.[9] It occurs from near sea level to an altitude of .

Appearance

Adults are long, with average being .[10] The species show sexual polymorphism: Major males are horned and females are hornless, while minor males are hornless and often smaller than major males. Females and minor males differ in details of the head shape, specifically the transverse carina.

O. festivum has a colored upperside and black head and underside; the pronotum is smooth. As most Oxysternon species, it has considerable variation in the color of the upperside. In mainland South America, it is typically metallic coppery-red, sometimes with greenish highlights, but occasionally it can be metallic green or rarely black with reddish tones. On the island of Trinidad, the upperside is entirely black and thus it is considered as a separate subspecies, O. festivum nigerrimum.[11]

Behaviour

O. festivum is attracted to dung, carrion and fruits as food resources, but only commonly feeds and breeds on dung from mammals, less frequently carrion.[10] [12] [13]

It has not been studied in O. festivum, but in related species of dung beetles where it has been studied the distinct male morphotypes are associated with different reproductive tactics: major males fight for females and guard and defend burrows actively, while minor males evade fights and try to sneak to the burrows to mate with females.[14]

Notes and References

  1. Book: Rösel. August Johan. De natuurlyke historie der insecten. 1764–1768. Dutch translation. C. H. Bohn en H. de Wit. Haarlem. 2nd Volume, Part 1, pag. 29–30, Tab. B. Fig. 8. 10.5962/bhl.title.7362., pag. 29
  2. Book: Gronovius. Laurentius Theodorus. Zoophilacium Gronovianum: exhibens animalia quadrupeda, amphibia, pisces, insecta, vermes, mollusca, testacea, et zoophyta. 1781. fasc.1-3 . Lugduni Batavorum:Apud Theodorum Haak et Socium et Samuelem et Johannem Luchtmans. 10.5962/bhl.title.115893., pag. 149
  3. Wheeler. Alwyne C.. The zoophylacium of Laurens Theodore Gronovius . Journal of the Society for the Bibliography of Natural History . 2011. 3. 3. 152–157. 10.3366/jsbnh.1956.3.3.152. 19 June 2016 -->.
  4. Book: Castelnau. M. (Le Comte de). Histoire naturelle des insectes, coléoptères . 1850. Société Bibliophile. Paris, France. Tome deuxieme, Premiere partie. 10.5962/bhl.title.36538., pag. 82
  5. Book: Olivier. Guillaume Antoine. Entomologie, ou, Histoire naturelle des insectes: avec leurs caractères génériques et spécifiques, leur description, leur synonymie, et leur enluminée / Coléoptères. 1789. De l'Imprimerie de Baudoin. Paris, France. 10.5962/bhl.title.61905., pag. 110
  6. Book: Gesellschaft Naturforschende Ärzte. Onomatologia Historiae Naturalis Completa oder vollständiges ..., Volume 6. 1775. Stettinische Handlung. Ulm, Frankfurt und Leipzig. 917. 18 June 2016.
  7. Book: Schoenherr. Carl Johan. Synonymia insectorum, oder: Versuch einer synonymie aller bisher bekannten. Gedruckt bey H. A. Nordström. 1806. 35. 18 June 2016.
  8. Book: Fabricius. Johann Christian. Species insectorum. 1781. Impensis Carol. Ernest. Bohnii. Hamburgi et Kilonii. 10.5962/bhl.title.11658., pag. 23
  9. Ferrer-Paris. José R.. Lozano. Cecilia. Cardozo-Urdaneta. Arlene. Thomas Cabianca. Arianna. Indicative response of Oxysternon festivum Linné (Coleoptera: Scarabaidae) to vegetation condition in the basin of the Orinoco river, Venezuela . Journal of Insect Conservation . 2016 . 20 . 3 . 527–538 . 10.1007/s10841-016-9886-6. 254597915 .
  10. Boilly . O. . Lapèze . J. . Dalens . P.-H. . Giuglaris . J.-L. . Touroult . J. . 2016 . Les Phanaeini de Guyane: liste commentée, clés et iconographie (Coleoptera, Scarabaeidae) . ACOREP-France: Coléoptères de Guyane . X . 86–97.
  11. Edmonds. W.D.. Zidek. J.. Revision of the Neotropical dung beetle genus Oxysternon (Scarabaeidae: Scarabaeinae: Phanaeini) . Folia Heyrovskyana . 2004. 11. 1–58.
  12. Edmonds. W. D.. Comparative skeletal morphology, systematics and evolution of the phanaeine dung beetles (Coleoptera: Scarabaeidae) . University of Kansas Science Bulletin . 1972. 49. 11. 731–874. 17 June 2016.
  13. Silvius. KM. Fragoso. JMV. Pulp handling by vertebrate seed dispersers increases palm seed predation by bruchid beetles in the northern Amazon. Journal of Ecology . 2002. 90. 6. 1024–1032. 10.1046/j.1365-2745.2002.00728.x. 17 June 2016 -->. 86303771 . free. 2002JEcol..90.1024S .
  14. Rowland. JM. Emlen. DJ. Two thresholds, three male forms result in facultative male trimorphism in beetles. Science. 323. 5915. 773–776. 10.1126/science.1167345. 19197062. 2009. 2009Sci...323..773R. 5485816 .