Strumigenys capitata

AntWiki - Where Ant Biologists Share Their Knowledge
Jump to: navigation, search
Strumigenys capitata
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Strumigenys
Species: S. capitata
Binomial name
Strumigenys capitata
(Smith, F., 1865)

Strumigenys capitata casent0280701 p 1 high.jpg

Strumigenys capitata casent0280701 d 1 high.jpg

Specimen Labels

Specimens have been collected in rainforest from a rotten log.

Identification

Bolton (2000) - A member of the Strumigenys capitata-group. Closely related to Strumigenys pedunculata, separated from it by the characters given in the key and apparently also geographically. The known distribution of capitata includes Seram, Sulawesi and New Guinea, but to date pedunculata has only been recorded from the Malay Peninsula and Philippine Islands, although it most likely also occurs in Borneo. Further collecting may annul this apparent geographical separation. A second closely related species, Strumigenys theia, is distinguished by its possession of at least 3 pairs of standing hairs on the mesonotum and completely sculptured lateral alitrunk, which does not have a smooth shining area on the mesopleuron.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Indo-Australian Region: Indonesia, New Guinea (type locality).

Check distribution from AntMaps.

Distribution based on specimens

Loading map...

The above specimen data are provided by AntWeb. Please see Strumigenys capitata for further details

Biology

Strumigenys were once thought to be rare. The development and increased use of litter sampling methods has led to the discovery of a tremendous diversity of species. Many species are specialized predators (e.g. see Strumigenys membranifera and Strumigenys louisianae). Collembola (springtails) and other tiny soil arthropods are typically favored prey. Species with long linear mandibles employ trap-jaws to sieze their stalked prey (see Dacetine trap-jaws). Larvae feed directly on insect prey brought to them by workers. Trophallaxis is rarely practiced. Most species live in the soil, leaf litter, decaying wood or opportunistically move into inhabitable cavities on or under the soil. Colonies are small, typically less than 100 individuals but in some species many hundreds. Moist warm habitats and micro-habitats are preferred. A few better known tramp and otherwise widely ranging species tolerate drier conditions. Foraging is often in the leaf litter and humus. Workers of many species rarely venture above ground or into exposed, open areas. Individuals are typically small, slow moving and cryptic in coloration. When disturbed individuals freeze and remain motionless. Males are not known for a large majority of species.

Castes

Queen

Nomenclature

The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.

  • capitata. Cephaloxys capitata Smith, F. 1865: 77, pl. 4, fig. 5 (q.) NEW GUINEA. Emery, 1887b: 468 (w.; not m., see Brown, 1953g: 118.) Combination in Strumigenys: Emery, 1887b: 468; in Strumigenys (Cephaloxys): Emery, 1924d: 324; in Smithistruma: Brown, 1948e: 105; in Pyramica: Bolton, 1999: 1673; in Strumigenys: Baroni Urbani & De Andrade, 2007: 116. See also: Donisthorpe, 1948h: 80; Brown, 1953g: 117; Bolton, 2000: 395.

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

Description

Worker

Bolton (2000) - TL 2.6-2.8, HL 0.60-0.66, HW 0.51-0.55, CI 82-87, ML 0.15-0.16, MI 24-26, SL 0.30-0.33, SI 58-60, PW 0.36-0.38, AL 0.66-0.75 (10 measured).

Apicoscrobal hair stout, usually somewhat flattened or weakly remiform apically, never flagellate. Dorsum of the densely reticulate-punctate head with a transverse row of 4 standing hairs close to the occipital margin and with a single pair of similar hairs just in front of the highest point of the vertex. Eye with 4-5 ommatidia in the longest row. Pronotal humeral hair long and stout, usually slightly flattened or weakly remiform. Mesonotum with two pairs of standing hairs, the posterior pair the longest; these hairs weakly remiform to feebly clavate apically. Similar hairs occur on the petiole node (2 pairs), the postpetiole disc (3 pairs) and the first gastral tergite (3-4 transverse rows). Side of alitrunk reticulate-punctate except for the katepisternum which is mostly or entirely smooth and shining. Petiole in profile with the curved dorsal surface of the node at most as long as, usually shorter than, the anterior face of the node. In dorsal view the petiole node reticulate-punctate and distinctly broader than long. Disc of postpetiole finely and densely longitudinally costulate, usually obviously so but only feebly marked in some. In profile the ventral spongiform lobe of the postpetiole is smaller than the exposed area of the disc.

Type Material

Bolton (2000) - Holotype queen, NEW GUINEA (A.R. Wallace) (Oxford University Museum of Natural History) [examined].

Smith Types The following notes on F. Smith type specimens have been provided by Barry Bolton (details):

Cephaloxys capitata

Holotype queen in Oxford University Museum of Natural History. Labelled “N” (= New Guinea).

References

  • Baroni Urbani, C. & De Andrade, M.L. 2007. The ant tribe Dacetini: limits and constituent genera, with descriptions of new species. Annali del Museo Civico di Storia Naturale “G. Doria” 99:1-191.
  • Bolton, B. 1999. Ant genera of the tribe Dacetonini (Hymenoptera: Formicidae). J. Nat. Hist. 3 33: 1639-1689 (page 1673, combination in Pyramica)
  • Bolton, B. 2000. The ant tribe Dacetini. Memoirs of the American Entomological Institute. 65:1-1028. (page 395, fig. 250 redescription of worker)
  • Brown, W. L., Jr. 1948e. A preliminary generic revision of the higher Dacetini (Hymenoptera: Formicidae). Trans. Am. Entomol. Soc. 74: 101-129 (page 105, combination in Smithistruma)
  • Brown, W. L., Jr. 1953g. Revisionary studies in the ant tribe Dacetini. Am. Midl. Nat. 50: 1-137 (page 117, redescription of worker, queen, male)
  • Dalla Torre, K. W. von. 1893. Catalogus Hymenopterorum hucusque descriptorum systematicus et synonymicus. Vol. 7. Formicidae (Heterogyna). Leipzig: W. Engelmann, 289 pp. (page 146, catalogue)
  • Donisthorpe, H. 1932c. On the identity of Smith's types of Formicidae (Hymenoptera) collected by Alfred Russell Wallace in the Malay Archipelago, with descriptions of two new species. Ann. Mag. Nat. Hist. 10(10): 441-476 (page 474, redescription of holotype)
  • Donisthorpe, H. 1948h. A redescription of the types of Strumigenys mandibularis F. Smith, and Cephaloxys capitata F. Smith. Psyche (Camb.) 55: 78-81 (page 80, redescription of holotype)
  • Emery, C. 1887h. Catalogo delle formiche esistenti nelle collezioni del Museo Civico di Genova. Parte terza. Formiche della regione Indo-Malese e dell'Australia (continuazione e fine). [concl.]. Ann. Mus. Civ. Stor. Nat. 25[=(2)(5): 465-473 (page 468, descriptions of worker, putative male)
  • Emery, C. 1897c. Formicidarum species novae vel minus cognitae in collectione Musaei Nationalis Hungarici quas in Nova-Guinea, colonia germanica, collegit L. Biró. Természetr. Füz. 20: 571-599 (page 576, catalogue)
  • Emery, C. 1924f [1922]. Hymenoptera. Fam. Formicidae. Subfam. Myrmicinae. [concl.]. Genera Insectorum 174C: 207-397 (page 324, catalogue)
  • Mann, W. M. 1921. The ants of the Fiji Islands. Bull. Mus. Comp. Zool. 64: 401-499 (page 462, combination in Strumigenys (Cephaloxys))
  • Mayr, G. 1866a. Myrmecologische Beiträge. Sitzungsber. Kais. Akad. Wiss. Wien Math.-Naturwiss. Cl. Abt. I 53: 484-517 (page 517, combination in Strumigenys)
  • Mayr, G. 1887. Südamerikanische Formiciden. Verh. K-K. Zool.-Bot. Ges. Wien 37: 511-632 (page 571, description of worker, putative male)
  • Smith, F. 1865a. Descriptions of new species of hymenopterous insects from the islands of Sumatra, Sula, Gilolo, Salwatty, and New Guinea, collected by Mr. A. R. Wallace. J. Proc. Linn. Soc. Lond. Zool. 8: 61-94 (page 77, pl.4, fig. 5 queen described)