Strumigenys racabura

AntWiki - Where Ant Biologists Share Their Knowledge
Jump to navigation Jump to search
Strumigenys racabura
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Strumigenys
Species: S. racabura
Binomial name
Strumigenys racabura
Bolton, 2000

Strumigenys racabura casent0900847 p 1 high.jpg

Strumigenys racabura casent0900847 d 1 high.jpg

Specimen Labels

Known from rainforest habitats, specimens have been collected in litter-samples and from rotten logs.

Identification

Bolton (2000) - A member of the mayri complex in the Strumigenys mayri-group. See notes under Strumigenys montu. The sculpture of the postpetiole disc varies considerably in this species, as in Strumigenys mayri. Most individuals have weak punctulate sculpture, generally with a few feeble costulae at least anteriorly. Some from New Guinea have quite strong reticulate-punctate sculpture, almost as strong as the sculpture on the petiole node. Others, especially Australian specimens, tend to have the postpetiole sculpture reduced and faint or even effaced in the centre of the disc.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Australasian Region: Australia.
Indo-Australian Region: New Guinea.

Distribution based on AntMaps

AntMapLegend.png

Distribution based on AntWeb specimens

Check data from AntWeb

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

Nomenclature

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

  • racabura. Strumigenys racabura Bolton, 2000: 890 (w.) NEW GUINEA.

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

Description

Worker

Holotype. TL 2.0, HL 0.54, HW 0.36, CI 67, ML 0.23, MI 43, SL 0.34, SI 94, PW 0.23, AL 0.52. Characters of the mayri-complex. Preapical tooth spiniform, equal to or slightly longer than maximum width of mandible. Cephalic dorsum with 4-6 erect hairs along the occipital margin, the pair nearest the midline usually curved or weakly sinuate; a similar pair present at level of highest point of vertex. Preocular notch present (generally somewhat deeper and more incised in Australian than in New Guinean material); ventral surface of head with a broad shallow preocular transverse impression posterior to the narrowly and deeply incised postbuccal groove. Pronotal humeral hair flagellate, pronotum otherwise without erect hairs; mesonotum with one pair of erect flagellate hairs. Dorsal alitrunk reticulate-punctate. Dorsal surfaces of waist segments and first gastral tergite with flagellate hairs. Katepisternum smooth, metapleuron with a smooth patch anteriorly; posterior to this the side usually faintly reticulate-punctate but a few specimens with side mostly smooth. Propodeum armed with a pair of short straight spines, elevated at about 45°, not markedly upcurved, the length of one of which is equal to or slightly greater than distance separating their bases. Dorsal (outer) surface of hind basitarsus with 1-2 long erect flagellate hairs. Petiole in profile with anterior face of node shorter than length of dorsum, in dorsal view petiole node as broad as long or slightly broader than long. Disc of postpetiole superficially sculptured with fine punctulae or costulae (almost smooth in Australian specimens), usually not as densely sculptured as dorsum of petiole node. In dorsal view basigastral costulae about as long as disc of postpetiole.

Paratypes. TL 2.0, HL 0.56-0.57, HW 0.38, CI 67-68, ML 0.24, MI 42-43, SL 0.34-0.35, SI 89-92, PW 0.23, AL 0.56 (2 measured).

Dimensions of non-paratypic workers. HL 0.55-0.60, HW 0.37-0.41, CI 65-71, ML 0.24-0.26, MI 42-46, SL 0.34-0.36, SI 87-94 (15 measured).

Type Material

Holotype worker, Papua New Guinea: Ambunti, 4.13°S, 142.49°E, 50 m., 2.vii.1980, ex rotten log, lowland rainforerst, #4651 (P. S. Ward) (The Natural History Museum). Paratypes. 2 workers with same data as holotype (University of California, Davis).

  • Holotype, worker, Ambunti, Papua New Guinea, The Natural History Museum.
  • Paratype, 2 workers, Ambunti, Papua New Guinea, Univ. of California (Davis).

References

  • Bolton, B. 2000. The ant tribe Dacetini. Memoirs of the American Entomological Institute. 65:1-1028. (page 890, worker described)