Strumigenys atopogenys

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Strumigenys atopogenys
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Strumigenys
Species: S. atopogenys
Binomial name
Strumigenys atopogenys
(Bolton, 2000)

Pyramica atopogenys casent0103050 profile 1.jpg

Pyramica atopogenys casent0103050 dorsal 1.jpg

Specimen labels

Nothing is known about the biology of Strumigenys atopogenys.

Identification

Bolton (2000) - A member of the Strumigenys extemena-group. Together with Strumigenys carinognatha and Strumigenys tarbosyne this species is isolated within the group by the strange morphology of the basidorsal mandible, as described above and under those two species. The structure is more strongly developed in carinognatha and tarbosyne than in atopogenys as in the first two the basidorsal mandible has a concave area bounded by a raised and acute carina, whereas in atopogenys the same area is flat and bounded by a low blunt ridge. Cephalic standing pilosity is also different. S. tarbosyne has two transverse rows of erect remiform hairs on the head close to the highest point of the vertex and carinognatha has a single pair of erect hairs in this position. In contrast atopogenys is entirely without standing hairs on the head.

Elsewhere in the group mandibular structure falls into two forms. In Strumigenys extemena and Strumigenys deinognatha the masticatory margin of the mandible is considerably elevated above the level of the outer margin so that when the masticatory margins are engaged they form the highest point, from which the oblique dorsal surfaces slope steeply away on each side. The mandibles of the remaining 4 species, Strumigenys acheron, Strumigenys aello, Strumigenys ocypete and Strumigenys podarge, lack these specialisations and in shape are more or less normal for Pyramica although ocypete does have a short straight carina mid-dorsally at the base of each mandible.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Indo-Australian Region: Indonesia (type locality).


Distribution based on AntMaps

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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 Online Catalogue of the Ants of the World.

  • atopogenys. Pyramica atopogenys Bolton, 2000: 417 (w.) INDONESIA (Sumatra). Combination in Strumigenys: Baroni Urbani & De Andrade, 2007: 115

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 0.48, HW 0.42, CI 88, ML 0.16, MI 33, SL 0.24, SI 57, PW 0.27, AL 0.52. Basal half of dorsal surface of mandible flat, the flat area sloping upwards anteriorly to approximately the midlength of the mandible as seen in full-face view, distal to which the dorsum of the mandible commences to curve downward. At the apex of the upward- sloping surface is a low blunt arched ridge that traverses the dorsum from the masticatory margin to close to the outer margin and then extends posteriorly toward the basal-external angle of the mandible. Mandible smooth and shining, the basal tooth the largest. Dorsum of head behind clypeus mostly smooth, not uniformly reticulate-punctate. Leading edge of scape rounded at its broadest point, without a projecting subbasal lobe and without a large anteriorly-directed specialised hair at its point of maximum curvature. Hairs on leading edge of scape microscopic and difficult to see, all curved toward the apex of the scape. Vertex of head with a conspicuous transverse crest across its width, the crest forming the highest point of the vertex. Dorsum of head without standing hairs and without orbicular hairs. Eye of a single ommatidium. Dorsal surfaces of alitrunk and petiole without standing hairs but numerous short erect simple hairs are present on the postpetiole and first gastral tergite. Pronotum flat dorsally, marginate dorsolaterally; mesonotum forming a single separate convexity between pronotum and propodeum. Propodeal teeth absent but the declivity with a broad lamella extending its entire height.

Paratypes. TL 2.0-2.1, HL 0.48-0.53, HW 0.45-0.48, CI 90-91, ML 0.16-0.17, MI 32-33, SL 0.24-0.28, SI 53-56, PW 0.27-0.29, AL 0.52-0.60 (2 measured).

Type Material

Holotype worker, Indonesia: Sumatra, Jambi, W Mt Tujuh Lake, 1400 m., 14.xi.1989, #17 (Agosti, Lobi & Burckhardt) (American Museum of Natural History).

Paratypes. 2 workers with same data as holotype (AMNH, The Natural History Museum).

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. 2000. The ant tribe Dacetini. Memoirs of the American Entomological Institute. 65:1-1028. (page 417, worker described)

References based on Global Ant Biodiversity Informatics

  • Bolton B. 2000. The ant tribe Dacetini. Memoirs of the American Entomological Institute 65: 1-1028.