Strumigenys apios

Strumigenys apios
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Myrmicinae
Tribe:	Attini
Genus:	Strumigenys
Species:	S. apios
Binomial name
	Strumigenys apios; Fisher, 2000 Specimen labels

Known from rainforest habitats and most commonly collected from litter samples.

Identification

Bolton (2000) - A member of the Strumigenys apios-group. The single specimen from Andasibe is slightly larger and narrower. It has symmetric mandibles with both apical forks of 3 stout spiniform teeth, without preapical teeth or denticles; the sides of its alitrunk have more extensive reticulate-punctate sculpture. Additional collections will be necessary to determine if this specimen represent a sibling species

S. apios is distinguished from its close relative Strumigenys agra by its smaller size, and yellowish brown colour.

Keys including this Species

Key to Malagasy Strumigenys

Distribution

Latitudinal Distribution Pattern

Latitudinal Range: -14.022° to -14.75°.


North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

Source: AntMaps

Distribution based on Regional Taxon Lists

Malagasy Region: Madagascar (type locality).

Distribution based on AntMaps

Distribution based on AntWeb specimens

Check data from AntWeb

Countries Occupied

Number of countries occupied by this species based on AntWiki Regional Taxon Lists. In general, fewer countries occupied indicates a narrower range, while more countries indicates a more widespread species.

Estimated Abundance

Relative abundance based on number of AntMaps records per species (this species within the purple bar). Fewer records (to the left) indicates a less abundant/encountered species while more records (to the right) indicates more abundant/encountered species.

Biology

Explore Overview of Strumigenys 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.

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Castes

Images from AntWeb


Paratype of Strumigenys apios. Worker. Specimen code casent0005488. Photographer April Nobile, uploaded by California Academy of Sciences.	Owned by CAS, San Francisco, CA, USA.


Paratype of Strumigenys apios. Worker. Specimen code casent0005489. Photographer April Nobile, uploaded by California Academy of Sciences.	Owned by CAS, San Francisco, CA, USA.

Nomenclature

The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

apios. Strumigenys apios Fisher, in Bolton, 2000: 626 (w.) MADAGASCAR.

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 4.0, HL 1.02, HW 0.60, CI 59, ML 0.59, MI 58, SL 0.80, SI 133, PW 0.36, AL 1.08. Right mandible with apicoventral tooth the shortest of the 3 teeth of the apical fork; preapical dentition absent. Left mandible with stoutly spiniform apicodorsal and apicomedian teeth, the apicoventral tooth much smaller, and smaller than its counterpart on the right mandible; a small preapical tooth or denticle present close to apicodorsal tooth. In full-face view the short upper scrobe margin rounds cleanly into the long margin of the occipital lobe without trace of an angle, the two together forming a single evenly curved surface. Dorsum of head evenly rounded into side behind level of eye. Maximum diameter of eye distinctly greater than the maximum width of the scape. Scape long, the leading edge with a row of slender spatulate hairs. Cephalic dorsum with appressed clavate to spoon-shaped ground-pilosity; dorsolateral margin of head without a row of hairs. Cephalic dorsum with 4 simple standing hairs arranged in a transverse row close to the occipital margin. Dorsum of alitrunk without standing hairs. Ground-pilosity on alitrunk sparse. Posterior portion of mesonotum shallowly depressed below level of pronotum; propodeal dorsum gently sloping to declivity. Propodeal teeth long, slender and curved anterolaterally; lamella absent from declivity. Alitrunk dorsum reticulate-punctate. Petiole node reticulate-punctate and much longer than broad. Postpetiole disc reticulate-punctate. Spongiform appendages of petiole absent. Lateral and ventral spongiform lobes of postpetiole vestigial. Basigastral costulae fine and superficial; gaster smooth and shiny when clean. Dorsal surface of postpetiole with a pair of posteriorly projecting simple hairs, and posterior margin of gastral segments with standing hairs which are simple or very slightly thickened apically. Colour yellowish brown.

Paratypes. TL 4.0-4.5, HL 1.01-1.13, HW 0.64-0.70, CI 62-64, ML 0.59-0.63, MI 56-62, SL 0.78-0.84, SI 119-129, PW 0.36-0.41, AL 1.07-1.19. As holotype.

Measurements of non-paratypic material extends the range shown by the type-series: HL 0.99-1.17, HW 0.59-0.65, CI 55-62, ML 0.58-0.73, MI 59-62, SL 0.79-0.89, SI 128-138 (3 measured).

Type Material

Holotype worker, Madagascar: 11.0 km. WSW Befingotra, Res. Anjanaharibe-Sud, 14°45'S, 49°27'E, 1565 m., 16.xi.1994, sifted litter (leaf mold, rotten wood), montane rainforest #1232 (28)-4. (B. L. Fisher) (Museum of Comparative Zoology).

Paratypes. 3 workers with same data as holotype, 2 workers with same data as holotype but coded (49)-3 (The Natural History Museum, South African Museum).

References

Fisher, B.L. 2000. The Malagasy fauna of Strumigenys. Pp. 612-696 in: Bolton, B. 2000. The ant tribe Dacetini. Memoirs of the American Entomological Institute. 65:1-1028. (page 626, worker described)

References based on Global Ant Biodiversity Informatics

Bolton, B. 2000. The Ant Tribe Dacetini. Memoirs of the American Entomological Institute 65
Fisher B. L. 2003. Formicidae, ants. Pp. 811-819 in: Goodman, S. M.; Benstead, J. P. (eds.) 2003. The natural history of Madagascar. Chicago: University of Chicago Press, xxi + 1709 pp.
Fisher, B. 2002. Ant diversity patterns along an elevational gradient in the Reserve Speciale de Manongarivo, Madagascar. in Gautier, L. and S.M. Goodman, editors, Inventaire Florestique et Faunistique de la Reserve Speciale de Manongarivo (NW Madagascar)