Strumigenys ection

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

Known from the holotype worker, collected in a montane-rainforest litter sample.

Identification

Bolton (2000) - A member of the sphera complex in the Strumigenys arnoldi-group. S. ection is easily isolated from other members of the sphera-complex by the presence of 2 pairs of erect hairs on the mesonotum.

Keys including this Species

Key to Malagasy Strumigenys

Distribution

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

Nomenclature

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

ection. Strumigenys ection Fisher, in Bolton, 2000: 659 (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 0.97, HW 0.82, CI 85, ML 0.50, MI 52, SL 0.67, SI 82, PW 0.44, AL 0.96. Characters of sphera-complex. Each mandible with 1 preapical tooth, situated in the apical third of the length. Upper scrobe margin not bordered by a projecting laminar rim throughout its length, eyes clearly visible in full-face view. Eye small, convex, its maximum diameter slightly greater than the maximum width of scape. Scape more or less subcylindrical, narrowed near base, approximately straight; hairs on leading edge narrowly spatulate. Cephalic dorsum densely clothed with curved narrowly spatulate ground-pilosity; upper scrobe margin fringed with hairs that are similar in size and shape as those on the dorsum. Cephalic dorsum with 4 pairs of long stout standing remiform hairs arranged as follows: transverse row of 3 pairs close to the occipital margin and 1 pair of erect hairs on vertex. Dorsum of head reticulate-punctate with superimposed rugulose sculpture. Pronotal humeral hair absent. Promesonotal margin with 2 pairs of stout standing narrowly spatulate hairs, anterior pair located on central dorsum, posterior pair situated on lateral margin. Propodeum with two pairs of short, posteriorly curved narrowly spatulate hairs immediately anterior of propodeal spines. Ground-pilosity on alitrunk dorsum as on head but sparser. Dorsum of alitrunk in outline convex anteriorly, posterior mesonotum sharply depressed, propodeum more or less flat. Metanotal groove represented by a shallow impression. Humeral angles rounded, posterolateral margin of pronotum bluntly marginate and with a small raised welt. Propodeal spines narrowly triangular, margins spongiform, subtended by a narrow lamella dorsally; lamella absent near base. Alitrunk dorsum and sides of pronotum densely reticulate-punctate. Sides of pronotum with striolate sculpture anteriorly. Pleurae mostly smooth and shiny with reticulate-punctate sculpture peripherally. Petiole node in dorsal view approximately as long as broad. Postpetiole dorsum smooth centrally with lateral striolate sculpture. In profile ventral spongiform tissue of petiolar peduncle a broad curtain that is continuous along the base of the peduncle, depth of curtain is equal to or slightly greater than maximum width of eye. Ventral spongiform lobe of postpetiole moderately developed. Basigastral costulae distinct, radiating on both sides of a narrow central clear area. Dorsal surface of petiole, postpetiole, and gaster with stout standing narrowly spatulate hairs. Colour medium brown.

Type Material

Holotype worker, Madagascar: 38 km. S Ambalavao, Res. Andringitra, 22°12'S, 46°58'E, 1680 m., 23.x.1996, sifted litter (leaf mold, rotten wood), montane rainforest, #820 (36)-7 (B. L. Fisher) (Museum of Comparative Zoology).

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 659, 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.