Strumigenys norax

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

Strumigenys norax casent0005613 profile 1.jpg

Strumigenys norax casent0005613 dorsal 1.jpg

Specimen labels

Apparently adaptable in regards to its habitat needs, this species has been found in habitats ranging from a vegetated sandy beach to montane rainforest. Specimens have been collected from litter, rotten wood, and the soil.

Identification

Bolton (2000) - A member of the lysis complex in the Strumigenys arnoldi-group. S. norax and Strumigenys nambao are closely related and can be easily separated from other members of the rogeri-group by the following characters: left and right mandibles each with 2 preapical teeth ; dorsolateral margin of head posteriorly with 2-4 stiff erect hairs that are longer than hairs on leading edge of scape; upper scrobe margin without a projecting lamellate rim above vertical preocular groove on side of head, scrobe weakly marginate to rounded. S. norax can be separated from nambao by the presence of two pairs of erect hairs on the mesonotum while nambao has only one pair of hairs.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Malagasy Region: Madagascar (type locality).

Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Biology

Castes

Worker

Nomenclature

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

  • norax. Strumigenys norax Fisher, in Bolton, 2000: 666 (w.q.) 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 3.0, HL 0.71, HW 0.55, CI 77, ML 0.41, MI 58, SL 0.50, SI 92, PW 0.33, AL 0.78. Characters of lysis-complex. Each mandible with 2 preapical teeth, situated in the apical third; proximal preapical tooth much longer than distal, the latter often reduced to small denticles. Upper scrobe margin without a projecting lamellate rim throughout its length; scrobe weakly marginate to rounded above vertical preocular groove on side of head. Eyes small, convex and plainly visible in full-face view; maximum diameter of eye subequal to maximum width of scape. Scape short, more or less straight, widest in the midsection; hairs on leading edge fine, slightly thickened apically. Cephalic dorsum densely clothed with short curved narrowly clavate ground-pilosity; upper scrobe margin fringed with hairs similar in size and shape as those on the dorsum. Cephalic dorsum with 6 stout standing hairs arranged in a transverse row close to the occipital margin; 3 (occasionally 2 or 4) pairs of stiff erect hairs on dorsolateral margin posteriorly, and 1 pair on vertex . Dorsum of head reticulate-punctate and often with superimposed rugulose sculpture on occipital angles. Pronotal humeral hair stiffly filiform and projecting; humeral angles rounded. Anterior margin of mesonotum with 2 pairs of stout filiform hairs: a pair on anterior margin and a more posteriorly situated pair. Propodeum with one pairs of short, fine, posteriorly curved hairs at anterior base of propodeal spines. Alitrunk dorsum with inconspicuous, short curved fine ground-pilosity. Dorsum of alitrunk in outline convex anteriorly, posterior alitrunk more or less flat to gradually sloping down to declivity. Metanotal groove not or minutely impressed. Anterior mesonotum without a minute carina above the mesothoracic spiracle. Propodeal spines narrowly triangular, almost spiniform; lamella absent from declivity. Pronotal dorsum and sides longitudinally striolate to costulate on a smooth surface, posterior pronotal disc striolate-punctate to rugulose punctate. Remainder of dorsal alitrunk striolate-punctate. Pleurae smooth and shiny with peripheral fine punctulate sculpture. Petiole node in dorsal view about as broad as long. Postpetiole disc longitudinally striolate on a finely punctulate surface. Spongiform appendages of petiole weakly developed; in profile ventral spongiform tissue of petiolar peduncle a narrow irregular strip along the base of the peduncle, depth of strip less than the width of the mandible blade when viewed in profile. Ventral spongiform lobe of postpetiole moderately developed. Basigastral costulae short and distinct. Dorsal surface of petiole with one pair of anteriorly projecting stout hairs; postpetiole and gaster with stout standing hairs which are slightly thickened apically. Colour light yellowish brown to medium brown.

Paratypes. TL 2.8-3.1, HL 0.68-0.72, HW 0.50-0.55, CI 74-77, ML 0.38-0.40, MI 56-58, SL 0.46-0.50, SI 86-94, PW 0.31-0.36, AL 0.71-0.80 (10 measured). As holotype.

Measurements of this material extend the range shown by the type-series: HL 0.65-0.73, HW 0.47-0.53, CI 70-76, ML 0.38-0.41, MI 54-61, SL 0.45-0.49, SI 91-98 (7 measured).

Type Material

Holotype worker, Madagascar: 9.2 km. WSW Befingotra, Res. Anjanaharibe-Sud, 14°45'S 49°28'E, 1200 m., 9.xi.1994, sifted litter (leaf mold rotten wood), montane rainforest #1192 (12)-13 (B. L. Fisher) (MCZ).

Paratypes. 11 workers and 3 queens (deal ate) with same data as holotype but coded (1)-5, (2)-8, (3)-10, (3)-11, (4)-4, (7)-7, (9)-10, (10)-9, (23)-10, (35)-9, (42)-5, (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 666, worker described)