Nesomyrmex larsenae

AntWiki - Where Ant Biologists Share Their Knowledge
Jump to navigation Jump to search
Nesomyrmex larsenae
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Crematogastrini
Genus: Nesomyrmex
Species group: simoni
Species: N. larsenae
Binomial name
Nesomyrmex larsenae
Mbanyana & Robertson, 2008

Nesomyrmex larsenae P.jpg

Nesomyrmex larsenae D.jpg

Two specimens were collected from pitfall traps and one specimen from sweeping vegetation in Succulent Karoo near Nieuwoudtville in the Northern Cape. Probably ground-nesting but sweep sample shows that it does forage in vegetation.

Identification

Mbanyana and Robertson (2008) - A member of the simoni species-group. Among the species without hairs on the propodeum (Nesomyrmex larsenae, Nesomyrmex ruani, Nesomyrmex entabeni and Nesomyrmex nanniae), N. larsenae is distinguished by lacking erect hairs on the promesonotum, and also distinguished by its hump-shaped propodeum and by the brick red colour, with gaster dark brown; the other three species have erect hairs on the promesonotum, the propodeum forms an even convexity (not hump-shaped), and their colour is uniformly medium brown.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Afrotropical Region: South Africa (type locality).

Distribution based on AntMaps

AntMapLegend.png

Distribution based on AntWeb specimens

Check data from AntWeb

Biology

Castes

Nomenclature

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

  • larsenae. Nesomyrmex larsenae Mbanyana & Robertson, 2008: 48, figs. 2m-o (w.) SOUTH AFRICA.

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

Description

Worker

Holotype. HL 0.698, HW 0.529, HW1 0.562, CI 76, SL 0.443, SI 84, PW 0.418, ML 0.861, EL 0.197, EI 37.

Mandibles with fine longitudinal striations. Clypeus predominantly smooth, with weak longitudinal striations. Entire anterior margin of clypeus evenly convex. Eyes with 16 ommatidia in a longest row. Scapes relatively short (SI < 85). With head in dorsal view hind margin convex. With mesosoma in profile, dorsal margins of promesonotum and propodeum each convex, with metanotal groove conspicuously impressed. Propodeum hump-shaped in profile, unarmed, with dorsum rounding evenly into declivity. Metapleural lobes low and rounded. Anterior peduncle long and narrow. Subpetiolar process vestigial, visible as a shallow obtuse angle. Petiolar node in profile massive and nodiform with anterior face angled at about 45° whereas posterior face is nearly vertical. Postpetiole low and rounded. Ventral margin of postpetiole in profile obtusely angled, without distinct process. Dorsum of head weakly shining with faint reticulate ground-sculpture; weakly striated between the eyes and more strongly striated between base of antenna and the eyes. Promesonotal dorsum finely reticulate. Propodeal dorsum with irregular reticulate ground sculpture overlaid by faint irregular transverse striations. Base of declivity with strongly developed transverse striations. Petiolar node and postpetiole with irregular sculpture; transverse striations on peduncle and vestigial transverse striations on petiolar node. Base of first gastral tergite with a ring of short costulae; remainder of the tergite predominantly shiny with weak reticulate pattern. Dorsum of head and mesosoma with appressed white, scattered pubescence, no erect hairs. The venter of head with three straight hairs. Propodeum without hairs. Petiolar node and postpetiole each with a pair of backwardly projecting fine long acute hairs in each. First gastral tergite with scattered, short, decumbent hairs, acute apically; with longer erect hairs along the posterior margin and on the sternite. Colour brick red with gaster dark brown.

Paratypes. HL 0.688–0.718, HW 0.531–0.541, HW1 0.565–0.590, CI 75–77, SL 0.462–0.470, SI 87, PW 0.393–0.423, ML 0.859–0.895, EL 0.194–0.207, EI 36–38 (2 of 2 measured). Same data as holotype.

Type Material

Holotype: South Africa: Northern Cape: west of Driefontein farm, Succulent Karoo 2 site (10.7 km 109° ESE Nieuwoudtville), 31°22.581’S 19°13.507’E, 12–19 October 2000, H.G. Robertson, D. Larsen & R. Adams; NW00-SK2P05, SAM-HYM-C019131. Paratype workers with same data as holotype except NW00-SK2-P04, SAM-HYM-C019130, NW00-SK2-Sweep 228, SAM-HYM-C019132.

Etymology

Named after Dawn Larsen, one of the collectors, who is an Assistant Collections Manager in the entomology collection of the Iziko South African Museum.

References