Iridomyrmex longisoma

Iridomyrmex longisoma
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Dolichoderinae
Tribe:	Leptomyrmecini
Genus:	Iridomyrmex
Species:	I. longisoma
Binomial name
Iridomyrmex longisoma Heterick & Shattuck, 2011

Known nests of this species have been made directly into sandy soil, and are identical to those of Iridomyrmex bicknelli. Like the latter ant, I. longisoma seems to favour coastal habitats, including vegetated sand-dunes near the ocean, but is less common. Also, as with I. bicknelli, this is a timorous species.

Identification

Iridomyrmex longisoma superficially resembles Iridomyrmex bicknelli, with which it often occurs. Despite the surface similarities, however, the two ants are probably not closely related: I. longisoma has much longer hind tibiae, hirsute antennal scapes (glabrous in I. bicknelli), an elongate pronotal sclerite, and a broadly rounded occiput (narrowly rounded in I. bicknelli). This species also resembles a small Iridomyrmex mayri, an eastern taxon, but lacks the erect hind tibial setae found in that species and its close relatives.

Keys including this Species

• Key to Iridomyrmex species

Distribution

This ant is only found in south-western Western Australia, and appears to be confined to the coast.

Latitudinal Distribution Pattern

Latitudinal Range: -25.958045° to -35.03°.

North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

• Source: AntMaps

Distribution based on Regional Taxon Lists

Australasian Region: Australia (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.

Nomenclature

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

• longisoma. Iridomyrmex longisoma Heterick & Shattuck, 2011: 96, fig. 46 (w.) AUSTRALIA.

Type Material

• Holotype, worker, Hope Valley, Western Australia, Australia, 31°12′30″S 115°47′30″E, 7 May 2006, B. E. Heterick, ANIC32-053429, Australian National Insect Collection; sclerophyll woodland on white sand.
• Paratype, 2 workers, Hope Valley, Western Australia, Australia, 31°12′30″S 115°47′30″E, 7 May 2006, B. E. Heterick, ANIC32-053429, Australian National Insect Collection; sclerophyll woodland on white sand.
• Paratype, 3 workers, Lancelin, Western Australia, Australia, 30°1′0″S 115°20′0″E, 15 July 2000, M. Jacobs, ANIC32-053430, Australian National Insect Collection; heathland: white sand.
• Paratype, 2 workers, Stirling Ranges, Gold Holes, Western Australia, c. 250m, Australia, 28 October 1969, R. W. Taylor, ANIC32-041840, Australian National Insect Collection.
• Paratype, 2 workers, Stirling Ranges, Gold Holes, Western Australia, c. 250m, Australia, 28 October 1969, R. W. Taylor, ANIC32-041840, The Natural History Museum.
• Paratype, 2 workers, Stirling Ranges, Gold Holes, Western Australia, c. 250m, Australia, 28 October 1969, R. W. Taylor, ANIC32-041840, Museum of Comparative Zoology.

Description

Worker Description. Head. Posterior margin of head strongly convex; erect setae on posterior margin in full- face view set in a row; sides of head straight or weakly convex; erect genal setae present on sides of head in full- face view. Ocelli absent; in full-face view, eyes set at about midpoint of head capsule; in profile, eye set anteriad of head capsule; eye semi-circular. Frontal carinae convex; antennal scape surpassing posterior margin of head by at least 0.5 x its length. Erect setae on scape present and abundant, or present and sparse; prominence on anteromedial clypeal margin present as an indistinct swelling or undulation; mandible elongate triangular with oblique basal margin; long, curved setae on venter of head capsule absent. Mesosoma. Pronotum weakly undulant or almost straight. Erect pronotal setae numerous (12 or more), short and bristly. Mesonotum sinuous, or straight. Erect mesonotal setae numerous (12 or more), short and bristly. Mesothoracic spiracles always inconspicuous; propodeal dorsum smoothly and evenly convex; placement of propodeal spiracle mesad, more than its diameter away from propodeal declivity; propodeal angle weakly present or absent, the confluence of the dorsal and declivitous propodeal faces indicated, if at all, by an undulation. Erect propodeal setae numerous (12 or more), short and bristly. Petiole. Dorsum of node acuminate; node thick, orientated anteriad. Gaster. Non-marginal erect setae of gaster present on first gastral tergite; marginal erect setae of gaster present on first tergite. General characters. Allometric differences between workers of same nest absent. Colour uniformly medium to dark chocolate with very weak yellow- green, bluish and/or purple iridescence. Colour of erect setae light brown.

Measurements. Worker (n = 2)—CI 79–80; EI 29–29; EL 0.23–0.24; EW 0.19–0.20; HFL 1.89–1.99; HL 1.01–1.07; HW 0.81–0.85; ML 1.62–1.73; MTL 1.38–1.47; PpH 0.15–0.20; PpL 0.56–0.61; SI 150–153; SL 1.23– 1.30.

Etymology

Latin: longus—‘long’ plus Greek: soma—‘body’

References

• Heterick, B.E. & Shattuck, S.O. 2011. Revision of the ant genus Iridomyrmex (Hymenoptera: Formicidae). Zootaxa 2845: 1-175.
• Heterick, B.E. 2021. A guide to the ants of Western Australia. Part I: Systematics. Records of the Western Australian Museum, Supplement 86, 1-245 (doi:10.18195/issn.0313-122x.86.2021.001-245).
• Heterick, B.E. 2022. A guide to the ants of Western Australia. Part II: Distribution and biology. Records of the Western Australian Museum, supplement 86: 247-510 (doi:10.18195/issn.0313-122x.86.2022.247-510).

References based on Global Ant Biodiversity Informatics

• Heterick B. E., and S. Shattuck. 2011. Revision of the ant genus Iridomyrmex (Hymenoptera: Formicidae). Zootaxa 2845: 1-174.