Leptomyrmex rothneyi

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Leptomyrmex rothneyi
Leptomyrmex rothneyi
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Dolichoderinae
Genus: Leptomyrmex
Species: L. rothneyi
Binomial name
Leptomyrmex rothneyi
Forel, 1902

Leptomyrmex rothneyi side view

Leptomyrmex rothneyi top view

Specimen labels

Evolutionary Relationships
Leptomyrmex
Neotropical

Leptomyrmex neotropicus (fossil only)



Leptomyrmex relictus



Australasian
Micro-Leptomyrmex

Leptomyrmex burwelli



Leptomyrmex dolichoscapus



Macro-Leptomyrmex


Leptomyrmex mjobergi




Leptomyrmex varians




Leptomyrmex unicolor





Leptomyrmex flavitarsus



Leptomyrmex puberulus





Leptomyrmex darlingtoni




Leptomyrmex fragilis



Leptomyrmex niger











Leptomyrmex erythrocephalus




Leptomyrmex wiburdi




Leptomyrmex cnemidatus




Leptomyrmex nigriventris



Leptomyrmex tibialis









Leptomyrmex geniculatus




Leptomyrmex nigriceps



Leptomyrmex pallens






Leptomyrmex rufithorax




Leptomyrmex rufipes




Leptomyrmex rothneyi



Leptomyrmex ruficeps










Based on Barden et al., 2017. Note only selected Leptomyrmex species are included.

Leptomyrmex rothneyi has been recorded in rainforest, open rainforest, wet sclerophyll, dry sclerophyll and coastal sclerophylL. Nests occur in soil and in or under logs.

Identification

Leptomyrmex rothneyi bears a distinctively narrowed, dorsoventrally flattened constriction at the posterior margin of the head. This necklike structure is also present, but less exaggerated, in the closely related species Leptomyrmex ruficeps and Leptomyrmex rufipes. Coloration can help to distinguish these three: L. rothneyi has a black gaster, a pale orange mesosoma and a dark head which is a mottled brown rather than uniformly black, and often the pronotum and forecoxae are also dark and mottled. In contrast, L. ruficeps is black with a red head, and L. rufipes is pale with a black gaster. L. rothneyi can be distinguished from other Leptomyrmex based on head shape and geographic range; this species occurs only in the southeast corner of Queensland. (Lucky and Ward 2010)

Identification Keys including this Taxon

Distribution

Distribution based on Regional Taxon Lists

Australasian Region: Australia (type locality).

Distribution based on AntMaps

AntMapLegend.png

Distribution based on AntWeb specimens

Check data from AntWeb

Biology

These conspicuous ants are most often encountered individually or as small groups of 2 or 3 foragers on the surface of the ground any time of the day or night. Because of their long legs and thin bodies, they superficially resemble spiders. This is especially true when they are disturbed, as they extend their legs, raise their gasters, and run quickly to escape danger. This has led to their being given the common name "spider ants."

Nests are found in soil or in dead wood, either standing or on the ground, and are often at the base of trees. Colony sizes average a few hundred workers and a single queen. In all but a handful of species, the queen is wingless and worker-like, differing from workers only in being slightly larger and with an enlarged mesosoma. In a few species the queens are fully winged, as they are in most other ants.

When a large source of food is found, workers of Leptomyrmex will return to their nest and recruit additional workers to help utilise the newly found resource. They also use workers as "living storage vessels". These special workers, called repletes, accept liquids from returning foragers who transfer their liquid foods to these selected workers. These special workers continue to accept liquids until their gasters become greatly enlarged and extended. When enlarged, repletes cannot escape the nest and remain inside suspended from the ceiling. They can retain these fluids for extended periods and dispense it on demand when food is in short supply.

Castes

Queens have yet to be collected.

Worker

Colour variation in L. rothneyi.

Nomenclature

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

  • rothneyi. Leptomyrmex varians var. rothneyi Forel, 1902h: 473 (w.) AUSTRALIA. Lucky & Ward, 2010: 48 (m.). Subspecies of varians: Wheeler, W.M. 1934c: 102. Raised to species: Lucky & Ward, 2010: 47.

Type Material

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

Description

Worker

Lucky and Ward (2010) – HL 2.32–2.45, HW 1.29–1.39, MFC 0.30–0.34, IOD 0.70–0.80, SL 4.05–4.36, EL 0.45–0.51, WL 4.30–4.56, PW 1.13–1.19, DPW 0.46–0.51, HTL 5.23–5.67, HTWmin 0.15–0.18, HTWmax 0.21–0.24, CI 0.55–0.57, SI 3.12–3.24, OI 0.13–0.14, HTC 0.64–0.86.

As in Leptomyrmex rufipes: Medium sized species head long and slender, excluding mandibles nearly twice as long as broad. Head widest just anterior to eye level. Sides of head subparallel, narrowing anteriorly, genae slightly concave. Head posterior to eyes narrowing abruptly to dorsoventrally flattened neck-like constriction, projecting posteriorly. Masticatory margin of mandible with 15 to 20 teeth and denticles interspersed. Anterior clypeal margin flat to weakly concave. Eyes positioned posterior to midline of head, relatively elongate, hairless, not surpassing margins of head. Antennae not compressed, scapes surpassing posterior margin of head by 2/3 their length.

Pronotum slender, elongate. Propodeum short, dorsal face slightly impressed tranversely at anterior end, declivitous face short and convex, angle very rounded. Petiole triangular in profile, anterior and posterior faces with median longitudinal impression, dorsum lacking an impression, posterior face longer than anterior face. Ventral surface of petiole nearly flat. Gaster elongate-elliptical. Legs very long and slender, not compressed.

Surface very finely shagreened and somewhat shining throughout. Mandibles with a coarse row of punctures along margin. Pubescence pale, sparse. Hairs minimal, confined to clypeus, venter and gaster. Body coloration dark, generally mottled brown and rufotestaceous, with antennae uniformly dark brown and antennae uniformly rufotestaceous. Femora solid dark brown, with proximal portion pale and coxae mottled dark and light. Tibiae and tarsi pale yellow. Pronotum dark brown, mottled, with the remainder of thorax rufotestaceous with variable brown mottling. Gaster solid black with terminal gastral segments yellow.

Male

Lucky and Ward (2010) – measurements (n = 4) HL 1.76–1.91, HW 1.27–1.33, SL 0.44–0.51, EL 0.65–0.73, HTL 4.49–4.89, CI 0.69–0.72, SI 0.35–0.39, SI2 0.71–0.82.

References

  • Lucky, A. 2011. Molecular phylogeny and biogeography of the spider ants, genus Leptomyrmex Mayr (Hymenoptera: Formicidae). Molecular Phylogenetics and Evolution 59: 281-292. doi:10.1016/j.ympev.2011.03.004
  • Lucky, A. & Ward, P.S. 2010. Taxonomic revision of the ant genus Leptomyrmex Mayr. Zootaxa 2688: 1-67. PDF