Leptomyrmex erythrocephalus

Leptomyrmex erythrocephalus
Leptomyrmex erythrocephalus
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Dolichoderinae
Tribe:	Leptomyrmecini
Genus:	Leptomyrmex
Species:	L. erythrocephalus
Binomial name
Leptomyrmex erythrocephalus (Fabricius, 1775) Specimen labels
Synonyms
Leptomyrmex erythrocephalus clarki Wheeler, W.M., 1934 Leptomyrmex erythrocephalus mandibularis Wheeler, W.M., 1915 Leptomyrmex erythrocephalus unctus Wheeler, W.M., 1934 Leptomyrmex froggatti Forel, 1910

L. erythrocephalus has been recorded in wet sclerophyll, dry sclerophyll, rainforest, gallery rainforest and beach scrub. Nests occur in the ground, under rocks, in soil at the base of trees and under or in logs. (Lucky and Ward 2010)

At a Glance

• Ergatoid queen  • Replete Workers

Photo Gallery

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  Leptomyrmex erythrocephalus replete worker in an artificial nest. Repletes store liquid foods and water within their gasters. This adaptation helps the ants better survive in times of drought, when food and water are scarce. Photo by Jordan Dean.

Identification

Lucky and Ward (2010) – In the Sydney region, where L. erythrocephalus is sympatric with Leptomyrmex cnemidatus, the two species can be quite difficult to distinguish, but the following characters will aid in separating them: in L. erythrocephalus, the central portion of clypeus, excluding the anterior margin presents 0–2 black setae (2–4 in L. cnemidatus); if 2 setae are present then these are separated by 0.25 mm or more (< 0.25 mm in L. cnemidatus). Outside of the Sydney region geographic distribution can also help distinguish these species: L. erythrocephalus occurs coastally and inland from Victoria to the Sydney area, but farther north to the Queensland border it inhabits only inland areas (> 100km from the coastline), whereas L. cnemidatus populations remain within 100 km of the coast.

In color pattern L. erythrocephalus resembles Leptomyrmex ruficeps, but the latter is confined to northern Queensland. The rounded postocular margin also helps to distinguish L. erythrocephalus (elongate and constricted in L. ruficeps). L. erythrocephalus may be difficult to distinguish from some individuals of Leptomyrmex wiburdi, which possess the typical L. erythrocephalus color pattern. The large size (HW 1.31–1.47 mm; WL 4.20–4.64 mm; in L. wiburdi HW 1.15–1.33 mm; WL 3.06–3.65 mm), narrower head (CI 0.59–0.62 mm; in L. wiburdi CI 0.66–0.70) and longer scapes (SI 2.87–3.20; in L. wiburdi SI 2.29–2.64) will identify L. erythrocephalus upon close examination.

Identification Keys including this Taxon

• Key to Australian Leptomyrmex Species

Distribution

Latitudinal Distribution Pattern

Latitudinal Range: -12.659692° to -38.06420894°.

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.

Biology

Explore Overview of Leptomyrmex 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

Wheeler (1934) described queens of L. erythrocephalus as ergatoid, just slightly larger than workers.

Worker and ergatoid queen of L. erythrocephalus. From Wheeler 1934.

Images from AntWeb

Neotype of Leptomyrmex erythrocephalus. Worker. Specimen code casent0011746. Photographer Andrea Lucky, uploaded by California Academy of Sciences.	Owned by ANIC, Canberra, Australia.

Worker. Specimen code casent0106077. Photographer Michael Branstetter, uploaded by California Academy of Sciences.	Owned by UCDC, Davis, CA, USA.

Phylogeny

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.

Nomenclature

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

• erythrocephalus. Formica erythrocephala Fabricius, 1775: 391 (w.) AUSTRALIA. Emery, 1891a: 152 (m.); Wheeler, G.C. & Wheeler, J. 1951: 179 (l.); Imai, Crozier & Taylor, 1977: 345 (k.). Combination in Leptomyrmex: Mayr, 1862: 696. Senior synonym of clarki, froggatti, mandibularis, unctus: Lucky & Ward, 2010: 30. See also: Wheeler, W.M. 1915d: 265; Wheeler, W.M. 1934c: 85.
• froggatti. Leptomyrmex froggatti Forel, 1910b: 57 (w.m.) AUSTRALIA. See also: Wheeler, W.M. 1934c: 101. Junior synonym of erythrocephalus: Lucky & Ward, 2010: 30.
• mandibularis. Leptomyrmex erythrocephalus var. mandibularis Wheeler, W.M. 1915d: 268 (w.) AUSTRALIA. Subspecies of erythrocephalus: Wheeler, W.M. 1934c: 87. Junior synonym of erythrocephalus: Lucky & Ward, 2010: 30.
• clarki. Leptomyrmex erythrocephalus subsp. clarki Wheeler, W.M. 1934c: 117 (w.) AUSTRALIA. Junior synonym of erythrocephalus: Lucky & Ward, 2010: 30.
• unctus. Leptomyrmex erythrocephalus subsp. unctus Wheeler, W.M. 1934c: 87 (w.) AUSTRALIA. Junior synonym of erythrocephalus: Lucky & Ward, 2010: 30.

Type Material

• Leptomyrmex erythrocephalus: Holotype, worker, vicinity of Sydney, New South Wales, Australia, Museum of Comparative Zoology.
• Leptomyrmex erythrocephalus: Syntype, 11 workers, Condor Creek, near Canberra, 2400 ft., ACT, Australia, Museum of Comparative Zoology.
• Leptomyrmex erythrocephalus: Syntype, 15 workers, Condor Creek, near Canberra, 2800 ft., ACT, Australia, Museum of Comparative Zoology.
• Leptomyrmex erythrocephalus: Syntype, 2 workers (1 missing gaster), Fletcher, Queensland, Australia, Museum of Comparative Zoology.
• Leptomyrmex erythrocephalus: Syntype, 2 workers, Condor Creek, near Canberra, 2400 ft., ACT, Australia, Museum Victoria, Melbourne.
• Leptomyrmex erythrocephalus: Syntype, 3 workers, Fletcher, Queensland, Australia, Museum Victoria, Melbourne.
• Leptomyrmex erythrocephalus: Syntype, 2 workers, Condor Creek, near Canberra, 2400 ft., ACT, Australia, National Museum of Natural History.
• Leptomyrmex erythrocephalus: Syntype, 2 workers, Condor Creek, near Canberra, 2800 ft., ACT, Australia, National Museum of Natural History.
• Formica erythrocephala: Holotype, worker, Australia (as New Holland), Australia, The Natural History Museum.
• Leptomyrmex froggatti: Syntype, 3 workers, New South Wales (specific locality not given), Australia, Walcher, ANIC32-014974, Australian National Insect Collection.
• Leptomyrmex froggatti: Syntype, 1 worker, New South Wales (specific locality not given), Australia, The Natural History Museum.
• Leptomyrmex froggatti: Syntype, 29 workers, 3 males, New South Wales (specific locality not given), Australia, Musee d'Histoire Naturelle Genève.
• Leptomyrmex froggatti: Syntype, 1 worker, Australia, Australia, Naturhistorisches Museum, Basel.
• Leptomyrmex froggatti: Syntype, 1 worker, New South Wales (specific locality not given), Australia, Oxford University Museum of Natural History.

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

Description

Lucky and Ward (2010) – measurements (n = 10) HL 2.17–2.41, HW 1.31–1.47, MFC 0.27–0.32, IOD 0.78–0.93, SL 3.90–4.29, EL 0.41–0.50, WL 4.20–4.64, PW 1.21–1.44, DPW 0.44–0.56, HTL 4.80–5.38, HTWmin 0.13–0.17, HTWmax 0.27–0.32, CI 0.59–0.62, SI 2.87–3.20, OI 0.09–0.12, HTC 0.42–0.58.

As in Leptomyrmex cnemidatus, but larger on average: HW 1.31–1.47 mm; WL 4.20–4.64 mm (L. cnemidatus HW1.20–1.39 mm; WL 3.79–4.32 mm). Typical color pattern consisting of black body with contrasting rufotestaceous head, antennae and tarsi. In northern half of range (> 100km inland, e.g. Girraween NP) some individuals become variable in coloration, with head black and/or variable amounts of black and rufotestaceous color occuring on mesosoma.

Male

Lucky and Ward (2010) – measurements (n = 9) HL 1.60–1.80, HW 1.10–1.30, SL 0.56–0.64, EL 0.55–0.71, HTL 4.57–5.03, CI 0.65–0.76, SI 0.46–0.55, SI2 1.03–1.20. Emery’s (1891) description of the male of L. erythrocephalus is probably a misidentification, as it does not correspond with known males of this species.

Karyotype

• n = 12 (Australia) (Imai et al., 1977).

References

• Emery, C. 1883. Alcune formiche della Nuova Caledonia. Bull. Soc. Entomol. Ital. 15: 145-151 (page 147, queen described)
• Emery, C. 1891b. Le formiche dell'ambra Siciliana nel Museo Mineralogico dell'Università di Bologna. Mem. R. Accad. Sci. Ist. Bologna (5)1:141-165 (page 152, male described)
• Fabricius, J. C. 1775. Systema entomologiae, sistens insectorum classes, ordines, genera, species adiectis synonymis, locis, descriptionibus, observationibus. Flensburgi et Lipsiae [= Flensburg and Leipzig]: Korte, 832 pp. (page 391, worker described)
• Imai, H. T.; Crozier, R. H.; Taylor, R. W. 1977. Karyotype evolution in Australian ants. Chromosoma (Berl.) 59: 341-393 (page 345, karyotype described)
• Lucky, A. 2011. Molecular phylogeny and biogeography of the spider ants, genus Leptomyrmex Mayr (Hymenoptera: Formicidae). Molecular Phylogenetics and Evolution 59: 281-292.
• Lucky, A. & Ward, P.S. 2010. Taxonomic revision of the ant genus Leptomyrmex Mayr. Zootaxa 2688: 1-67.
• Mayr, G. 1862. Myrmecologische Studien. Verh. K-K. Zool.-Bot. Ges. Wien 12: 649-776 (page 696, Combination in Leptomyrmex)
• Wheeler, G. C.; Wheeler, J. 1951. The ant larvae of the subfamily Dolichoderinae. Proc. Entomol. Soc. Wash. 53: 169-210 (page 179, larva described)
• Wheeler, W. M. 1915e. The Australian honey-ants of the genus Leptomyrmex Mayr. Proc. Am. Acad. Arts Sci. 51: 255-286 (page 265, see also)
• Wheeler, W. M. 1934c. A second revision of the ants of the genus Leptomyrmex Mayr. Bulletin of the Museum of Comparative Zoology 77: 69-118 (page 85, see also)

References based on Global Ant Biodiversity Informatics

• CSIRO Collection
• Emery C. 1913. Hymenoptera. Fam. Formicidae. Subfam. Dolichoderinae. Genera Insectorum 137: 1-50.
• Emery, C.. "Catalogo delle formiche esistenti nelle collezioni del Museo Civico di Genova. Parte terza. Formiche della regione Indo-Malese e dell'Australia." Annali del Museo Civico di Storia Naturale Giacomo Doria (Genova) (2) 4, no. 24 (1887): 209-258.
• Lucky A., and P. S. Ward. 2010. Taxonomic revision of the ant genus Leptomyrmex Mayr (Hymenoptera: Formicidae). Zootaxa 2688: 1-67.
• Miller L. J., and T. R. New. 1997. Mount Piper grasslands: pitfall trapping of ants and interpretation of habitat variability. Memoirs of the Museum of Victoria 56(2): 377-381.
• Shattuck S. O. 1994. Taxonomic catalog of the ant subfamilies Aneuretinae and Dolichoderinae (Hymenoptera: Formicidae). University of California Publications in Entomology 112: i-xix, 1-241.
• Sinclair J. E., and T. R. New. 2004. Pine plantations in south eastern Australia support highly impoverished ant assemblages (Hymenoptera: Formicidae). Journal of Insect Conservation 8: 277-286.
• Stitz H. 1911. Australische Ameisen. (Neu-Guinea und Salomons-Inseln, Festland, Neu-Seeland). Sitzungsberichte der Gesellschaft Naturforschender Freunde zu Berlin 1911: 351-381.
• Taylor R. W., and D. R. Brown. 1985. Formicoidea. Zoological Catalogue of Australia 2: 1-149. 
• Viehmeyer H. 1912. Ameisen aus Deutsch Neuguinea gesammelt von Dr. O. Schlaginhaufen. Nebst einem Verzeichnisse der papuanischen Arten. Abhandlungen und Berichte des Königlichen Zoologischen und Anthropologische-Ethnographischen Museums zu Dresden 14: 1-26.
• Wheeler W. M. 1915. The Australian honey-ants of the genus Leptomyrmex Mayr. Proceedings of the American Academy of Arts and Sciences 51: 255-286.
• Wheeler W. M. 1934. A second revision of the ants of the genus Leptomyrmex Mayr. Bulletin of the Museum of Comparative Zoology 77: 69-118.