Leptomyrmex niger

Leptomyrmex niger
Leptomyrmex niger
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Dolichoderinae
Tribe:	Leptomyrmecini
Genus:	Leptomyrmex
Species:	L. niger
Binomial name
Leptomyrmex niger Emery, 1900 Specimen labels
Synonyms
Leptomyrmex lugubris Wheeler, W.M., 1934

Collected from rainforest. Nesting habits are unknown.

At a Glance

• Replete Workers

Identification

L. niger is one of three unicolorous black species found in New Guinea. Lacking dense pubescence, it is unlikely to be confused with the stout and hairy Leptomyrmex flavitarsus. Superficially, L. niger resembles Leptomyrmex melanoticus, but can be distinguished by its lack of a narrow and conical ‘neck’ and relatively stout head (CI 0.57–0.69 vs 0.53–0.56 in L. melanoticus). The elongate eyes (EL 0.38–0.47 mm) are generally larger than the small, round eyes of L. melanoticus (EL 0.36–0.39). Antennal scapes of L. niger are relatively shorter (SI 2.96–3.89) than those of L. melanoticus (SI 4.02–4.05). Additionally, the junction of the dorsal and declivitous faces of the propodeum is distinctly angular, unlike in L. melanoticus where the dorsal face gradually rounds into the declivitous face. (Lucky and Ward 2010)

Keys including this Species

• Key to New Guinean Leptomyrmex Species

Distribution

Latitudinal Distribution Pattern

Latitudinal Range: -5.083330154° to -9.199999809°.

North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

• Source: AntMaps

Distribution based on Regional Taxon Lists

Indo-Australian Region: New Guinea (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

Queens have yet to be collected.

Worker

Images from AntWeb

Worker. Specimen code casent0127002. Photographer Andrea Lucky, uploaded by California Academy of Sciences.	Owned by PSWC, Philip S. Ward Collection.

Images from AntWeb

Worker. Specimen code casent0012085. Photographer Andrea Lucky, uploaded by California Academy of Sciences.	Owned by PSWC, Philip S. Ward Collection.

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.

• niger. Leptomyrmex niger Emery, 1900c: 333, pl. 8, figs. 3, 4 (w.) NEW GUINEA. Karavaiev, 1926d: 430 (m.). Senior synonym of lugubris: Lucky & Ward, 2010: 40. See also: Wheeler, W.M. 1934c: 109.
• lugubris. Leptomyrmex lugubris Wheeler, W.M. 1934c: 110, fig. 14 (w.) NEW GUINEA. Junior synonym of niger: Lucky & Ward, 2010: 40.

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) – measurements (n = 11) HL 1.76–1.89, HW 1.01–1.25, MFC 0.18–0.33, IOD 0.55–0.62, SL 3.62–3.94, EL 0.38–0.47, WL 3.16–3.58, PW 0.90–1.00, DPW 0.31–0.39, HTL 3.25–4.45, HTWmin 0.09–0.14, HTWmax 0.16–0.23, CI 0.57–0.69, SI 2.96–3.89, OI 0.11–0.14, HTC 0.50–0.81.

Small and slender (HL 1.76–1.89; HW 1.01–1.25) with head, excluding mandibles, less than twice as long as broad (CI 0.57–0.69) and widest just posterior to eyes. Sides of head straight and subparallel, tapering anteriorly to slightly concave genae, rounded posterior to eyes, gently tapering to flat postocular margin. Approximately 20 teeth and denticles interspersed on masticatory margin of mandible. Anterior clypeal margin flat to slightly concave. Eyes positioned slightly posterior to midline of head, relatively large, oblong, hairless and reaching lateral margins of head. Antennae slender and slightly compressed. Scapes surpassing posterior margin of head by nearly 3/5 their length.

Pronotum with anterior portion dorsoventrally flattened, posterior portion domed. Propodeum with a longitudinal impression, dorsal face 1.5 times length of declivitous face, faces meeting at a distinct (not broad and rounded) angle. Dorsal face of propodeum concave in profile at anterior end. Petiole nearly twice as long as broad, node triangular in profile. Dorsal surface of node with longitudinal impression, anterior face of node much shorter and more rounded than flat posterior face, the two meeting at a rounded angle. Ventral surface flat to weakly concave.Gaster elongate-elliptical. Legs very slender, compressed.

Surface very finely shagreened and shining. Mandibles shining with a row of coarse punctures along margin. Pubescence yellow, mostly limited to head and gaster. Pilosity confined to clypeus, venter and gaster with irregular row of ~4 dark bristles on hind tibiae. Generally black throughout, but portions of mandibles, tarsi, joints and antennal funiculus pale yellow.

Male

Lucky and Ward (2010) – measurements (n = 2) HL 1.52–1.65, HW 1.06–1.10, SL 0.39–0.41, EL 0.63–0.68, HTL 4.80–5.14, CI 0.64–0.72, SI 0.35–0.39, SI2 1.00–1.24.

Type Material

Lucky and Ward (2010):

Syntypes, 2 workers, Papua New Guinea, "New Guinea" [German New Guinea] (Biró) Museo Civico di Storia Naturale, Genoa. One syntype here designated lectotype (CASENT0127396, top specimen).

L. lugubris Syntypes, 2 workers, Papua New Guinea, Morobe: Biolowat (Stevens) Museum of Comparative Zoology

References

• Cantone S. 2017. Winged Ants, The Male, Dichotomous key to genera of winged male ants in the World, Behavioral ecology of mating flight (self-published).
• Casadei-Ferreira, A., Fischer, G., Economo, E.P. 2020. Evidence for a thoracic crop in the workers of some Neotropical Pheidole species (Formicidae: Myrmicinae). Arthropod Structure, Development 59, 100977 (doi:10.1016/J.ASD.2020.100977).
• Emery, C. 1900b. Formicidarum species novae vel minus cognitae in collectione Musaei Nationalis Hungarici quas in Nova-Guinea, colonia germanica, collegit L. Biró. Publicatio secunda. Természetr. Füz. 23: 310-338 (page 333, pl. 8, figs. 3, 4 worker described)
• Karavaiev, V. 1926d. Ameisen aus dem Indo-Australischen Gebiet. Treubia 8: 413-445 (page 430, male described)
• Lucky, A. & Ward, P.S. 2010. Taxonomic revision of the ant genus Leptomyrmex Mayr. Zootaxa 2688: 1-67. PDF
• 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
• 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 109, see also)

References based on Global Ant Biodiversity Informatics

• CSIRO Collection
• Donisthorpe H. 1947. Ants from New Guinea, including new species and a new genus. Annals and Magazine of Natural History (11)13: 577-595.
• Emery C. 1900. Formicidarum species novae vel minus cognitae in collectione Musaei Nationalis Hungarici quas in Nova-Guinea, colonia germanica, collegit L. Biró. Publicatio secunda. Természetrajzi Füzetek 23: 310-338.
• Emery C. 1911. Formicidae. Résultats de l'expédition scientifique néerlandaise à la Nouvelle-Guinée en 1907 et 1909 sous les auspices de Dr. H. A. Lorentz. Nova Guin. 9: 249-259
• Emery C. 1913. Hymenoptera. Fam. Formicidae. Subfam. Dolichoderinae. Genera Insectorum 137: 1-50.
• Janda M., G. D. Alpert, M. L. Borowiec, E. P. Economo, P. Klimes, E. Sarnat, and S. O. Shattuck. 2011. Cheklist of ants described and recorded from New Guinea and associated islands. Available on http://www.newguineants.org/. Accessed on 24th Feb. 2011.
• Karavaiev V. 1926. Ameisen aus dem Indo-Australischen Gebiet. Treubia 8: 413-445.
• Lucky A., and P. S. Ward. 2010. Taxonomic revision of the ant genus Leptomyrmex Mayr (Hymenoptera: Formicidae). Zootaxa 2688: 1-67.
• Room P. M. 1975. Diversity and organization of the ground foraging ant faunas of forest, grassland and tree crops in Papua Nez Guinea. Aust. J. Zool. 23: 71-89.
• Room, P.M. 1975. Relative Distributions of Ant Species in Cocoa Plantations in Papua New Guinea Relative Distributions of Ant Species in Cocoa Plantations in Papua New Guinea. Journal of Applied Ecology 12(1):47-61
• Santschi F. 1932. Résultats scientifiques du voyage aux Indes orientales néerlandaises de LL. AA. RR. le Prince et la Princesse Léopold de Belgique. Hymenoptera. Formicidae. Mémoires du Musée Royal d'Histoire Naturelle de Belgique. (2)4: 11-29.
• 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.
• Snelling R. R. 1998. Insect Part 1: The social Hymenoptera. In Mack A. L. (Ed.) A Biological Assessment of the Lakekamu Basin, Papua New Guinea, RAP 9. 189 ppages
• Stitz H. 1911. Australische Ameisen. (Neu-Guinea und Salomons-Inseln, Festland, Neu-Seeland). Sitzungsberichte der Gesellschaft Naturforschender Freunde zu Berlin 1911: 351-381.
• 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.
• Viehmeyer H. 1914. Papuanische Ameisen. Deutsche Entomologische Zeitschrift 1914: 515-535.
• 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.