|Based on Barden et al., 2017. Note only selected Leptomyrmex species are included.|
L. pallens has been recorded from rainforest. Nests occur in soil, under tree roots and under rocks.
L. pallens can be distinguished from the other two New Caledonian Leptomyrmex (Leptomyrmex nigriceps and Leptomyrmex geniculatus) by its coloration. The black gaster contrasts with an otherwise unicolored orange body. This species occurs throughout the main island and on Ile des Pins, and is the most commonly encountered of the three species that occur on New Caledonia. (Lucky and Ward 2010)
Keys including this Species
Distribution based on Regional Taxon Lists
Distribution based on AntMaps
Distribution based on AntWeb specimens
Check data from AntWeb
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.
Queens have yet to be collected.
The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.
- pallens. Leptomyrmex pallens Emery, 1883: 147, fig. (w.) NEW CALEDONIA. André, 1887: 290 (m.). See also: Wheeler, W.M. 1915d: 276; Wheeler, W.M. 1934c: 108; Lucky & Ward, 2010: 44.
Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.
Lucky and Ward (2010) – measurements (n = 10) HL 1.64–1.92, HW 0.92–1.11, MFC 0.19–0.25, IOD 0.54–0.63, SL 3.09–3.61, EL 0.30–0.38, WL 2.94–3.58, PW 0.73–0.93, DPW 0.27–0.39, HTL 3.60–4.09, HTWmin 0.11–0.13, HTWmax 0.14–0.18, CI 0.43–0.46, SI 3.11–3.51, OI 0.10–0.14, HTC 0.66–0.83.
As in Leptomyrmex geniculatus, but femora unicolorous. Entire body rufotestaceous, with black gaster. Head and sometimes pronotum slightly darker yellow than body, terminal abdominal segment pale, contrasting with black gaster.
Lucky and Ward (2010) – HL 1.35, HW 1.00–1.03, SL 0.36–0.37, EL 0.54–0.56, HTL 3.89–4.04, CI 0.74–0.76, SI 0.35–0.37, SI2 0.71–0.76.
Lucky and Ward (2010) - Type material examined: Syntypes, 2 workers, New Caledonia: “N. Caléd.” (Gambey) Museo Civico di Storia Naturale, Genoa
- André, E. 1887. Description de quelques fourmis nouvelles ou imparfaitement connues. Rev. Entomol. (Caen) 6: 280-298 (page 290, male described)
- Emery, C. 1883. Alcune formiche della Nuova Caledonia. Bull. Soc. Entomol. Ital. 15: 145-151 (page 147, fig. worker described)
- 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
- Wheeler, W. M. 1915e. The Australian honey-ants of the genus Leptomyrmex Mayr. Proc. Am. Acad. Arts Sci. 51: 255-286 (page 276, see also)
- Wheeler, W. M. 1934c. A second revision of the ants of the genus Leptomyrmex Mayr. Bull. Mus. Comp. Zool. 77: 69-118 (page 108, see also)