Strumigenys elegantula

Strumigenys elegantula
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Myrmicinae
Tribe:	Attini
Genus:	Strumigenys
Species:	S. elegantula
Binomial name
Strumigenys elegantula (Terayama & Kubota, 1989) Specimen labels

This species was originally found in the leaf litter of an dry evergreen forest. In Hong Kong, this seldom encountered ant was found across a wide range of areas and habitats including managed grasslands, trees along roadsides, shrubland, secondary forest, and Feng Shui woods. Known elevation range in Hong Kong is from 1 to 254 m (Tang et al., 2019).

Identification

Bolton (2000) - A member of the Strumigenys leptothrix-group. Seven species of this group, of which elegantula is one, have the propodeal spines subtended by lamellae (see discussion under Strumigenys leptothrix). Of the seven leptothrix and Strumigenys jacobsoni are quickly distinguished from the other five (Strumigenys alecto, Strumigenys benten, elegantula, Strumigenys formosimonticola, Strumigenys japonica) as the former pair have the cephalic dorsum very densely hairy, with standing hairs arising all over the dorsum from the posterior clypeal margin to the occipital margin. In the other five species standing hairs on the dorsum of the head are much sparser and more limited in distribution, restricted to the zone around the highest point of the vertex to the occipital margin, or absent. Of this complex only alecto and elegantula have long freely projecting hairs on the tibiae; elegantula has the pronotum marginate dorsolaterally and the mesopleuron reticulate-punctate, whereas in alecto the pronotal dorsum rounds into the sides and the mesopleuron is completely smooth.

Keys including this Species

• Key to Strumigenys of China (as Pyramica)
• Key to Strumigenys of East Asia (as Pyramica)

Distribution

Distribution based on Regional Taxon Lists

Oriental Region: Taiwan (type locality), Thailand.
Palaearctic Region: China.

Distribution based on AntMaps

Distribution based on AntWeb specimens

Check data from AntWeb

Biology

Strumigenys were once thought to be rare. The development and increased use of litter sampling methods has led to the discovery of a tremendous diversity of species. Many species are specialized predators (e.g. see Strumigenys membranifera and Strumigenys louisianae). Collembola (springtails) and other tiny soil arthropods are typically favored prey. Species with long linear mandibles employ trap-jaws to sieze their stalked prey (see Dacetine trap-jaws). Larvae feed directly on insect prey brought to them by workers. Trophallaxis is rarely practiced. Most species live in the soil, leaf litter, decaying wood or opportunistically move into inhabitable cavities on or under the soil. Colonies are small, typically less than 100 individuals but in some species many hundreds. Moist warm habitats and micro-habitats are preferred. A few better known tramp and otherwise widely ranging species tolerate drier conditions. Foraging is often in the leaf litter and humus. Workers of many species rarely venture above ground or into exposed, open areas. Individuals are typically small, slow moving and cryptic in coloration. When disturbed individuals freeze and remain motionless. Males are not known for a large majority of species.

Castes

Worker

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  Head view

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  Side view

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  Top view

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  Specimen labels

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Nomenclature

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

• elegantula. Smithistruma elegantula Terayama & Kubota, 1989: 788, figs. 23-27 (w.q.) TAIWAN. Combination in Pyramica: Bolton, 1999: 1673; in Strumigenys: Baroni Urbani & De Andrade, 2007: 119. See also: Bolton, 2000: 431.

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

Description

Worker

Bolton (2000) - HL 0.62-0.66, HW 0.44-0.48, CI 71-73, ML 0.07-0.08, MI 11-13, SL 0.32-0.34, SI 68-74 (6 measured). Cephalic dorsum in profile without standing hairs, or at most with a single sparse transverse row close to the occipital margin. In full-face view laterally projecting straight hairs restricted to the dorsolateral margins of the occipital lobes, where 1-3 may occur on each side. Leading edge of scape with apically directed small hairs only, without freely projecting long simple hairs. Dentition discussed in introduction to group. Pronotum marginate dorsolaterally, the dorsum more or less flat transversely; humeral hair straight and simple, projecting laterally; pronotal dorsum without standing hairs. Mesonotal dorsum with 3 pairs of standing simple hairs. Mesopleuron reticulate-punctate. Propodeal spines subtended by broad lamellae. Dorsal (outer) surfaces of middle and hind tibiae with suberect long straight simple projecting hairs, the longest of them distinctly longer than the maximum tibial width. Femora and basitarsi with similar projecting hairs.

Type Material

Bolton (2000) - Holotype worker, paratype workers and queen, TAIWAN: Nantou Hsien, Puli, 12.vii.1982 (M. Terayama); same locality but 20.viii.1987 (S. Kubota & H. Sakai); Kaohsiung Hsien, Liukuei, 17.viii.1987 (H. Sakai) (The Natural History Museum) [examined].

References

• Baroni Urbani, C. & De Andrade, M.L. 2007. The ant tribe Dacetini: limits and constituent genera, with descriptions of new species. Annali del Museo Civico di Storia Naturale “G. Doria” 99: 1-191.
• Bolton, B. 1999. Ant genera of the tribe Dacetonini (Hymenoptera: Formicidae). J. Nat. Hist. 3 33: 1639-1689 (page 1673, combination in Pyramica)
• Bolton, B. 2000. The ant tribe Dacetini. Memoirs of the American Entomological Institute. 65:1-1028. (page 431, redescription of worker)
• Tang, K.L., Pierce, M.P., Guénard, B. 2019. Review of the genus Strumigenys (Hymenoptera, Formicidae, Myrmicinae) in Hong Kong with the description of three new species and the addition of five native and four introduced species records. ZooKeys 831: 1–48 (DOI 10.3897/zookeys.831.31515).
• Terayama, M.; Kubota, S. 1989. The ant tribe Dacetini (Hymenoptera, Formicidae) of Taiwan, with descriptions of three new species. Jpn. J. Entomol. 57: 778-792 (page 788, figs. 23-27 worker, queen described)
• Terayama, M.; Lin, C.-C.; Wu, W.-J. 1996. The Taiwanese species of the ant genus Smithistruma (Hymenoptera, Formicidae). Jpn. J. Entomol. 64: 327-339 (page 331, see also)
• Wu, J., Wang, C. 1995. The ants of China. Beijing: China Forestry Publishing House, x + 214 pp. (page 67, catalogue)