Strumigenys alperti

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Strumigenys alperti
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Strumigenys
Species: S. alperti
Binomial name
Strumigenys alperti
Fisher, 2000

Strumigenys alperti casent0003239 profile 1.jpg

Strumigenys alperti casent0003239 dorsal 1.jpg

Specimen labels

Specimens have been found in rainforest and montane rainforest habitats. Collections have been from litter samples, rotten logs, under moss and a pitfall trap.

Identification

Bolton (2000) - A member of the sylvaini complex in the Strumigenys dexis-group. S. alperti is immediately separated from all other members of the group by its unique possession of a transverse band of scale-like hairs, made up of 4-5 rows, on the cephalic dorsum immediately behind the clypeus. S. alperti can be separated from Strumigenys carolinae by the presence of reticulate-punctate sculpture on the promesonotum. S. alperti and carolinae together can be separated from other two members of the sylvaini-complex by the following characters.

S. alperti + carolinae 1 Erect short simple hairs entirely absent from dorsal surfaces of head, alitrunk, waist segments and first gastral tergite.

2 Head dorsolaterally with broad scale-like hairs present.

3 Disc of postpetiole completely surrounded by spongiform tissue in dorsal view.

S. wardi + Strumigenys sylvaini 1 Erect short simple hairs present on dorsal surfaces of head, alitrunk, waist segments and first gastral tergite.

2 Head dorsolaterally without scale-like hairs.

3 Disc of postpetiole not surrounded by spongiform tissue in dorsal view, with anterolateral angles and anterior halves of sides free.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Malagasy Region: Madagascar (type locality).


Distribution based on AntMaps

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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

Nomenclature

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

  • alperti. Strumigenys alperti Fisher, in Bolton, 2000: 639 (w.q.) MADAGASCAR.

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

Description

Worker

Holotype. TL 2.3, H L 0.60, HW 0.52, CI 87, ML 0.14, MI 23, SL 0.27, SI 52, PW 0.31, AL 0.64. Characters of sylvaini-complex. Lateral margin of clypeus, upper scrobe margin, and leading edge of scape each fringed with a row of curved spoon-shaped hairs. Clypeal dorsum with short, anteriorly-directed spatulate hairs. Dorsum of head immediately behind clypeus with a transverse band of scale-like hairs, arranged in 3-4 rows, these hairs similar in size to those fringing the upper scrobe margins. Similar but somewhat more spoon-shaped hairs are also numerous on the dorsal surfaces of the occipital lobes, but they are absent from the median posterodorsal area of the head. There are no standing hairs of any description on the head, alitrunk, postpetiole or first gastral tergite. Eye conspicuous, with 4-5 ommatidia in the longest row. Promesonotal dorsum finely and densely reticulate-punctate, the sculpture fading posteriorly on the propodeal dorsum. Pleurae glassy smooth. Petiole node broader than long in dorsal view, finely reticulate-punctate and with several pairs of posteriorly curved decumbent spatulate hairs. Disc of postpetiole completely surrounded by spongiform tissue; disc with weak longitudinal striolate sculpture on each side of a smooth median strip. Basigastral costulae moderately developed, extending for some distance onto the first gastral tergite.

Paratypes. TL 2.4, HL 0.60-0.61, HW 0.52-0.54, CI 85-89, ML 0.14-0.15, MI 23-25, SL 0.27-0.28, SI 50-54, PW 0.31-0.32, AL 0.66-0.68 (2 measured). As holotype.

The non-paratypic material shows greater size-variation than the type-series: HL 0.60-0.66, HW 0.51-0.58, CI 85-89, ML 0.15-0.17, MI 24-27, but otherwise matches all the critical diagnostic characters.

Type Material

Holotype worker, Madagascar: 17 km. W Andapa, Res. d'Anjanaharibe Sud, 875 m., 2.xi.1994, 14°45'27.9"S, 49°30'36.7"E, primary rainforest, nest in log under moss, 543.12969w (G. D. Alpert) (Museum of Comparative Zoology).

Paratypes. 1 worker and 1 queen (dealate) with same data as holotype but 543.12968q; 1 worker (gaster missing) with same data but 543.13484w (MCZ, The Natural History Museum).

References

  • Fisher, B.L. 2000. The Malagasy fauna of Strumigenys. Pp. 612-696 in: Bolton, B. 2000. The ant tribe Dacetini. Memoirs of the American Entomological Institute. 65:1-1028. (page 639, worker described)