Strumigenys alecto

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

Strumigenys alecto casent0900130 p 1 high.jpg

Strumigenys alecto casent0900130 d 1 high.jpg

Specimen Labels

Nothing is known about the biology of Strumigenys alecto.

Identification

Bolton (2000) - A member of the Strumigenys leptothrix-group. S. alecto is closely related to Strumigenys benten and Strumigenys leptothrix. The last is a much more densely hairy species that has the pronotum weakly marginate dorsolaterally in dorsal view. P. leptothrix also has a sparse row of straight simple hairs projecting from the leading edge of the scape, and in profile numerous elongate standing hairs are seen to arise all over the cephalic dorsum from the level of the posterior clypeal margin to the occipital margin. In alecto straight projecting hairs are absent from the scape and have a restricted distribution on the dorsum of the head. Finally, the hairs that project from the dorsal (outer) surface of the hind tibia are longer than the maximum tibial width in leptothrix, shorter in alecto. The species benten is a close sibling of alecto, currently separated from it by the characters noted under the former name.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Palaearctic Region: Japan (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

Nomenclature

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

  • alecto. Pyramica alecto Bolton, 2000: 429 (w.) JAPAN. Combination in Strumigenys: Baroni Urbani & De Andrade, 2007: 115

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 2.6, HL 0.64, HW 0.45, CI 70, ML 0.09, MI 14, SL 0.31, SI 69, PW 0.28, AL 0.69. With the head in full-face view the dorsolateral margins with sparse, very short, straight laterally projecting hairs; 2-3 project from the upper scrobe margin and 4-6 from the occipital lobe margin, on each side. Leading edge of scape with fine apically-directed narrowly spatulate hairs only, without long simple hairs. Vertex finely and very densely reticulate-punctate. Scattered extremely fine longitudinal rugulae occur on the posterior half of the vertex but they are distinctly secondary to the punctate sculpture. In profile the cephalic dorsum with sparse short standing hairs present from just in front of the highest point of the vertex to the occipital margin, and with a very few dorsolaterally. Eye with 4 ommatidia in the longest row. Pronotum not sharply marginate; on the anterior half the dorsum rounds broadly and evenly into the sides, posteriorly more narrowly rounded or even bluntly angular. Pronotal humeral hair long and straight, directed laterodorsally. Standing hairs on pronotal dorsum sparse, short and stubbly; mesonotum with 3-4 pairs of short erect simple hairs. Waist segments and first gastral tergite with standing hairs present. Pleurae and side of propodeum smooth except for some weak punctulate sculpture above the level of the propodeal spiracle. Propodeum armed with a pair of short triangular teeth that are subtended by lamellae; without triangular or spiniform propodeal lobes at base of declivity. Dorsal (outer) surfaces of middle and hind tibiae with projecting suberect to subdecumbent straight simple hairs that are shorter than the maximum tibial width. Short projecting hairs are also present on the other leg segments. Petiole node in profile with a short, near-vertical anterior face. Lateral spongiform lobe of petiole elongate, extended anteriorly almost to the level of the anterior face of the node. Disc of postpetiole distinctly broader than long in dorsal view, smooth and shining.

Paratype. TL 2.7, HL 0.66, HW 0.46, CI 70, ML 0.09, MI 14, SL 0.32, SI 70, P W 0.30, AL 0.71. As holotype but eye with only 3 ommatidia in the longest row.

Type Material

Holotype worker, Japan: Kyoto, Iwairura, iv.1991 (R. Sonobe) (Museum of Comparative Zoology). Paratype. 1 worker with same data as holotype (The Natural History Museum).

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. 2000. The ant tribe Dacetini. Memoirs of the American Entomological Institute. 65:1-1028. (page 429, worker described)