Strumigenys alexetrix

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

Strumigenys alexetrix casent0280756 p 1 high.jpg

Strumigenys alexetrix casent0280756 d 1 high.jpg

Specimen Labels

Known from wet sclerophyll and rainforest habitats. Two workers were found the the galleries of a Amblyopone australis nest.

Identification

Bolton (2000) - A member of the smythiesii complex in the Strumigenys godeffroyi-group. Among the close relatives of Strumigenys friedae in the smythiesii-complex only Strumigenys harpyia and alexetrix share the character combination of single laterally projecting flagellate hair on the upper scrobe margin (the apicoscrobal hair) with presence of a pair of erect hairs on the pronotal dorsum in addition to the humeral hairs. S. harpyia is a smaller species with shorter scapes than alexetrix (compare measurements). See also notes under friedae.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Australasian Region: Australia (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.

  • alexetrix. Strumigenys alexetrix Bolton, 2000: 956 (w.) AUSTRALIA.

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 0.66, HW 0.46, CI 70, ML 0.28, MI 42, SL 0.38, SI 83, PW 0.29, AL 0.70. With characters of smythiesii-complex. Apicoscrobal hair flagellate, long and straggly. Cephalic dorsum sharply reticulate-punctate and with a single pair of erect fine hairs, located close to midline near occipital margin (absent in nonparatypic specimens). Eye with less than 20 ommatidia; about 12 in holotype. Pronotal humeral hair flagellate, very long and fine; pronotal dorsum with a pair of equally long erect flagellate hairs and sometimes also with another shorter pair. Mesonotum with 1-2 pairs of erect flagellate hairs, the anterior pair the longest. Pronotal dorsum finely granulate to weakly reticulate-punctulate, a few extremely weak longitudinal rugulae may be present, formed by alignment of punctulae margins. Mesonotal and propodeal dorsa reticulate-punctate. Propodeal declivity with a narrow lamella, its posterior (free) margin concave below propodeal tooth but convex thereafter. Katepisternum entirely reticulate-punctate or with a median patch where the sculpture is superficial or effaced; metapleuron and side of propodeum finely reticulate-punctate everywhere. Dorsum of petiole node finely reticulate-punctate; disc of postpetiole smooth. Hairs on first gastral tergite long and fine, flagellate.

Paratype. HL 0.67, HW 0.46, CI 69, ML 0.28, MI 42, SL 0.38, SI 83.

Dimensions of non-paratypic workers. TL 2.4, HL 0.62-0.63, HW 0.45, CI 71-73, ML 0.27, MI 43-44, SL 0.36, SI 80, PW 0.28, AL 0.66 (2 measured).

Type Material

Holotype worker, Australia: New South Wales, Tallagawda State Forest, nr Captains Flat, wet sclero., 15.x.1975, 2 workers in galleries of Amblyopone australis (B. B. Lowery) (Australian National Insect Collection). [Holotype is top worker of two on pin.] Paratype. 1 worker with same data a s holotype (ANIC). [Lower worker of two on pin.]

References

  • Bolton, B. 2000. The ant tribe Dacetini. Memoirs of the American Entomological Institute. 65:1-1028. (page 956, worker described)