Strumigenys semirex

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

Known from the type material, a collection from a rainforest litter-sample.


Bolton (2000) – A member of the emdeni complex in the Strumigenys horvathi-group. See Strumigenys emdeni.

Keys including this Species


Distribution based on Regional Taxon Lists

Australasian Region: Australia (type locality).

Distribution based on AntMaps


Distribution based on AntWeb specimens

Check data from AntWeb


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.



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

  • semirex. Strumigenys semirex Bolton, 2000: 977 (w.) AUSTRALIA.

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



Holotype. TL 2.7, HL 0.75, HW 0.60, CI 80, ML 0.26, MI 35, SL 0.34, SI 57, PW 0.34, AL 0.77. Characters of emdeni-complex; closely related to emdeni and answering that description except for the following. Inner margin of mandible with a very slender cuticular crest; carina-like. Outer curvature of eyes just visible in full-face view, the upper scrobe margins straight rather than shallowly convex. Cephalic dorsum densely clothed with spoon-shaped to scale-like ground-pilosity but this pilosity not reproduced on promesonotal dorsum. Promesonotal ground-pilosity consists of scattered small spatulate hairs, the overall appearance of which is much less dense and much weaker than on the cephalic dorsum. Pronotal humeral hair absent; mesonotum with a single pair of short standing hairs. First gastral tergite with numerous erect stiff hairs that are slightly thickened or flattened apically, or weakly remiform. Dorsum of head and alitrunk reticulate-punctate but side of alitrunk with katepisternum, most of metapleuron and part of side of propodeum smooth. Disc of postpetiole smooth and shining.

Type Material

Holotype worker, Australia: North East Queensland, Bellenden-Ker, Centre Peak Summit, 23.x.1980, QM Berlesate No. 266, 17.16S, 145.52E, 1560 m, rainforest, sieved litter (G. B. Monteith) (Australian National Insect Collection).


  • Bolton, B. 2000. The ant tribe Dacetini. Memoirs of the American Entomological Institute. 65:1-1028. (page 977, worker described)]