Strumigenys ultromalyx

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

Strumigenys ultromalyx casent0005657 profile 1.jpg

Strumigenys ultromalyx casent0005657 dorsal 1.jpg

Specimen labels

Known from litter-samples from wet forest habitats.


A member of the arnoldi complex in the Strumigenys arnoldi-group.

Keys including this Species


Distribution based on Regional Taxon Lists

Afrotropical Region: Cameroun, Gabon (type locality), Uganda.

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 Online Catalogue of the Ants of the World.

  • ultromalyx. Strumigenys ultromalyx Bolton, 2000: 598 (w.) GABON.

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



Holotype. TL 2.4, HL 0.69, HW 0.60, CI 87, ML 0.26, MI 38, SL 0.34, SI 57, PW 0.32, AL 0.64. Characters of arnoldi-complex. Mandible short and stout, of approximately constant width from base to distal preapical tooth and through this length the outer margin about straight. In full-face view the inner ventral margin of the mandible, in the distal half of the mandible length, plainly visible, distinctly projecting farther mesially than the inner dorsal margin and crossed by the proximal preapical tooth. Proximal preapical tooth located distal of the mandibular midlength, stoutly conical and slightly recurved, much longer and stouter than the distal preapical tooth. Scape conspicuously flattened and distinctly expanded, its leading edge markedly convex. Cephalic dorsum with a transverse row of 4 remiform hairs close to the occipital margin, these hairs only slightly larger and slightly more elevated than the broad ground-pilosity; without standing hairs anterior to this row. Pronotal humeral hair absent; side of pronotum unsculptured. Pronotal dorsum longitudinally rugulose. Disc of postpetiole apparently unsculptured (all specimens with dense waxy bloom on disc). Hairs on first gastral tergite coarse and very stoutly remiform, some appearing almost clavate in dorsal view.

Paratypes. TL 2.2-2.4, HL 0.62-0.69, HW 0.54-0.61, CI 85-90, ML 0.25-0.26, MI 37-40, SL 0.30-0.34, SI 54-59, PW 0.28-0.32, AL 0.58-0.64 (10 measured).

Type Material

Holotype worker, Gabon: Provo Woleu-Ntem, 31.3 km. 108° ESE Minvoul, 2°04.8'N, 12°24.4'E, 600 m., 11.ii.1998, #1648(8) (B. L. Fisher) (The Natural History Museum).

Paratypes. 23 workers with same data as holotype but samples #1648 (5, 10, 12, 13, 14, 29, 33, and 34) (BMNH, South African Museum, Museum of Comparative Zoology, Los Angeles County Museum of Natural History, coll. Fisher).


  • Bolton, B. 2000. The ant tribe Dacetini. Memoirs of the American Entomological Institute. 65:1-1028. (page 598, worker described)

References based on Global Ant Biodiversity Informatics

  • Bolton, B. 2000. The Ant Tribe Dacetini. Memoirs of the American Entomological Institute 65
  • Fisher B. L. 2004. Diversity patterns of ants (Hymenoptera: Formicidae) along an elevational gradient on Monts Doudou in southwestern Gabon. Memoirs of the California Academy of Sciences 28: 269-286.