Strumigenys rhadina

Every Ant Tells a Story - And Scientists Explain Their Stories Here
Jump to navigation Jump to search
Strumigenys rhadina
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Strumigenys
Species: S. rhadina
Binomial name
Strumigenys rhadina
Bolton, 2000

Strumigenys rhadina casent0102582 profile 1.jpg

Strumigenys rhadina casent0102582 dorsal 1.jpg

Specimen labels

Known from a small number of collections, the meager data available (mesic forest habitat litter-samples) suggests this is a ground/litter dwelling species that lives in wet forests.

Identification

Bolton (2000) - A member of the rhadina complex in the Strumigenys caniophanes-group. Only two species in the group have a lamella on the inner margin of the mandible, rhadina and Strumigenys sardella. The latter has standard indices in the same range as the former but is larger and has differently arranged pilosity. S. sardella lacks projecting hairs on the tibiae and basitarsi; it has only 2 freely laterally projecting hairs on the dorsolateral margin of the head, these are short (less than 0.20 X SL) and do not arise from tubercles. Apart from the hairs at the occipital margin the cephalic dorsum of sardella has only a single other pair of standing hairs, near the highest point of the vertex.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Indo-Australian Region: Borneo (type locality), Indonesia, Malaysia.


Distribution based on AntMaps

AntMapLegend.png

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.

  • rhadina. Strumigenys rhadina Bolton, 2000: 764 (w.) BORNEO.

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, HL 0.63, HW 0.51, CI 81, ML 0.25, MI 40, SL 0.30, SI 59, PW 0.30, AL 0.66. Mandible with a stout preapical tooth, the inner margin proximal of the tooth with a prominent cuticular lamella that is broadest near the tooth and tapers basally; maximum width of lamella less than half length of preapical tooth. With head in full-face view the dorsolateral margin with numerous hairs that freely project laterally; 5-7 of these are relatively long (0.35-0.50 X SL) and arise from small but distinct tubercles, the remainder are shorter. Cephalic dorsum with erect hairs present from posterior margin of clypeus to occipital margin. Pronotal humeral hair long, weakly flagellate. Promesonotal dorsum with numerous erect hairs, those lining the dorsolateral margin arising from distinct tubercles. Waist segments and first gastral tergite with numerous standing hairs that are similar to those on the promesonotum. All standing hairs are stiffly filiform and simple, mostly acute apically. Middle and hind tibiae and basitarsi with projecting long hairs present. Dorsal surfaces of femora without erect hairs. Pleurae and side of propodeum unsculptured and smooth except for extreme periphery. Petiole node in dorsal view slightly broader than long. In profile the node with a steep anterior face that is longer than the dorsum, the latter short and rounding evenly into a shallowly sloping longer posterior surface.

Paratype. TL 2.3, HL 0.65, HW 0.51, CI 78, ML 0.25, MI 38, SL 0.30, SI 59, PW 0.30, AL 0.66.

Type Material

Holotype worker, Malaysia: Sarawak, Santubong, Kuching, v. 1994 (Lobl & Burckhardt) (Musee d'Histoire Naturelle Genève).

Paratype. 1 worker with same data as holotype (The Natural History Museum).

References

  • Bolton, B. 2000. The ant tribe Dacetini. Memoirs of the American Entomological Institute. 65:1-1028. (page 764, worker described)