Strumigenys nykara

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Strumigenys nykara
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Strumigenys
Species: S. nykara
Binomial name
Strumigenys nykara
(Bolton, 1983)

Pyramica nykara casent0102551 profile 1.jpg

Pyramica nykara casent0102551 dorsal 1.jpg

Specimen labels

One worker of this species was noted as being collected from leaf litter in a primary forest.

Identification

Bolton (2000) - A member of the Strumigenys weberi-group. Disc of postpetiole coarsely longitudinally costulate; head distinctly broader than Strumigenys minkara. Petiole node without a spongiform posterior collar. Disc of postpetiole swollen, in dorsal view not completely surrounded by spongiform tissue. Anterior collar of postpetiole very narrow and lamellate, not confluent with lateral spongiform lobe. Clypeus posteriorly with a transverse row of 4 almost vertical stout hairs; anterior to this the clypeal dorsum with shorter standing simple hairs.

Bolton (1983) - Related to Strumigenys enkara and Strumigenys minkara by its possession of a sculptured postpetiolar disc, nykara is separated from the latter by its shorter broader head, punctate pleurae and different cephalic pilosity. From the former nykara is differentiated by the characters given in the key and noted under enkara.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Afrotropical Region: United Republic of Tanzania, Zimbabwe (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.

  • nykara. Smithistruma nykara Bolton, 1983: 307 (w.) ZIMBABWE. Combination in Pyramica: Bolton, 1999: 1673; in Strumigenys: Baroni Urbani & De Andrade, 2007: 125. See also: Bolton, 2000: 339.

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 2.4, HL 0.66, HW 0.43, CI 65, ML 0.07, MI 12, SL 0.31, SI 72, PW 0.29, AL 0.63.

Basal lamella of mandible not visible, what can be seen of dentition as described for enkara. Anterior clypeal margin transverse, the lateral margins very shallowly convex and feebly convergent anteriorly. Clypeus laterally and dorsally with fine short simple ground-pilosity which is mostly anteriorly curved and quite closely applied to the surface, and also with conspicuous much longer simple stouter hairs which are blunt apically. In profile these long hairs arise almost vertically from the clypeal dorsum, are shorter anteriorly and longest posteriorly where they form a transverse row of 4. In full-face view the long hairs project laterally or anterolaterally from the margins and are upcurved in the apical half to one-third of their length. Sides of head with numerous projecting fine simple hairs which are feebly flagellate, arched or looped. Dorsum of head behind clypeus with short anteriorly curved ground-pilosity such as is seen on the clypeus but towards the vertex and from the vertex to the occipital margin with fine simple hairs which are short flagellate, arched or looped. Long stout hairs such as those described on the clypeus are absent from the cephalic dorsum proper. Dorsum of head reticulate-rugulose, the clypeus less regularly rugulose. Antennal scapes feebly bent at about the basal third, broadest just distal to this. Leading edge of scape with a series of simple long projecting curved hairs. Maximum diameter of eye 0.14 X HW. Pronotum not marginate laterally, without a median longitudinal ridge or carina dorsally. In profile the metanotal groove not impressed, the propodeal teeth broad basally but narrowly triangular at apex, and with a narrow but distinct infradental lamella. Dorsal surfaces of pronotum, mesonotum, petiole, postpetiole and gaster with numerous fine simple hairs which are mostly short flagellate but some of which are curved or looped apically. Dorsal (outer) surfaces of middle and hind tibiae with numerous simple projecting hairs, many of which are curved or subflagellate. Sides of pronotum reticulate-rugose, pleurae densely punctate. Dorsal alitrunk everywhere finely but strongly reticulate-rugose, the spaces between the rugae not punctate except posteriorly on the propodeum where they form the main sculpture between the bases of the teeth. Petiole dorsum reticulate-rugose and the anterior face with a narrow transverse crest; the disc of the postpetiole strongly longitudinally rugose. Basigastral costulae strongly developed, covering the basal third or slightly more of the tergite. With pedicel segments in profile the spongiform appendages strongly developed. In dorsal view the petiole node with a narrow posterior strip which is broadest posterolaterally and interrupted medially. Sides of postpetiole disc not bounded by spongiform tissue in dorsal view. Posterior margin of postpetiole with a spongiform strip which is broad posterolaterally but concave and much narrowed medially, and interrupted centrally. Base of first gastral tergite with a transverse strip which is mostly laminar and is traversed by the basal costulae. Colour medium brown.

Paratypes. TL 2.4-2.6, HL 0.65-0.70, HW 0.44-0.47, CI 66-68, ML 0.07, MI 10-12, SL 0.31-0.34, SI 71-73, PW 0.28-0.32, AL 0.62-0.70 (4 measured).

As holotype, the maximum diameter of the eye 0.14-0.16 X HW.

Type Material

Holotype worker, Zimbabwe: Umtali, Melsetter, 1700 m, ii.1969 (R. Mussard) (Musee d'Histoire Naturelle Genève).

Paratypes. 4 workers with same data as holotype (MHNG; The Natural History Museum; Museum of Comparative Zoology).

References