Strumigenys malaplax

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

Strumigenys malaplax casent0900092 p 1 high.jpg

Strumigenys malaplax casent0900092 d 1 high.jpg

Specimen Labels

Known from two litter samples, one from a mature wet forest and the other from cocoa.

Identification

Bolton (1983) - A member of the Strumigenys weberi-group. Three non-paratypic specimens, each from a different locality, resemble the holotype in all main characters but show some sculptural variation. The species is characterised and separated from other members of the group by having a smooth postpetiolar disc, no metanotal groove, and by having specialized long stout clypeal hairs which are absent from the dorsum of the head behind the clypeus where only fine simple hairs are present. Other members of the group having a smooth postpetiole and lacking a metanotal groove (Strumigenys arahana, Strumigenys fenkara, Strumigenys placora, Strumigenys synkara, Strumigenys tolomyla) all have very obvious specialized hairs on the cephalic dorsum which are similar to or even longer than those on the clypeus.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Afrotropical Region: Angola (type locality), Cameroun, Democratic Republic of Congo, Ghana, Nigeria, Uganda.


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.

  • malaplax. Smithistruma malaplax Bolton, 1983: 304 (w.) ANGOLA. Combination in Pyramica: Bolton, 1999: 1673; in Strumigenys: Baroni Urbani & De Andrade, 2007: 123. See also: Bolton, 2000: 338.

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 2.1, HL 0.64, HW 0.40, CI 63, ML 0.07, MI 11, SL 0.28, S1 70, PW 0.28, AL 0.62.

Basal lamella of mandible a high truncated rectangle with concave sides, separated from the principal tooth row by a small diastema. Of the 5 teeth following the diastema the first is the shortest and the second is the longest. The principal row of 5 teeth is followed by two slightly smaller teeth, 4 minute denticles and a small apical tooth. Anterior clypeal margin transverse, the sides feebly convergent. In full-face view the lateral clypeal margins with a more ventrally situated series of projecting fine simple hairs which are curved anteriorly, often sharply so. Situated above this row on the sides of the clypeus are numerous longer stouter weakly clavate hairs which project laterally or anterolaterally and are upcurved or backcurved in the distal third to half of their length. Clypeal dorsum with very sparse short anteriorly curved simple ground-pilosity and with numerous erect to suberect long stout weakly clavate hairs. Anteriorly on the clypeus the stout hairs curve forward from their bases then upwards and usually slightly backwards. P9steriorly on the clypeus is a single transverse row of stout clavate hairs which are much longer than those situated anteriorly and which are vertical, weakly sinuate throughout their length and weakly directed anteriorly at their apices (from the non-paratypic material as the posterior row of clavate hairs is crushed down in the holotype). Dorsum of head behind clypeus only with simple fine pilosity, without the long weakly clavate hairs which are so obvious on the clypeus; the fine hairs simply anteriorly curved and closely applied to the surface in the area behind the clypeus but posterior to that, approaching the vertex and beyond, the hairs are arched, looped or weakly flagellate. With the head in full-face view the sides with projecting simple hairs similar to those on the dorsum, weakly flagellate, arched or looped. Scape feebly bent at its basal third, broadest at about the midlength and the leading edge with a row of projecting simple curved hairs. Maximum diameter of eye 0.16 X HW. Pronotum not marginate laterally, without a median dorsal ridge or carina. With alitrunk in profile the metanotal groove absent, not impressed. Propodeal teeth triangular and acute, subtended by a narrow evenly concave infradental lamella. Dorsal surfaces of pronotum, mesonotum, petiole, postpetiole and gaster with numerous fine simple hairs which are arched, looped or weakly flagellate. Sides of pronotum and propodeum reticulate-rugulose, the pleurae punctate. Promesonotal dorsum densely and strongly rugulose. Propodeal dorsum rugulose and with vestigial punctures. Dorsum of petiole node rugulose, the postpetiole smooth and shining. First gastral tergite unsculptured except for the strong basigastral costulae. Spongiform appendages of pedicel segments strongly developed in profile. In dorsal view the broad posterior strip of the petiole node concave medially. Postpetio!e surrounded by spongiform material in dorsal view, the broad posterior strip indented medially. Spongiform material at base of first gastral tergite forming a narrow band which is mostly overlapped by the posterior postpetiolar spongiform tissue, the area of the first tergite immediately behind the spongiform material lamellar and traversed by the basigastral costulae. Colour orange-brown, the gaster blackish brown.

Bolton (2000) - TL 2.0-2.1, HL 0.58-0.64, HW 0.37-0.40, CI 62-67, ML 0.06-0.07, MI 10-12, SL 0.26-0.30, SI 70-76, PW 0.25-0.28, AL 0.58-0.62 (7 measured).

Type Material

Holotype worker, Angola: nr Gubela, 17 .iii. 1972, forest litter (P. Hammond) (The Natural History Museum).

References