Strumigenys deverra

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

Strumigenys deverra casent0005513 profile 1.jpg

Strumigenys deverra casent0005513 dorsal 1.jpg

Specimen labels

Known from a range of forest habitats. Collections have been made from rotten logs and litter samples.

Identification

Bolton (2000) - A member of the chroa complex in the Strumigenys scotti-group. S. deverra is distinguished from other species in the chroa-complex by having a lamellate upper scrobe margin, pronotal humerus with a flagellate hair, and remiform to broadly clavate hairs on petiole, postpetiole and first gastral tergite.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Malagasy Region: Madagascar (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

Worker

Nomenclature

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

  • deverra. Strumigenys deverra Fisher, in Bolton, 2000: 675 (w.) MADAGASCAR.

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 3.1, HL 0.74, HW 0.56, CI 76, ML 0.30, MI 41, SL 0.44, SI 78, PW 0.35, AL 0.80. Characters of chroa-complex. Mandibles almost straight and at full closure parallel except at base. Basal half of proximal preapical mandibular tooth confluent with lamella on inner margin which extends to base of mandible; in full-face view inner margin of lamella more or less straight. Upper scrobe margin a narrow lamella, about half as wide as scape. Maximum diameter of eye about equal to or slightly smaller than maximum width of scape. Hairs on leading edge of scape spatulate. Cephalic dorsum with rows of curved narrow spatulate to spoon-shaped ground-pilosity, the upper scrobe margins fringed with a dense row of hairs which are the same shape and size as those on the dorsum. Cephalic dorsum with 6 standing remiform to clavate hairs arranged in a transverse row of 4 close to the occipital margin and a more anteriorly situated pair. Pronotal humeral hair flagellate. Anterior margin of mesonotum with a pair of stout remiform hairs; posterior mesonotum with 2 additional pairs which are similar in shape but shorter. Propodeum with a pair of narrow remiform hairs immediately anterior of propodeal spines. Ground-pilosity on alitrunk sparse and similar in size and shape as on head. Dorsum of alitrunk in outline convex anteriorly and more or less flat posteriorly; posterior portion of mesonotum slightly depressed below the anterior margin of propodeum. Humeral angle centrally marginate. Anterior mesonotum with a lamellate extension above a deeply impressed mesothoracic spiracle. Propodeal tooth broadly triangular, lamellate, pointed apically; subtended by a greatly expanded lamella. Alitrunk dorsum densely reticulate-punctate; pleurae mostly smooth and shiny, peripherally reticulate-punctate. Disc of postpetiole conspicuously broader than long, smooth and shiny with superficial longitudinal carinulate sculpture laterally. Ventral and lateral spongiform tissue of petiole and postpetiole moderately developed. Base of first gastral tergite with short costulae radiating on each side of a narrow central clear area. Dorsal surfaces of petiole, postpetiole and gaster with standing remiform to broadly clavate hairs. Colour dull yellowish brown.

Paratypes. TL 2.9-3.2, HL 0.71-0.79, HW 0.53-0.60, CI 74-77, ML 0.29-0.31, MI 39-43, SL 0.42-0.46, SI 77-81, PW 0.32-0.37, AL 0.75-0.83 (5 measured). As holotype except that they showed variation in the strength of the development of the lamella on the propodeal declivity.

Members of these series slightly extend the range shown by the type-series: HL 0.70-0.76, HW 0.52- 0.57, CI 74-77, ML 0.29-0.31, MI 41-42, SL 0.40-0.44, SI 76-79 (3 measured).

Type Material

Holotype worker, Madagascar: 45 km. S Ambalavao, 22°13'S, 47°01'E, 785 m., 25.ix.1993, sifted litter (leaf mold rotten wood), rainforest #696 (35)-12 (B. L. Fisher) (Museum of Comparative Zoology).

Paratypes. 1 worker with same data as holotype; 4 workers with same data but coded (18)-13, (11)-15 (The Natural History Museum, South African Museum).

References

  • Fisher, B.L. 2000. The Malagasy fauna of Strumigenys. Pp. 612-696 in: Bolton, B. 2000. The ant tribe Dacetini. Memoirs of the American Entomological Institute. 65:1-1028. (page 675, worker described)