Strumigenys nannosobek

Strumigenys nannosobek
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Myrmicinae
Tribe:	Attini
Genus:	Strumigenys
Species:	S. nannosobek
Binomial name
	Strumigenys nannosobek; (Bolton, 2000) Specimen Labels

Nothing is known about the biology of Strumigenys nannosobek.

Identification

Bharti & Akbar (2013) - A member of the Strumigenys murphyi-group. This is the only species of the group (murphyi group) to have long erect hairs on the middle and hind tibiae and basitarsi, and is the only species to have hairs on the leading edge of the scape that are universally curved toward the apex of the scape. It also has the longest mandibles yet recorded in the group (Bolton, 2000).

Bolton (2000) - This is the only species of the group to have long erect hairs on the middle and hind tibiae and basitarsi, and is the only species to have hairs on the leading edge of the scape that are universally curved toward the apex of the scape. It also has the longest mandibles yet recorded in the group.

Keys including this Species

Distribution

Latitudinal Distribution Pattern

Latitudinal Range: 9.5° to 9.5°.


North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

Source: AntMaps

Distribution based on Regional Taxon Lists

Oriental Region: Bhutan (type locality), India.

Distribution based on AntMaps

Distribution based on AntWeb specimens

Check data from AntWeb

Countries Occupied

Number of countries occupied by this species based on AntWiki Regional Taxon Lists. In general, fewer countries occupied indicates a narrower range, while more countries indicates a more widespread species.

Estimated Abundance

Relative abundance based on number of AntMaps records per species (this species within the purple bar). Fewer records (to the left) indicates a less abundant/encountered species while more records (to the right) indicates more abundant/encountered species.

Biology

Explore Overview of Strumigenys 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.

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Castes

Nomenclature

The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

nannosobek. Pyramica nannosobek Bolton, 2000: 453 (w.) BHUTAN. Combination in Strumigenys: Baroni Urbani & De Andrade, 2007: 124

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 1.5, HL 0.35, HW 0.42, CI 120, ML 0.18, MI 51, SL 0.20, SI 48, PW 0.25, AL 0.42. Inner margin of mandible with a series of medially directed small hairs and with 6-7 small preapical teeth, the third from the base is the largest, narrowly triangular and located at about the midlength of the mandible (this tooth is doubled in one of the paratypes). Apicodorsal tooth the longest and overlaps its counterpart from the opposing mandible, spiniform but not extending beyond the outer margin of the opposing mandible at full closure. Anterior clypeal margin with a few short, flattened projecting hairs; clypeal dorsum only with small orbicular hairs. Dorsum of head posterior to clypeus without orbicular hairs. Transverse crest of vertex conspicuous, approximately straight across most of vertex but on each side curved forward toward the anterolateral angle of the occipital lobe. Sides of occipital lobes in full-face view more or less straight, weakly convergent posteriorly. Leading edge of scape with a row of narrowly spatulate hairs that are curved toward the apex of the scape. Apex of subbasal lobe of scape with an elongate spatulate hair that is directed anteriorly; inner margin of subbasal lobe with 2-3 narrowly spoon-shaped hairs that curve toward the apex of the lobe. Head and alitrunk otherwise with minute inconspicuous ground-pilosity but without standing hairs of any form. Eye minute, of 2-3 very small ommatidia. Head finely and densely reticulate-punctate. Pronotal dorsum with a few feeble, posteriorly divergent fine longitudinal costulae; dorsum depressed along line of promesonotal junction. Mesonotum in profile very shallowly convex, highest posteriorly. Pleurae smooth. Dorsal (outer) surfaces of middle and hind tibiae, and middle and hind basitarsi, each with 1-2 long erect freely projecting hairs (obscured by glue in holotype, visible in paratypes). Petiole and postpetiole without standing hairs but first gastral tergite with short erect simple pilosity. Petiole node broader than long in dorsal view, finely shagreenate and dull. Disc of postpetiole finely shagreenate to smooth, much less strongly sculptured than petiole node. Basigastral costulae strongly developed, longer than disc of postpetiole.

Paratypes. TL 1.4-1.5, HL 0.33-0.35, HW 0.39-0.42, CI 118-120, ML 0.18-0.19, MI 51-55, SL 0.19-0.20, PW 0.23-0.25, AL 0.40-0.43 (4 measured).

Type Material

Holotype worker, Bhutan: Kamjee, 24.4., Nat.-Hist. Museum Basel - Bhutan Expedition 1972 (no collector's name) (Naturhistorisches Museum, Basel).

Paratypes. 1 worker with same data as holotype; 3 workers, Bhutan: Phuntsholing, 2/400 m., 15.4., Nat.-Hist. Museum Basel - Bhutan Expedition 1972 (no collector' s name) (NHMB, The Natural History Museum).

References

Baroni Urbani, C. and de Andrade, M.L. 2007. The ant tribe Dacetini: limits and constituent genera, with descriptions of new species. Annali del Museo Civico di Storia Naturale “G. Doria”. 99:1-191.
Bharti, H. & Akbar, S.A. 2013. Taxonomic studies on the ant genus Strumigenys Smith, 1860 (Hymenoptera, Formicidae) with report of two new species and five new records including a tramp species from India. Sociobiology 60, 387-396 (doi:10.13102/sociobiology.v60i4.387-396).
Bolton, B. 2000. The ant tribe Dacetini. Memoirs of the American Entomological Institute. 65:1-1028. (page 453, worker described)
Dendup, K.C., Dorji, C., Dhadwal, T., Bharti, H., Pfeiffer, M. 2021. A preliminary checklist of ants from Bhutan. Asian Myrmecology 14, e014005 (doi:10.20362/am.014005).
Tang, K. L., Guénard, B. 2023. Further additions to the knowledge of Strumigenys (Formicidae: Myrmicinae) within South East Asia, with the descriptions of 20 new species. European Journal of Taxonomy 907, 1–144 (doi:10.5852/ejt.2023.907.2327).

References based on Global Ant Biodiversity Informatics

Bolton, B. 2000. The Ant Tribe Dacetini. Memoirs of the American Entomological Institute 65
Dad J. M., S. A. Akbar, H. Bharti, and A. A. Wachkoo. 2019. Community structure and ant species diversity across select sites ofWestern Ghats, India. Acta Ecologica Sinica 39: 219–228.