Strumigenys amasara

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

Specimens were collected from a litter sample in secondary wet forest.

Identification

Bolton (2000) - A member of the koningsbergeri complex in the Strumigenys koningsbergeri-group. Like Strumigenys seynoka this species has hypertrophied femoral gland bullae but they are smaller here than in seynoka and strangely are absent from the forelegs; see notes under Strumigenys koningsbergeri.

Keys including this Species

Key to Strumigenys of East Asia

Distribution

Latitudinal Distribution Pattern

Latitudinal Range: 4.966666667° to 4.95°.


North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

Source: AntMaps

Distribution based on Regional Taxon Lists

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

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.

amasara. Strumigenys amasara Bolton, 2000: 837 (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 2.9, HL 0.86, HW 0.74, CI 86, ML 0.36, MI 42, SL 0.44, SI 59, PW 0.37, AL 0.81. With characters of koningsbergeri-complex. Preocular concavity extends onto ventral surface of head as a short but broad impression. Upper scrobe margins shallowly convex and evenly divergent, not flared outward at nearly a right-angle at level of eye; only extreme outer arc of eye is visible in full-face view. Upper scrobe margin with a weakly jagged appearance as the small curved hairs that fringe the margin each arises from a small tubercle. Depression across posterior vertex of head broad but very shallow. Pronotum without a pair of short standing hairs close to anterodorsal margin. Mesonotum with a single pair of short erect hairs. Katepisternum mostly smooth, metapleuron finely reticulate-punctate or with a smooth patch. Bullae of femoral glands large and conspicuous on middle and hind legs, absent from forelegs. With hind leg in dorsal view maximum length of bulla about 0.33 X length of femur and its width about 0.50 X maximum width of femur. Bullae of glands present on all tibiae, large and very conspicuous on middle and hindlegs. Lamella on propodeal declivity broad, its posterior (free) margin shallowly convex. Standing hairs on first gastral tergite stout, simple or weakly expanded toward the apex.

Paratypes. TL 2.8-2.9, HL 0.83-0.86, HW 0.70-0.74, CI 83-87, ML 0.35-0.37, MI 40-43, SL 0.42-0.46, SI 58-63, PW 0.35-0.37, AL 0.75-0.81 (9 measured).

Type Material

Holotype worker, Malaysia: Sarawak, 4th Division, Gn. Mulu N. P., v-viii.1978, B. M. 1978-49 (P. M. Hammond & J. E. Marshall) (The Natural History Museum). Paratypes. 12 workers with same data as holotype (BMNH, Museum of Comparative Zoology, Musee d'Histoire Naturelle Genève).

References

Bolton, B. 2000. The ant tribe Dacetini. Memoirs of the American Entomological Institute. 65:1-1028. (page 837, worker described)
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
Pfeiffer M., and D. Mezger. 2012. Biodiversity Assessment in Incomplete Inventories: Leaf Litter Ant Communities in Several Types of Bornean Rain Forest. PLoS ONE 7(7): e40729. doi:10.1371/journal.pone.0040917
Pfeiffer M., and D. Mezger. 2012. Biodiversity Assessment in Incomplete Inventories: Leaf Litter Ant Communities in Several Types of Bornean Rain Forest. PLoS ONE 7(7): e40729. doi:10.1371/journal.pone.0040980
Pfeiffer M.; Mezger, D.; Hosoishi, S.; Bakhtiar, E. Y.; Kohout, R. J. 2011. The Formicidae of Borneo (Insecta: Hymenoptera): a preliminary species list. Asian Myrmecology 4:9-58
Woodcock P., D. P. Edwards, R. J. Newton, C. Vun Khen, S. H. Bottrell, and K. C. Hamer. 2013. Impacts of Intensive Logging on the Trophic Organisation of Ant Communities in a Biodiversity Hotspot. PLoS ONE 8(4): e60756. doi:10.1371/journal.pone.0060756
Woodcock P., D. P. Edwards, T. M. Fayle, R. J. Newton, C. Vun Khen, S. H. Bottrell, and K. C. Hamer. 2011. The conservation value of South East Asia's highly degraded forests: evidence from leaf-litter ants. Phil. Trans. R. Soc. B. 366: 3256-3264.
Woodcock P., D.P. Edwards, T.M. Fayle, R.J. Newton, C. Vun Khen, S.H. Bottrell, and K.C. Hamer. 2011. The conservation value of South East Asia's highly degraded forests: evidence from leaf-litter ants. Phil. Trans. R. Soc. B 366: 3256-3264.