Strumigenys edaragona

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

Known from various kinds of wet-forest habitats with specimens obtained from litter-sample collections. Heterick & Kitching (2022) collected this species in a pitfall trap within a lowland dipterocarp forest in Brunei.

Identification

Bolton (2000) - A member of the rofocala complex in the Strumigenys godeffroyi-group. The strongly constricted base to the apical antennal segment, coupled with the smooth pleurae and side of propodeum, separate this species from Strumigenys baal. Both these characters are shared with Strumigenys rofocala which is, however, a smaller species (compare measurements) in which the apicoscrobal hair is not strongly differentiated from those that follow it on the dorsolateral margin of the occipital lobe.

Keys including this Species

Key to Strumigenys of East Asia

Distribution

Distribution based on Regional Taxon Lists

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

edaragona. Strumigenys edaragona Bolton, 2000: 816 (w.) INDONESIA (Sumatra).

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 2.2, HL 0.59, HW 0.41, CI 69, ML 0.26, MI 44, SL 0.34, SI 83, PW 0.26, AL 0.59. Characters of rojocala -complex. Base of sixth antennomere very narrow, strongly constricted to its articulation with the preapical segment. Apicoscrobal hair long and simple; 2-3 similar but much shorter hairs project from margin posterior to this. Cephalic dorsum with a transverse row of 4-6 stiffly erect simple hairs at the occipital margin; anterior to this the head with short ground-pilosity that is straight, elevated and inclined anteriorly, but without erect hairs similar to those at the occipital margin. Pronotal humeral hair long flagellate. Dorsum of pronotum and mesonotum each with a single pair of erect hairs. Dorsum of alitrunk densely reticulate-punctate except for pronotal dorsum where a few weak longitudinal rugulae are present and the reticulate-punctate component is somewhat effaced. Pleurae and side of propodeum smooth. Dorsum of petiole node reticulate-punctate; disc of postpetiole smooth. Lateral spongiform lobe of petiole moderately large, in profile the lobe extends forward to just beyond midlength of node but does not attain the anterior face of the node; in same view height of anterior face of node less than length of dorsum. Basigastral costulae strongly developed, about equal in length to disc of postpetiole. First gastral tergite with simple or flagellate standing hairs.

Paratype. TL 2.2, HL 0.60, HW 0.41, CI 68, ML 0.27, MI 45, SL 0.36, SI 88, PW 0.25, AL 0.59.

Type Material

Holotype worker, Malaysia: Sabah, Crocker Ra., 19.v.1987, 1200 m., no. 31a (Burckhardt & Lobl) (Musee d'Histoire Naturelle Genève).

Paratypes. 1 worker, Malaysia: Sabah, G. Silam, 1981 (R. Leakey); 2 workers, Sabah, Poring Hot Springs, 9.v.1987, 600 m., no. 18 (Burckhardt & Lobl) (The Natural History Museum, MHNG).

References

Bolton, B. 2000. The ant tribe Dacetini. Memoirs of the American Entomological Institute. 65:1-1028. (page 816, worker described)
Heterick, B.E., Kitching, R.L. 2022. The ants (Hymenoptera: Formicidae) of a one-hectare plot of lowland dipterocarp forest. Entomologist’s Monthly Magazine 158(4), 261–272 (doi:10.31184/m00138908.1584.4153).
Musfira, S.H., Rafi, M., Gusti, M., Putri, D.H., Satria, R. 2022. New data on the genus Strumigenys (Hymenoptera: Formicidae) from Sumatra. Zoosystematica Rossica 31(1): 74–86 (doi:10.31610/zsr/2022.31.1.74).
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

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