Aenictus latifemoratus

Aenictus latifemoratus
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Dorylinae
Genus:	Aenictus
Species:	A. latifemoratus
Binomial name
	Aenictus latifemoratus; Terayama & Yamane, 1989 Specimen Labels

Specimens from West Sumatra and Sarawak were collected in relatively good rainforests from columns on the forest floor.

Identification

A member of the silvestrii species group. Aenictus jarujini is very similar and closely related to A. latifemoratus but the two are easily separated by the following characters: number of antennal segments (9 in A. jarujini; 8 in A. latifemoratus); shape of petiolar node (node subrectangular and relatively low, posteriorly margined with a rim in A. jarujini; node without a distinct rim in A. latifemoratus), condition of subpetiolar process (very low in A. jarujini; well developed and subtriangular in A. latifemoratus); sculpturing on head (strongly macropunctate in posterior dorsal half of head, other regions only weakly macropunctate in A. jarujini; strongly macropunctate or recticulate extensively on dorsum and sides of head in A. latifemoratus).

Keys including this Species

Key to Aenictus silvestrii group species

Distribution

Borneo (Sarawak), West Sumatra, and West Java

Distribution based on Regional Taxon Lists

Indo-Australian Region: Borneo, 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 Aenictus biology

Little is known about the biology of Aenictus latifemoratus. The genus is comprised of species that live an army ant lifestyle. Aenictus typically prey on other ants, from other genera, or other insects such as wasps or termites. There are reports of Aenictus preying on other insects as well and even have been observed collecting honeydew from homopterans (Santschi, 1933; Gotwald, 1995) but this appears, at least from available evidence, to be uncommon. Foraging raids can occur day or night across the ground surface. Occasionally raids are arboreal. During a raid numerous workers attack a single nest or small area, with several workers coordinating their efforts to carry large prey items back to the nest or bivouac. Aenictus have a nomadic life style, alternating between a migratory phase in which nests are temporary bivouacs in sheltered places above the ground and a stationary phase where semi-permanent underground nests are formed. During the nomadic phase bivouacs move regularly, sometimes more than once a day when larvae require large amounts of food. Individual nests usually contain up to several thousand workers, although nest fragments containing only a few hundred workers are often encountered. Queens are highly specialised and look less like workers than in most ant species. They have greatly enlarged gasters (dichthadiform) and remain flightless throughout their life. New colonies are formed by the division of existing colonies (fission) rather than by individual queens starting colonies on their own.

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Castes

Known only from the worker caste.

Nomenclature

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

latifemoratus. Aenictus latifemoratus Terayama & Yamane, 1989: 600, figs. 3-6 (w.) INDONESIA (Sumatra).
- Type-material: holotype worker, 3 paratype workers.
- Type-locality: holotype Indonesia: Sumatra, Maninjau, 8.viii.1985 (Sk. & S. Yamane); paratypes with same data.
- Type-depositories: BZBC (holotype); BZBC, KUIC (paratypes).
- Status as species: Bolton, 1995b: 60; Jaitrong & Yamane, 2010: 331 (redescription); Pfeiffer, et al. 2011: 32.
- Distribution: Indonesia (Java, Sumatra), Malaysia (Sarawak).

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

Description

Worker

Jaitrong and Yamane (2010) - One paratype: TL 3.9 mm; HL 0.93 mm; HW 0.85 mm; SL 0.60 mm; ML 1.33 mm; MTL 0.63 mm; PL 0.28 mm; CI 92; SI 71. Nontype material (n = 5): TL 3.8–4.0 mm; HL 0.92–0.97 mm; HW 0.85–0.85 mm; SL 0.60–0.63 mm; ML 1.25–1.35 mm; MTL 0.63–0.65 mm; PL 0.27–0.33 mm; CI 90–95; SI 69–71.

Head slightly longer than broad, with weakly convex sides; seen in full-face view its posterior margin weakly convex; occiput with a well-demarcated collar bearing many carinae. Antenna 8-segmented; scape extending slightly beyond the midlength of head in full-face view; antennal segments II-III slightly broader than long or as broad as long; IV-VIII distinctly longer than broad, each bing broadened apically; VIII c. 2.0¥ as long as broad. Frontal carinae narrow and extending half length of head, sharply elevated and darkened in anterior half, and low and vestigial in posterior half. Clypeus short and roundly produced anteriorly, lacking anterior teeth. Mandible with apical tooth large and curved, followed by a series of 7–9 denticles; basal margin of mandible lacking denticles. Promesonotum in profile distinctly convex dorsally; propodeum lower than promesonotum, and its dorsal outline straight; propodeal junction acutely angulate; declivity of propodeum shallowly concave, encircled with a rim. Seen from side, petiole subrectangular, anteriorly weakly convex; its anterior face encircled with a sharp rim; subpetiolar process well developed and sub-triangular; postpetiole as long as petiole, seen from above distinctly broadened posteriorly, in profile roundly convex above, anteroventrally produced as a blunt angle directed downward and forward. Gaster elongate-elliptical, narrowed anteriorly and posteriorly.

Head almost wholly with macropunctures (somewhat reticulate) except for areas along frontal carinae; inter-spaces and bottoms with dense small punctures; macropunctues on sides of head sparser than in other regions. Mandible with very dense micropunctures, but smooth apically and along masticatory margin. Upper face of antennal scape basally with dense micropunctures and apically much smoother. Dorsum of mesosoma sculptured as in dorsum of head, but with sparser macro-punctures. Petiole with a weak reticulum superimposed with very dense small punctures (a condition similar to that of propodeal dorsum); postpetiole with dense small punctures. Gaster smooth and shining except for extreme base. Femora and tibiae smooth and shining.

Body with relatively sparse standing hairs mixed with sparse short hairs over the surface; length of the longest pronotal hair approximately 0.23 mm. Head, mesosoma and waist reddish brown to dark brown; gaster and legs yellow; mandibles blackish brown.

Type Material

Jaitrong and Yamane (2010) - Holotype worker and a paratype worker from Maninjau, W. Sumatra, Indonesia deposited in MZB, and a paratype deposited in SKYC (examined).

References

Jaitrong, W. and Yamane, S. 2010. The army ant Aenictus silvestrii and its related species in Southeast Asia, with a description of a new species (Hymenoptera: Formicidae: Aenictinae). Entomological Science. 13:328-333.
Borowiec, M.L. 2019. Convergent evolution of the army ant syndrome and congruence in big-data phylogenetics. Systematic Biology 68, 642–656 (doi:10.1093/sysbio/syy088).
Terayama, M.; Yamane, S. 1989. The army ant genus Aenictus (Hymenoptera, Formicidae) from Sumatra, with descriptions of three new species. Jpn. J. Entomol. 57: 597-603 (page 600, figs. 3-6 worker described)
Yamane, S., Tanaka, H.O., Hasimoto, Y., Ohashi, M., Meleng, P., Itioka, T. 2021. A list of ants from Lambir Hills National Park and its vicinity, with their biological information: Part II. Subfamilies Leptanillinae, Proceratiinae, Amblyoponinae, Ponerinae, Dorylinae, Dolichoderinae, Ectatomminae and Formicinae. Contributions from the Biological Laboratory, Kyoto University 31, 87–157.

References based on Global Ant Biodiversity Informatics

Borowiec M. L. 2016. Generic revision of the ant subfamily Dorylinae (Hymenoptera, Formicidae). ZooKeys 608: 1–280.
Jaitrong, W.; Yamane, S. 2010. The army ant Aenictus silvestrii and its related species in Southeast Asia, with a description of a new species (Hymenoptera: Formicidae: Aenictinae). Entomological Science 13:328-333.
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
Terayama M.; Yamane, S. 1989. The army ant genus Aenictus (Hymenoptera, Formicidae) from Sumatra, with descriptions of three new species. Japanese Journal of Entomology 57:597-603.