Aenictus sundalandensis

Aenictus sundalandensis
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Dorylinae
Genus:	Aenictus
Species:	A. sundalandensis
Binomial name
Aenictus sundalandensis Jaitrong & Yamane, 2013

The type series of this species was collected from the highland (ca. 1300 m alt., W. Java) in the night in an open site at a forest edge. The non-type colonies from Sumatra and Borneo were collected in both primary and disturbed forests.

Identification

A member of the ceylonicus group. Jaitrong and Yamane (2013) – Aenictus sundalandensis is similar to Aenictus fuchuanensis, Aenictus pinkaewi, and Aenictus maneerati in having the long cylindrical petiole and short head (CI 100-112). However, it is easily separated from the latter three by the central area of pronotum being superficially shagreened or reticulate, rather shiny, and the lateral face being reticulate with smooth and shiny bottoms.

Keys including this Species

• Key to southeastern Asian Aenictus ceylonicus group species

Distribution

Sumatra, Borneo (Sabah and E. Kalimantan), and Java

Distribution based on Regional Taxon Lists

Indo-Australian Region: 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 sundalandensis. 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. ‎

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.

• sundalandensis. Aenictus sundalandensis Jaitrong & Yamane, 2013: 209, fig. 22A-C (w.) INDONESIA (Java, Sumatra: Riau Is), BORNEO (East Malaysia: Sabah; Indonesia: Kalimantan).
  • Type-material: holotype worker, 26 paratype workers.
  • Type-locality: holotype Indonesia: Java, Cibodas Botanical Garden, 28.xi.2009, WJT09-ID01 (W. Jaitrong); paratypes with same data.
  • Type-depositories: MZBJ (holotype); BMNH, MCZC, MZBJ, SKYC, TNHM (paratypes).
  • Distribution: Indonesia (Java, Kalimantan, Sumatra), Malaysia (Sabah).

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

Description

Worker

(Holotype and paratype workers, n = 10). TL 3.00–3.30 mm; HL 0.61–0.68 mm; HW 0.65–0.73 mm; SL 0.54–0.56 mm; ML 1.03–1.13 mm; PL 0.25–0.29 mm; CI 106–108; SI 78–83.

Head in full-face view round, slightly broader than long, sides convex, posterior margin almost straight or feebly convex. Antennal scape relatively long, slightly extending beyond 2/3 of head length. Frontal carina relatively long, slightly extending beyond the level of posterior margin of torulus. Parafrontal ridge feeble and incomplete. Anterior clypeal margin concave, concealed by curved anterior extension of frontal carina. Masticatory margin of mandible with 4 teeth including a large apical tooth; basal margin almost straight or feebly concave. Maximum width of gap between anterior clypeal margin and mandibles about 1.9 times as broad as maximum width of mandible. Promesonotum strongly convex dorsally and sloping gradually to metanotal groove; mesopleuron not clearly demarcated from metapleuron; metapleural gland bulla relatively large, its maximum diameter about 2.7 times as long as distance between propodeal spiracle and metapleural gland bulla. Propodeum in profile with almost straight dorsal outline; propodeal junction acutely angulate, overhanging the declivitous face of propodeum; the declivity broadly and shallowly concave, encircled with a rim. Petiole subcylindrical, clearly longer than high, with its dorsal outline almost straight and elevated posteriad; subpetiolar process low, variable in shape (subtriangular to subrectangular). Postpetiole as long as petiole, convex dorsally and slightly elevated posteriorlly.

Head and gaster entirely smooth and shiny. Mandible very finely striate. Antennal scape supficially reticulate but shiny. Promesonotum reticulate with smooth and shiny bottoms except for anteriormost portion punctate and small area on dorsum smooth and shiny; upper portion of mesopleuron and upper portion of metapleuron with longitudinal rugae; lower portion of mesopleuron reticulate; propodeum entirely reticulate; in addition lateral face of propodeum with 2-3 longitudinal rugae. Petiole and postpetiole entirely reticulate. Legs entirely smooth and shiny except basal portion of femora superficially microreticulate.

Head and mesosoma dorsally with relatively sparse standing hairs mixed with sparse shorter hairs; longest pronotal hair 0.15–0.18 mm long. Head including antennal scape reddish brown; mandible, mesosoma, petiole, and postpetiole dark reddish brown; gaster and legs yellowish brown but gaster paler than legs.

Type Material

Holotype. INDONESIA: Worker from W. Java, Cibodas Botanical Garden, 28.XI.2009, leg. W. Jaitrong, WJT09-ID01 (MZB). Paratypes. Twenty-six workers, same data as holotype (BMHN, MCZC, MZB, SKYC, THNHM).

Etymology

The specific name refers to the range of the species, Sundaland (Sumatra, Borneo and Java).

References

• Jaitrong, W. & Yamane, S. 2013. The Aenictus ceylonicus species group (Hymenoptera, Formicidae, Aenictinae) from Southeast Asia. Journal of Hymenoptera Research 31:165-233.

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., and S. Yamane. 2013. The Aenictus ceylonicus species group (Hymenoptera, Formicidae, Aenictinae) from Southeast Asia. Journal of Hymenoptera Research 31: 165-233.