Aenictus gonioccipus

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

So far this species has been known only from the type locality located in the lowland (100m alt.).

Identification

A member of the ceylonicus species group. Jaitrong and Yamane (2013) - Aenictus gonioccipus is a distinct species and can be separated from the other members of the group by having the posterolateral corner of head in profile angulated and nearly right-angled (corner is rounded in the other species).

Keys including this Species

Distribution

Sulawesi

Distribution based on Regional Taxon Lists

Indo-Australian Region: Indonesia (type locality).

Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Biology

Little is known about the biology of Aenictus gonioccipus. 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 New General Catalogue, a catalogue of the world's ants.

  • gonioccipus. Aenictus gonioccipus Jaitrong & Yamane, 2013: 190, figs. 9A-C (w.) INDONESIA.

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 paratypes, n = 5). TL 3.05–3.25 mm; HL 0.63–0.65 mm; HW 0.60–0.63 mm; SL 0.50–0.53 mm; ML 1.05–1.08 mm; PL 0.25–0.28 mm; CI 96; SI 83–88.

Head in full-face view slightly longer than broad, sides weakly convex and posterior margin almost straight; occipital margin bearing a distinct carina; with head in profile occipital corner angulate, nearly right-angled. Antennal scape reaching 2/3 of head length. Frontal carina relatively short, not reaching the level of posterior margin of torulus. Parafrontal ridge incomplete. Anterior clypeal margin concave, lacking denticles and concealed by curved anterior extension of frontal carina. Masticatory margin of mandible with large acute apical tooth followed by a medium-sized subapical tooth, 4–5 denticles, and a medium-sized basal tooth; basal margin weakly concave. Maximum width of gap between anterior clypeal margin and mandibles about 2.3 times as broad as maximum width of mandible. Promesonotum strongly convex dorsally and sloping gradually to metanotal groove that is indistinct; mesopleuron not clearly demarcated from metapleuron. Propodeum in profile with weakly convex dorsal outline; propodeal junction developed into a high, thin transverse ridge, which in profile appears a large, acute tooth overhanging propodeal declivity; the declivity shallowly concave, and encircled with a rim; metapleural gland bulla relatively small, its maximum diameter about 2.1–2.5 times as long as distance between propodeal spiracle and metapleural gland bulla. Petiole subsessile, almost as long as high but its node short, with dorsal outline elevated posteriorly; subpetiolar process generally very low, subrectangular with its anteroventral and posteroventral corners angulate, and margin between the corners almost straight. Postpetiole slightly longer than petiole, with its dorsal outline convex.

Head and gaster smooth and shiny; basal half of antennal scape densely micro-reticulate but apical half superficially microreticulate and shiny; mandible finely striate. Promesonotum smooth and shiny except for anteriormost portion reticulate and posteriormost portion punctate; mesopleuron, metapleuron, and propodeum entirely reticulate; in addition, mesopleuron with 4–5 longitudinal rugae. Petiole entirely reticulate; postpetiole reticulate (the reticulation weaker than in petiole) except its dorsum smooth and shiny. Basal 1/3 and apical 1/3 of femora sculptured, median swollen area smooth and shiny; tibiae microreticulate, partly smooth and shiny.

Head and mesosoma dorsally with relatively sparse standing hairs mixed with dense decumbent hairs; longest pronotal hair 0.28–0.30 mm long. Head and gaster reddish brown; antenna, mesosoma, petiole and postpetiole dark reddish brown; legs reddish brown to dark reddish brown.

Type Material

Holotype. INDONESIA: Worker from Sulawesi, Minasha Prov., Dumoga Bone N.P., E-Side, vic. Duluduo, 0˚35'N 124˚54'E, 100 m alt., 4-9. XII.2000, leg. A. Schulz, 598 (MHMW). Paratypes. Four workers, same data as holotype (MHMW).

Etymology

The specific name refers to the angulated occipital corner seen in profile.

References