Aenictus minipetiolus

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

Known only from the type locality.

Identification

A member of the ceylonicus group. Jaitrong and Yamane (2013) - Aenictus minipetiolus is similar to Aenictus baliensis, Aenictus longicephalus and Aenictus wiwatwitayai (see under A. baliensis). It is a distinct species and is easily distinguished from the other species of the group by the almost entirely smooth and shiny body and the unique mandible (distal 2/3 of basal margin straight, proximal 1/3 concave).

Keys including this Species

Distribution

Lombok

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 minipetiolus. 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.

  • minipetiolus. Aenictus minipetiolus Jaitrong & Yamane, 2013: 203, figs. 14A-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 2.70–3.10 mm; HL 0.60–0.68 mm; HW 0.54–0.65 mm; SL 0.40–0.48 mm; ML 0.83–0.95 mm; PL 0.20–0.23 mm; CI 90–96; SI 72–74.

Head in full-face view subrectangular, slightly longer than broad, sides weakly convex, posterior margin feebly concave; occipital margin bearing a distinct carina. Antennal scape relatively short, not reaching 2/3 of head length. Frontal carina relatively short, reaching the level of posterior margin of torulus. Parafrontal ridge feeble and incomplete. Anterior clypeal margin almost straight, not concealed by curved anterior extension of frontal carina. Masticatory margin of mandible with large acute apical tooth followed by a medium-sized subapical tooth, 1-2 denticles, and a medium-sized basal tooth; basal margin bladed (distal 2/3 straight and proximal 1/3 sloping gradually to the base of mandible). Maximum width of gap between anterior clypeal margin and mandibles about 1.2 times as broad as maximum width of mandible. Promesonotum convex dorsally and sloping gradually to metanotal groove; mesopleuron relatively long, clearly demarcated from metapleuron by a groove; metapleural gland bulla relatively large, its maximum diameter about 1.6 times as long as distance between propodeal spiracle and metapleural gland bulla. Propodeum in profile with almost straight dorsal outline; propodeal junction angulate; declivity of propodeum flat, with blunt lateral carinae but not demarcated basally by a transverse carina. Petiole almost as long as high, node short, and dorsal outline convex; subpetiolar process low and short, its ventral outline convex. Postpetiole clearly larger than petiole, its dorsal outline slightly elevated posteriorly.

Head including mandible and antennal scape entirely smooth and shiny. Entire mesosoma smooth and shiny except for mesopleuron with relatively irregular longitudinal rugae; petiole and postpetiole entirely smooth and shiny.

Head and mesosoma dorsally with relatively sparse standing hairs; longest pronotal hair 0.23–0.25 mm long. Head, petiole, gaster, antennal scape, and legs yellowish brown; mesosoma reddish brown; mandible dark brown.

Type Material

Holotype. INDONESIA: Worker from Lombok, near Senaru, 27.X.1998, leg. I.K.T. Ginarsa, KT-100 (MZB). Paratypes. Four workers, same data as holotype (SKYC, THNHM).

Etymology

The specific name refers to the small petiole.

References