Aenictus brevinodus

AntWiki - Where Ant Biologists Share Their Knowledge
Jump to navigation Jump to search
Aenictus brevinodus
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Dorylinae
Genus: Aenictus
Species: A. brevinodus
Binomial name
Aenictus brevinodus
Jaitrong & Yamane, 2011

Aenictus brevinodus casent0903684 p 1 high.jpg

Aenictus brevinodus casent0903684 d 1 high.jpg

Specimen Labels

This species occurs in lowland and highland forests. Workers of the type series were found raiding on low vegetation along a road.

Identification

A member of the laeviceps species group. Jaitrong and Yamane (2011) - A. brevinodus is quite similar to Aenictus hodgsoni. However, it has fewer standing hairs on the mesosomal dorsum (less than 10 hairs in A. brevinodus; more than 20 in A. hodgsoni); the petiolar node is clearly shorter than high (almost as long as high or slightly longer than high in A. hodgsoni); and the legs are entirely smooth and shiny (femora extensively superficially reticulate and shiny, and tibiae very finely reticulate in the latter).

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Indo-Australian Region: Indonesia (type locality), Sulawesi.

Distribution based on AntMaps

AntMapLegend.png

Distribution based on AntWeb specimens

Check data from AntWeb

Biology

Little is known about the biology of Aenictus brevinodus. 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.

  • brevinodus. Aenictus brevinodus Jaitrong & Yamane, 2011: 33, figs. 46-48 (w.) INDONESIA (Sulawesi).

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

Description

Worker

Measurements. Holotype and paratypes (n = 7): TL 3.65–3.75 mm; HL 0.78–0.83 mm; HW 0.70–0.73 mm; SL 0.65–0.70 mm; ML 1.15–1.20 mm; PL 0.23–0.25 mm; CI 88–91; SI 93–97.

holotype and paratypes - Head in full-face view rather oval, slightly longer than broad, with sides distinctly convex and posterior margin almost straight or weakly convex; occipital carina weak but complete. Antennal scape relatively short, in full-face view not reaching posterolateral corner of head; antennal segments II–X each longer than broad; II almost as long as each of III–V; terminal segment (X) almost as long as VII+VIII+IX. Frontal carina short, slightly extending beyond posterior margin of torulus; parafrontal ridge absent. Anterior margin of clypeus slightly convex, bearing 8 denticles. Masticatory margin of mandible with a large apical tooth followed by a medium-sized subapical tooth, 3–4 denticles, a medium-sized subbasal tooth and a smaller basal tooth (the latter two widely separated from each other); basal margin lacking denticles. Promesonotum in profile strongly convex and forming a dome, mesonotum sloping to metanotal groove; propodeum distinctly lower than promesonotum, with its dorsal outline almost straight; propodeal junction rather sharply to roundly angulate; declivity of propodeum seen in profile vertical, almost straight or feebly concave, irregularly sculptured, without a distinct rim separating the declivity from other parts. Petiole subsessile and rather short, its node slightly shorter than high; subpetiolar process hook-like, variable in size, with apex directed downward and backward; postpetiole distinctly larger than petiole.

Entire head including antennal scape smooth and shiny. Mandible very finely striate except along masticatory margin and near base. Pronotum entirely smooth and shiny except for anteriormost portion punctate; dorsa of both mesothorax and propodeum extensively smooth; small posterior portions of mesothorax and propodeum, and lower part of metapleuron irregularly punctate or rugulose. Petiole and postpetiole entirely smooth and shiny. Legs entirely smooth and shiny.

Vertex with a pair of long standing hairs and very sparse short hairs. Mesosoma dorsally with relatively sparse standing hairs mixed with very sparse short hairs over the surface; longest pronotal hair 0.20–0.23 mm long. Entire body dark reddish-brown. Typhlatta spot located anterior to occipital corner.

Type Material

Holotype worker from Indonesia, S. Sulawasi, Laiya, Labbang, 24 I 2010, Sk. Yamane leg., CE10-SKY-15 (Bogor Zoological Museum). Fourty-five paratype workers, same data as holotype (Ant Museum, The Natural History Museum, SKY Collection, Natural History Museum of the National Science Museum).

Etymology

The specific name means the short petiole.

References

  • Jaitrong, W. & Yamane, S. 2011. Synopsis of Aenictus species groups and revision of the A. currax and A. laeviceps groups in the eastern Oriental, Indo-Australian, and Australasian regions (Hymenoptera: Formicidae: Aenictinae). Zootaxa, 3128, 1–46.