Aenictus schneirlai

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Aenictus schneirlai
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Dorylinae
Genus: Aenictus
Species: A. schneirlai
Binomial name
Aenictus schneirlai
Wilson, 1964

Aenictus schneirlai casent0905732 p 1 high.jpg

Aenictus schneirlai casent0905732 d 1 high.jpg

Specimen Labels

The (type) colony was found in rather open, somewhat disturbed lowland rain forest, bivouacked in the soil on the top of a low ridge. The bivouac cavities apparently had a single small entrance hole, and there was no evidence of recent excavation. The brood consisted entirely of pupae and packets of eggs. Hence, I interpret it as having been in the statary phase. When discovered, during the afternoon, there were no foraging columns leading from the nest. (Wilson 1964)

Identification

A member of the ceylonicus group.

Key to Aenictus species groups

Distribution

Distribution based on Regional Taxon Lists

Indo-Australian Region: New Guinea (type locality).

Check distribution from AntMaps.

Distribution based on specimens

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The above specimen data are provided by AntWeb. Please see Aenictus schneirlai for further details

Biology

Little is known about the biology of Aenictus schneirlai. 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.

Wilson 1964 Army Ant fig 45-50

Nomenclature

The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.

  • schneirlai. Aenictus schneirlai Wilson, 1964a: 479, figs. 49, 50 (w.) NEW GUINEA.

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

Description

Worker

Holotype: HW 0.63mm, HL 0.67mm, SL 0.56mm. Antenna 10-segmented. Mandible falciform, 3-toothed; in closure its posterior border separated from anterior clypeal border by a gap about 2 x as wide as maximum width of scape. Clypeus convex, deeply emarginate, and unarmed. Parafrontal ridge absent. Occiput convex, lacking a distinct collar. Basal face of propodeum evenly and gently convex. Propodeal junction acutely (80°) angulate. Subpetiolar process distinctive, consisting of a downward projecting lobe with a secondary anterior tooth and surmounted ventrally by a thin, tooth-like flange which is directed downward. Pilosity abundant; length of longest pronotal hairs 0.25 mm.

Head and mesosoma entirely microreticulate (reticular diameters about 0.01 mm) and subopaque. In addition mesopleuron, metapleuron, and propodeum bear about 16 longitudinal rugae. Pedicel microreticulate and opaque, except for postpetiolar dorsum, which is nearly smooth and feebly shining. Head, mesosoma, and pedicel rich medium reddish brown; gaster and appendages a contrasting light reddish brown.

Paratypes: Worker chosen at random: HW 0.68 mm, HL 0.69 mm, SL 0.60 mm. HW of remaining seven paratypes 0.62-0.68 mm. This series shows little variation in any character.

Type Material

Type locality: Bubia, 13 km NW of Lae, NE New Guinea (Wilson).

Etymology

This species is named after Dr T. C. Schneirla, the leading student of doryline biology.

References

  • Wilson, E. O. 1964a. The true army ants of the Indo-Australian area (Hymenoptera: Formicidae: Dorylinae). Pac. Insects 6: 427-483 (page 479, figs. 49, 50 worker described)