Aenictus asantei

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This species is probably a column raider and was found collecting immatures of a Pheidole species in coastal scrub and grassland habitat.

Aenictus asantei
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Dorylinae
Genus: Aenictus
Species: A. asantei
Binomial name
Aenictus asantei
Campione, Novak & Gotwald, 1983

Identification

Campione et al 1983-2 Aenictus-asantei.jpg

Distribution

Distribution based on Regional Taxon Lists

Afrotropical Region: Ghana (type locality), Nigeria.

Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Biology

Campione et al. (1983) - Behavioral observations on A. asantei were published previously (Gotwald 1976). The species (species A in Gotwald [1976]) was observed on four occasions (colonies GC-027, GC-035, GC-037, GC-047) in coastal scrub and grassland at Legon, Ghana, and once (colony GC-049) crossing a path between plots of cocoa, Theobroma cacao L., in the moist, semideciduous forest re­gion at Jukwa, Ghana. All five colonies were collected in heavily cultivated habitats. The four colonies found at began, the type-locality, were in columns moving near or in plots planted with cassava, Manihot esculenta Crantz, in the University of Ghana farm system.

A. asantei is probably a column raider (a column raid consists of a system of branching columns that usually terminate in small groups of advancing workers engaged in foraging activities), although on two occasions (colonies GC-035 and GC-037) the workers were traveling in a series of anastomosing columns that merged to form a single base column, reminiscent of the swarm raiding patterns of the driver ants of the army ant genus Doryus. In these two cases, the workers were traveling unidirectionally toward the base column, presumably toward the colony nest. The base columns varied from one to four workers in width, and some workers in each carried prey. Each trunk column entered a hole in the soil. The column of colony GC-037 was lined on both sides with clustered workers for the last 10 cm before the column made its subterranean descent. Colonies GC-027 and GC-049 were each observed as columns consisting of a single file of workers. The prey collected from colony GC-037 consisted of immature forms of the ant Pheidole sp. and included 24 worker pupae and 3 larvae. Although colony GC-047 was emigrating, several workers carried prey, all adults of Pheidole. The prey items included one queen, two workers, three worker heads, and one mesosoma.

The emigrating column of colony GC-047 was discovered at 0950 h. A detailed description of the emigration can be found in Gotwald (1976).

Castes

Nomenclature

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

  • asantei. Aenictus asantei Campione, Novak & Gotwald, 1983: 873, 7 figs. (w.q.) GHANA.

Description

Worker, composite description. Habitus as in Fig.A and B; total length 3.47-3.89 mm; head, alitrunk, waist, and gaster dark reddish brown to reddish orange;legs and antennae orange-brown to yellow-orange; bul­lae of metapleural glands yellow, especially conspicuous in darkly pigmented individuals. Pilosity moderately abundant, consisting of erect to suberect setae. Head as in Fig. JC; head length 0.63-0.77 mm; head width 0.63-0.72 mm; cephalic index (HW/HL X 100) 93.5-107.9. Head glossy, without obvious punctures; parafrontal ridges (elevated lines extending longitudi­nally from clypeus laterad to the antenna! fossae) well developed, each terminating in a minute spine. Frontal carinae expanded anteriorly to form thin flanges pro­jecting dorsally; clypeus bearing distinct serial teeth (Fig. lC and 3 A and B); occipital collar present; eyes absent. Antenna 10-segmented, scape length 0.54-0.63 mm. Mandible flattened, linear, striolate, with sharp apical tooth; subapical teeth absent, although some denticles. may be present (Fig: 2B). Labrum bilobed with smoothly rounded median cleft (Fig. 2A); maxillary palpus two-segmented (Fig. 2C); lateral shoulder of stipes bearing three stout setae (Fig. 2C); stipes without transverse stipital groove; galea crown flattened, invested with numerous setae (Fig. 2C); maxillary comb typical (Fig. 2C); la­cinial apex bearing numerous, irregularly placed, fine . setae (Fig. 2C); labial palpus two-segmented (Fig. 20). Alitrunk as in Fig. I A and B and 3C; alitrunk length I. 10-1.26 mm; without conspicuous suturing. Pronotum glossy except for anterior dorsal slope, this densely punctate; posterior two-thirds of alitrunk subopaque with well-developed longitudinal rugae, especially on pleurae (Fig. 3C); propodeal junction marked by sharply pro­duced ridge extending laterally and bordering declivi­tous face of propodeum; declivitous face densely punctate. Petiole and postpetiole as in Fig. 10; waist (petiole plus postpetiole) length 0.63-().68 mm; petiole node length 0.29-0.36 mm, width 0.18-0.27 mm; postpetiolar node length 0.27-0.36 mm, width 0.20-0.27 mm. Waist opaque, densely punctate; subpetiolar process triangular with rounded apex, usually directed ventrally or poste­riorly (Fig. 10).Gaster as in Fig. I A and B; gaster length 1.13-1.26 mm. Gaster glossy, lacking obvious punctures. Tarsal claws simple

Etymology

This species is named for the Asante people of Ghana.

References