Aenictus piercei

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Aenictus piercei
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Dorylinae
Genus: Aenictus
Species: A. piercei
Binomial name
Aenictus piercei
Wheeler, W.M. & Chapman, 1930

Aenictus piercei casent0281961 p 1 high.jpg

Aenictus piercei casent0281961 d 1 high.jpg

Specimen Labels

Little is known about the bionomics of A. piercei. Nothing is mentioned by Wheeler (1930), however, judging from the hitherto known localities (Negros and Mindanao) (see Wilson 1964) this species inhabits lowland (15-600 m) and is probably restricted to the Philippines. Wilson (1964) cited India, Solon (ca. 1400 m), as a locality of A. piercei, but the identification should be reconfirmed.

Identification

A member of the javanus species group. This species is most similar to Aenictus duengkaei (see under A. duengkaei for differences).

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Indo-Australian Region: Philippines (type locality).
Oriental Region: India.
Palaearctic Region: China.

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 piercei. 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 58-63

Nomenclature

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

  • piercei. Aenictus (Aenictus) piercei Wheeler, W.M. & Chapman, in Wheeler, W.M. 1930g: 209, fig. 7 (w.) PHILIPPINES. See also: Wilson, 1964a: 474; Jaitrong & Yamane, 2012: 63.

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

Description

Worker

Wilson (1964) - Dumaguete: HW 0.46 mm, HL 0.51 mm, SL 0.27 mm. (Syntype: HW 0.44 mm; only HW could be measured in this specimen). Antenna 10-segmented; scape exceptionally short and incrassate. Mandibles narrow, 3- or 4-toothed; on closure, not separated by a gap from the anterior clypeal border. Clypeus convex, entire, unarmed. Parafrontal ridge lacking. Occiput very feebly convex. Basal face of propodeum straight. Propodeal junction evenly rounded. Femora incrassate, a distinctive character. Subpetiolar process proportionately very large, consisting of a symmetrical, downward directed lobe surmounted by a flange whose major angle is about 80° and projects posteriorly. Pilosity moderately abundant; length of longest pronotal hairs about 0.10 mm.

Head shining. Pronotum shining; remainder of mesosoma microreticulate (reticular diameters about 0.008 mm), dorsum feebly shining and sides microreticulate and subopaque. Concolorous medium yellow.

Jaitrong & Yamane (2012) - Lectotype: TL 2.15 mm; HL 0.53 mm; HW 0.48 mm; SL 0.28 mm; ML 0.70 mm; PL 0.20 mm; CI 90; SI 58.

Paralectotypes (n = 2): TL 2.15 mm; HL 0.53-0.58 mm; HW 0.48-0.50 mm; SL 0.28-0.33 mm; ML 0.70-0.83 mm; PL 0.20-0.23 mm; CI 87-90; SI 58-65.

Head in full-face view slightly longer than broad, subrectangular, with sides feebly convex and posterior margin almost straight; seen in profile occipital corner of head rounded. Antennal scape reaching midlength of head; antennal segment II longer and narrower than each of III–VI; terminal segment almost as long as VII+VIII+IX and 1.9 times as long as broad. Anterior margin of clypeus bearing 9-10 denticles (this observation is based on the single non-type worker, since in the lectotype mouth parts are buried in glue and the head of the paralectotype was missing). Masticatory margin of mandible with 3 acute teeth including large apical tooth; basal margin lacking denticles. Promesonotum in profile almost flat dorsally; in profile propodeum almost flat dorsally; propodeal junction angulate, right-angled; declivity of propodeum nearly flat, with blunt lateral carinae, but not demarcated basally by a transverse carina. Petiole almost as long as high, its dorsal outline convex; subpetiolar process well developed, subrectangular, its ventral margin slightly convex and longer than posterior margin; postpetiole almost as long as petiole.

Head including antennal scape entirely smooth and shiny. Mandible finely striate except along masticatory and outer margins. Pronotum entirely smooth and shiny except for anteriormost part microreticulate; mesonotum smooth and shiny; mesopleuron, metapleuron and propodeum microreticulate. Petiole entirely microreticulate. Postpetiole microreticulate except for a small smooth and shiny area on dorsal surface.

Head and mesosoma dorsally with relatively sparse standing hairs mixed with sparse short hairs; longest pronotal hairs 0.09-0.10 mm long. Entire body yellowish brown or reddish brown; legs palest.

Type Material

Described from two specimens taken by Dr. W. D. Pierce at Cadiz, P. I.

Jaitrong & Yamane (2012) - Two syntype workers on a pin, the Philippines, Negros, Cadiz, 2.VI.1924, leg. Dr. Pierce (Museum of Comparative Zoology, examined). The worker located below on the pin is selected as the lectotype.

References

  • Chapman, J. W.; Capco, S. R. 1951. Check list of the ants (Hymenoptera: Formicidae) of Asia. Monogr. Inst. Sci. Technol. Manila 1: 1-327 (page 11, checklist)
  • Jaitrong, W. & Yamane, S. (2012) Review of the Southeast Asian species of the Aenictus javanus and Aenictus philippinensis species groups (Hymenoptera, Formicidae, Aenictinae). ZooKeys 193: 49–78, doi: 10.3897/zookeys.193.2768.
  • Wheeler, W. M. 1930j. Philippine ants of the genus Aenictus with descriptions of the females of two species. J. N. Y. Entomol. Soc. 38: 193-212 (page 209, fig. 7 worker described)
  • Wilson, E. O. 1964a. The true army ants of the Indo-Australian area (Hymenoptera: Formicidae: Dorylinae). Pac. Insects 6: 427-483 (page 474, see also)