Aenictus brevicornis

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Aenictus brevicornis
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Dorylinae
Genus: Aenictus
Species: A. brevicornis
Binomial name
Aenictus brevicornis
(Mayr, 1879)

Aenictus brevicornis casent0281955 p 1 high.jpg

Aenictus brevicornis casent0281955 d 1 high.jpg

Specimen Labels

Nothing is known about the biology of Aenictus brevicornis.

Identification

Keys including this Species

Distribution

India: Assam and Agra south to Calcutta in the east and Calicut and Bangalore on the peninsula.

Distribution based on Regional Taxon Lists

Oriental Region: Bangladesh, India (type locality), Vietnam.

Check distribution from AntMaps.

Distribution based on specimens

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

Biology

Little is known about the biology of Aenictus brevicornis. 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 51-57

Nomenclature

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

  • brevicornis. Typhlatta brevicornis Mayr, 1879: 669 (w.) INDIA. [Typhlatta brevicornis Smith, F. 1873: ix. Nomen nudum, attributed to Mayr.] Imai, Brown, et al. 1984: 8 (k.). Combination in Aenictus: Dalla Torre, 1893: 7. See also: Wilson, 1964a: 451.

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) - Lectotype (herein designated from a syntype in the collection of the Naturhistorisches Museum, Vienna). HW 0.53 mm, HL 0.60 mm, SL 0.35 mm, Sl 66. Antenna 10-segmented. Mandible very narrow, bearing 3 large teeth; in closure, leaving a gap between its posterior border and the anterior clypeal border. Anterior clypeal border flat in the center, entire, armed with 7 well-developed teeth. Parafrontal ridge absent. Occiput convex, lacking collar. Propodeal faces seen in side view straight, approaching one another at an angle of about 100°; but their junction evenly rounded. Subpetiolar process a flat, forward-directed lobe surmounted by a subtriangular flange whose apex is posteriorly directed. Pilosity extremely abundant overall, more than in any other Indo-Australian member of the genus; length of the longest pronotal hairs about 0.20 mm.

Head shining. Mesopleuron, metapleuron, and propodeum microreticulate, opaque; remainder shining. Pedicel microreticulate overall; dorsa feebly shining, remainder opaque. Brownish yellow; head and alitrunk a shade darker than the rest.

Paratype: HW 0.51 mm, HL 0.60 mm, SL 0.35 mm, Sl 69. Very similar to the lectotype, but differing greatly in the shape of the subpetiolar process: this structure is much smaller, and the ventral flange is directed anteriorly (fig. 53). This difference between the 2 syntypes examined induced me to designate a lectotype, on the chance that 2 species are represented in the original Mayr series.

Type Material

Type locality: Calcutta, India.

References

  • Dalla Torre, K. W. von. 1893. Catalogus Hymenopterorum hucusque descriptorum systematicus et synonymicus. Vol. 7. Formicidae (Heterogyna). Leipzig: W. Engelmann, 289 pp. (page 7, Combination in Aenictus)
  • Imai, H. T.; Baroni Urbani, C.; Kubota, M.; Sharma, G. P.; Narasimhanna, M. H.; Das, B. C.; 1984. Karyological survey of Indian ants. Jpn. J. Genet. 59: 1-32 (page 8, karyotype described)
  • Mayr, G. 1879. Beiträge zur Ameisen-Fauna Asiens. Verh. K-K. Zool.-Bot. Ges. Wien 28: 645-686 (page 669, worker described)
  • Smith, F. 1873. [Untitled. Introduced by: "Mr. F. Smith exhibited a further collection of ants sent by Mr. G. A. James Rothney, from Calcutta."]. Trans. Entomol. Soc. Lond. 1873:viii-ix. (page ix, Typhlatta brevicornis nomen nudum, attributed to Mayr.)
  • Tak, N. 2000b. Studies on ants (Formicidae) of Rajasthan - III. Banswara. Entomon 25: 97-101 (page 47, record for India)
  • Wilson, E. O. 1964a. The true army ants of the Indo-Australian area (Hymenoptera: Formicidae: Dorylinae). Pac. Insects 6: 427-483 (page 451, see also)