Aenictus rabori

AntWiki - Where Ant Biologists Share Their Knowledge
Jump to: navigation, search
Aenictus rabori
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Dorylinae
Genus: Aenictus
Species: A. rabori
Binomial name
Aenictus rabori
Chapman, 1963

Aenictus rabori casent0217384 p 1 high.jpg

Aenictus rabori casent0217384 d 1 high.jpg

Specimen Labels

A. rabori is known only from the type locality. The colony observed by Chapman was foraging in a garden at 1,080 m in elevation (Chapman 1963).

Identification

A member of the philippinensis species group. This species is closely related to Aenictus pangantihoni. See under A. pangantihoni for details.

Keys including this Species

Distribution

Philippines (Negros Island)

Distribution based on Regional Taxon Lists

Indo-Australian Region: Philippines (type locality).

Distribution based on AntMaps

AntMapLegend.png

Distribution based on AntWeb specimens

Check data from AntWeb

Biology

Little is known about the biology of Aenictus rabori. 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 76-83

Nomenclature

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

  • rabori. Aenictus (Aenictus) rabori Chapman, 1963: 249, fig. 2 (w.) PHILIPPINES. See also: Wilson, 1964a: 476; Jaitrong & Yamane, 2012: 74.

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) - Syntypes: Worker selected at random: HW 0.78 mm, HL 0.83 mm, SL 0.62 mm; HW of remainder of long syntype series 0.82-0.84 mm. Antenna 10-segmented. Mandibles typical. Clypeus convex, entire unarmed. Parafrontal ridge about 0.17 mm. Occiput very feebly convex, lacking distinct collar. Mesonotum demarcated from mesopleuron by a conspicuous ridge; a striking character shared within the genus only by the sympatric philippinensis. In addition, mesonotum drops to metanotum through a short vertical face; this character is peculiar to rabori. Unlike rabori, metanotum is level with basal face of propodeum. Femora and tibiae distinctly thicker than in philippinensis. Propodeal junction acutely angulate. Subpetiolar process almost non-existent, consisting at most of a very low central convexity. Pilosity moderately abundant; length of longest pronotal hairs 0.15 mm.

Entire head shining. Pronotal dorsum shining; remainder of mesosoma microreticulate and opaque. Pedicel microreticulate, its dorsum shining; remainder subopaque. Color as in philippinensis.

Jaitrong & Yamane (2012) - Lectotype: TL 4.50 mm; HL 0.85 mm; HW 0.83 mm; SL 0.65 mm; ML 1.48 mm; PL 0.35 mm; CI 97; SI 79.

Paralectotype (n = 8): TL 4.35-4.45 mm; HL 0.83-0.88 mm; HW 0.78-0.83 mm; SL 0.63-0.65 mm; ML 1.48-1.50 mm; PL 0.35-0.38 mm; CI 94-97; SI 76-79.

Head in full-face view slightly longer than broad, with sides convex and posterior margin nearly straight, very weakly sinuate; occipital margin bearing a distinct carina; occipital corner of head with a protruding lobe (part of occipital carina). Antennal scape relatively short, reaching only 2/3 of head length; antennal segment II slightly longer than each of III-VI; terminal segment slightly shorter than VII+VIII+IX. Frontal carinae short fused at the level of antennal base to form a single carina and much extending beyond the level of the posterior margin of torulus, poorly developed in posterior half. Parafrontal ridge short, extending less than 1/3 of head length, 0.25-0.27 mm long, seen in profile weakly developed in posterior half. Masticatory margin of mandible with a large apical tooth followed by a series of 4-5 denticles, which gradually reduce in size toward basal angle of mandible. Promesonotum in profile weakly convex dorsally and sloping gradually to metanotal groove; metanotal groove distinct and deep; upper portion of meso- and meta-pleuron impressed, much lower than promesonotum. Declivity of propodeum shallowly concave, encircled with a distinct rim that protrudes posteriad. Petiole subsessile, distinctly longer than high; subpetiolar process almost absent; postpetiole slightly shorter than petiole and almost as long as high, with its node rounded dorsally. Legs relatively short, seen from side with greatly swollen femora.

Head entirely smooth and shiny, except for hair pits, area on the side of head anterior to occipital corner with superficial reticulation; mandible extensively smooth and shiny except for hair pits; antennal scape superficially shagreened. Pronotum smooth and shiny, except for its anteriormost portion reticulate, narrow lateral margins distinctly reticulate, reaching back to posterior margin; mesonotum smooth and shiny; mesopleuron, metapleuron and propodeum densely punctuate/reticulate mixed with some rugae, mat except antero-ventral parts of meso- and metapleuron slightly shiny. Petiole microreticulate with dorsum more weakly sculptured; dorsum of postpetiole extensively smooth and shiny but other parts more or less reticulate. Femora entirely superficially reticulate and shiny; tibiae superficially shagreened partly smooth and shiny.

Head and mesosoma dorsally with relatively sparse long standing hairs; longest pronotal hair 0.25-0.27 mm long. Head, antennae, legs, and gaster yellowish brown; mandible, mesosoma, petiole, and postpetiole reddish brown.

Type Material

Jaitrong & Yamane (2012) - Nine syntype workers (two on each of three pins, three on another) from Philippines, Negros, Horns of Negros, 1,080 m (Museum of Comparative Zoology, examined). One worker among them (top on a pin) is selected as lectotype.

References