Cataulacus micans

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Cataulacus micans
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Crematogastrini
Genus: Cataulacus
Species: C. micans
Binomial name
Cataulacus micans
Mayr, 1901

Cataulacus micans casent0909228 p 1 high.jpg

Cataulacus micans casent0909228 d 1 high.jpg

Specimen Labels

Synonyms

Nothing is known about the biology of Cataulacus micans.

Identification

A member of the intrudens group. The worker is characterized by its very strongly developed mesokatepisternal tooth and the wealky sculptured, often polished gaster.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Afrotropical Region: South Africa (type locality).

Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Biology

Much of the information concerning the biology of Cataulacus species is anecdotal and fragmentary. Arnold (1917) wrote a succinct general overview of Cataulacus biology that still remains quite informative. Arnold reports "all the species of this genus are tree-ants, usually forming medium sized nests in hollow twigs and stems, or more rarely, under the bark. They are timid and slow-moving insects, often feigning death or dropping rapidly to the ground when disturbed. As Bingham has remarked in connection with this genus (Fauna Brit. India, Formicidae), these ants have the habit of wandering over the trunks of trees and the leaves in what appears to be a very aimless and languid manner. I have occasionally seen them breaking open the earthen tunnels constructed by termites over the trunks of trees and attack the inmates."

Bolton (1974) expands upon this earlier account - "All known Cataulacus species are arboreal or subarboreal nesters and they predominantly forage on the trees and shrubs in which the nests are situated. Very few appear to come down to ground level but in West Africa the small species Cataulacus pygmaeus and Cataulacus brevisetosus may be found foraging in leaf litter or crossing the ground to ascend a tree other than the one in which the nest is situated. The nests themselves are usually constructed in small hollow twigs or stems by the smaller species and in rotten branches or rotted portions of the tree trunk by the larger species. This is rather a generalization as some small species are known which nest in and under rotten bark (e.g. Cataulacus vorticus) and undoubtedly some of the larger forms will eventually be found inhabiting relatively small cavities in plants.

Various species of the genus in Africa are known to inhabit a variety of galls, acacias and bushes as well as large trees. Numerous species have been found nesting in, and have therefore been often collected from, cocoa in Africa. Some of these species are Cataulacus guineensis, Cataulacus pygmaeus, Cataulacus mocquerysi, Cataulacus egenus, Cataulacus vorticus, Cataulacus brevisetosus, Cataulacus kohli and Cataulacus theobromicola. Feeding habits in the genus are mostly unknown but the present author has noted C. guineensis tending aphids and small coccids.

On the plants ants of the genus Cataulacus often occur together with Oecophylla or species of Crematogaster, and appear to be mostly tolerated (at least they are not evicted) by the majority of these forms. Their defence against attackers of these genera lies primarily in their armoured exterior, but their ultimate escape reaction is to curl up and release their grip on the plant, falling to the ground and thus making their escape. The decision to remain immobile and present an armoured surface or to drop from the plant appears to depend upon the size or persistence of the aggressor; larger attackers usually precipitate the latter reaction, but it has also been noted as a result of persistent and unwanted attention by a series of workers of a small Crematogaster species.

The majority of species are forest-dwelling forms, with relatively few adapted to savannah or veldt conditions. Those which do, however, occur in these zones tend to be very successful in their chosen habitat and often possess a wide distribution. A few species are apparently able to exist in any region of Africa providing the basic essentials of nesting-site and food supply are met with, but on the whole the fauna may be divided into forest and non-forest forms."

Some species have nests that can be protected by a single worker's head, as its shape matches the nest entrance and forms an effective plug.

It has more recently been discovered that some species of Cataulacus are efficient gliders (Cataulacus erinaceus, Cataulacus guineensis, Cataulacus mocquerysi and Cataulacus tardus). Workers exhibit directed movement while in freefall that allows them to glide back to regain a hold on the same tree trunk. (Yanoviak et al. 2005, 2007, 2008)

Castes

Nomenclature

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

  • micans. Cataulacus rugosus subsp. micans Mayr, 1901b: 27 (w.q.m.) SOUTH AFRICA. Raised to species: Forel, 1914d: 219. Senior synonym of tristiculus: Bolton, 1974a: 46.
  • tristiculus. Cataulacus intrudens st. tristiculus Santschi, 1919b: 237 (w.q.m.) SOUTH AFRICA. Junior synonym of micans: Bolton, 1974a: 46.

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

Description

Worker

Bolton (1974) - TL 4.2 – 4.7, HL 1.02 -1.18, HW 1.04 – 1.12, CI 100 - 102, EL 0.42 – 0.44, OI 39 - 40, IOD 0.80 – 0.86, SL 0.54 - 0.56, SI 49 - 50, PW 0.82 – 0.92, AL 1.12 – 1.22, MTL 0.52 - 0.56 (3 measured).

Occipital crest not developed but the vertex separated from the occiput by an acute angle. Occipital corner dentate, the tooth flanked by a smaller denticle on the occipital margin. Sides of head behind eyes denticulate. Pronotum marginate, the edges weakly denticulate, the denticles not strongly developed, usually appearing as rather low, broadly triangular prominences. Sides of mesonotum and propodeum each with one or two denticles, the latter armed with a pair of spines. Mesokatepisternal tooth relatively very strongly developed, long, triangular and acute, projecting anterolaterally and visible with the alitrunk in dorsal view. Dorsal alitrunk without trace of sutures. First gastral tergite not marginate laterally.

Dorsum of head rather coarsely and closely longitudinally rugose; this sculpturation being derived from a rugoreticulum of which some cross-meshes are visible, though much less strongly developed than the longitudinal component. Interspaces superficially reticulate-punctate, somewhat shining. Sculpturation of dorsal alitrunk variable in intensity but basically of a fine, loose rugoreticulum on the pronotum, the cross-meshes of which tend to be lost on the mesonotum, resulting in a fine, longitudinal rugulation upon that segment. Interspaces everywhere finely and densely reticulate-punctate. Segments of pedical coarsely longitudinally rugose. First gastral tergite very finely sculptured, either with a fine superficial reticulation or reticulate-puncturation and usually with a few faint basigastric rugulae.

All dorsal surfaces of head and body with erect, stout, blunt hairs; those on the head may be very short and inconspicuous.

Queen

Bolton (1974) - TL 5.5, HL 1.22, HW 1.20, CI 99, EL 0.48, OI 43, IOD 0.88, SL 0.58, SI 48, PW 1.04, AL 1.54, MTL 0.66.

As worker, with the usual modifications of the alitrunk. Denticles of sides of head behind eyes reduced, the appearance crenulate. Pronotal margination irregular, with only two or three developed denticles. Mesokatepisternal tooth short and blunt. Propodeal spines short and blunt. Sculpturation of head and pronotum as worker, the mesoscutum sparsely longitudinally rugose, the mesoscutellum rather more coarsely rugose. Propodeal dorsum transversely rugose.

Male

Bolton (1974) - TL 4.6, HL 0.90, HW 0.96, CI 106, EL 0.38, OI 40, IOD 0.72, SL 0.50, SI 52, PW 0.84, AL 1.40, MTL 0.58.

Vertex rounding into occiput, the two surfaces not separated by an angle. Occipital corners dentate, sides of head behind eyes denticulate. Sides of pronotum weakly marginate, with one or two tuberculiform denticles. Anterior arms of notauli developed and crossribbed but tending to fade out medially, the posterior arm absent. In dorsal view the shape of the anterior arms tends to be broadly U-shaped rather than V-shaped. Propodeal spines short and blunt. Sculpturation of head as in worker but the longitudinal rugae fine and relatively widely separated. Alitrunk sculptured as female but on the propodeum the rugae diverge posteriorly towards the bases of the spines. Between the spines the rugae are transverse. Erect hairs present on all dorsal surfaces.

Type Material

Bolton (1974) :

Syntype workers, females, males, SOUTH AFRICA: Port Elizabeth, 1890 (Brauns) (NM, Vienna) [examined].

Cataulacus intrudens st. tristiculus Syntype workers, female, male, SOUTH AFRICA: Cape Province, Port Elizabeth, 1917 (T. Reese) (NM, Easle) [examined].

References