Cataulacus wissmannii

AntWiki - Where Ant Biologists Share Their Knowledge
Jump to: navigation, search
Cataulacus wissmannii
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Crematogastrini
Genus: Cataulacus
Species: C. wissmannii
Binomial name
Cataulacus wissmannii
Forel, 1894

Cataulacus-wissmanni MCZ001L.jpg

Cataulacus-wissmanni MCZ001D.jpg

Specimen Label

Synonyms

Nothing is known about the biology of Cataulacus wissmannii.

Identification

A member of the intrudens group. Cataulacus wissmanni may be confused with Cataulacus ebrardi, which is certainly closely related. Besides distribution, one of the best separating characters lies in the relative lengths of the alitrunk hairs. In ebrardi they are short and inconspicuous whilst in wissmannii they are very distinct. Also, in the former species the longitudinal rugation occupies only the anterior and posterior quarters of the length of the first gastral tergite, the intervening space being reticulate-punctate; whilst in wissmannii the puncturation on the tergite is usually limited to a patch in the middle of the disc. (Bolton 1974)

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Afrotropical Region: Kenya, Mozambique (type locality), South Africa, United Republic of Tanzania.

Distribution based on AntMaps

AntMapLegend.png

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

Worker

Nomenclature

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

  • wissmannii. Cataulacus wissmannii Forel, 1894b: 78 (w.) MOZAMBIQUE. Santschi, 1937a: 61 (q.). Senior synonym of durbanensis, linearis, otii: Bolton, 1974a: 51.
  • otii. Cataulacus wissmanni r. otii Forel, 1901d: 304 (w.q.) SOUTH AFRICA. Raised to species: Santschi, 1914e: 26; Arnold, 1917: 401. Junior synonym of wissmannii: Bolton, 1974a: 51.
  • durbanensis. Cataulacus micans r. durbanensis Forel, 1914d: 219 (w.) SOUTH AFRICA. Arnold, 1917: 395 (q.m.). Junior synonym of wissmannii: Bolton, 1974a: 51.
  • linearis. Cataulacus wissmanni st. linearis Santschi, 1914b: 109, fig. 17 (w.) KENYA. Junior synonym of wissmannii: Bolton, 1974a: 51.

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 3.8 – 5.2, HL 0.96 – 1.20, HW 0.96 – 1.20, CI 98 - 104, EL 0.44 – 0.50, OI 41 - 45, IOD 0.74 – 0.90, SL 0.48 – 0.60, SI 50 - 53, PW 0.78 – 1.02, AL 1.06 – 1.50, MTL 0.56 – 0.66 (10 measured).

Occipital crest absent, the two surfaces meeting in an obtuse angle. Occipital corners dentate, with a second short tooth internal to them upon the occipital margin. Sides of head behind eyes strongly convex and denticulate. Sides of pronotum marginate and denticulate, similarly the margins of both the mesonotum and propodeum with denticles. Propodeum bispinose. Mesokatepisternal tooth variously developed; in most individuals large and conspicuous but variable in size even in series from a single nest. Subpetiolar process simple, often without a differentiated posteroventral angle. Subpostpetiolar process weakly developed or virtually absent. First gastral tergite not marginate laterally.

Dorsum of head reticulate-rugose, the rugae usually emphasised in a longitudinal direction, with the interspaces weakly reticulate-punctate. Dorsal alitrunk usually similarly but more finely sculptured except for the propodeum where the longitudinal rugae are more strongly developed. Middle of disc of mesonotum often with the reticulation diminished and the reticulate-punctate sculpturation clearly visible. Petiole and postpetiole longitudinally rugose. First gastral tergite very strongly and often coarsely longitudinally rugose, occasionally throughout its length but more usually with the rugae broken in the middle of the disc and replaced by a fine reticulate-puncturation. All dorsal surfaces with numerous, very conspicuous, relatively long, simple hairs.

Queen

Bolton (1974) - TL 5.4 – 6.0, HL 1.14 – 1.22, HW 1.10 – 1.22, CI 97 – l00, EL 0.48 – 0.50, OI 41 -43, IOD 0.84 - 0.90, SL 0.54 – 0.62, SI 49 - 51, PW 1.02 – 1.10, AL 1.50 – 1.76, MTL 0.62 – 0.72 (2 measured).

As worker but with the denticulation of the sides of the head behind the eyes and the margins of the alitrunk reduced, on the latter to very small, triangular prominences. Propodeal spines short, blunt.

Type Material

Bolton (1974):

Holotype worker, MOZAMBIQUE: 9.xi.1890 (A. Muller) (MHN, Geneva) [examined].

Cataulacus wissmanni race otii Syntype workers, female, SOUTH AFRICA: Natal, Durban (Haviland) (MHN, Geneva) [examined].

Cataulacus wissmanni st. linearis Syntype workers, KENYA: Voi, in the Wa-Taita (st. no. 60), 600 m, and Mbuyuni, in Pori (st. no. 63), iii. 1912 (Alluaud & Jeannel) (NM, Basle) [examined].

Cataulacus micans race durbanensis Holotype worker, SOUTH AFRICA: Natal, Durban, 15.i.19I4 (G. Arnold) (MHN, Geneva) [examined].

References