Cataulacus reticulatus

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Cataulacus reticulatus
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Crematogastrini
Genus: Cataulacus
Species: C. reticulatus
Binomial name
Cataulacus reticulatus
Smith, F., 1857

Cataulacus reticulatus P casent0280799.jpg

Cataulacus reticulatus D casent0280799.jpg

Specimen Label

Synonyms

Nothing is known about the biology of Cataulacus reticulatus.

Identification

The true affinity of Cataulacus reticulatus does not lie with Cataulacus granulatus but with the species of the taprobanae group, particularly with Cataulacus praetextus, Cataulacus catuvolcus and Cataulacus chapmani, from which it is separable by the characters given in the key (Bolton 1974).

Keys including this Species

Distribution

Known from Malaysia (East and West).

Distribution based on Regional Taxon Lists

Indo-Australian Region: Borneo (type locality), Indonesia, Malaysia.


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.

  • minor. Cataulacus reticulatus var. minor Smith, F. 1857a: 81 (w.) BORNEO. Junior synonym of reticulatus: Bolton, 1974a: 82.
  • reticulatus. Cataulacus reticulatus Smith, F. 1857a: 81, pl. 2, fig. 8 (w.) BORNEO. Junior synonym of granulatus: Dalla Torre, 1893: 138; Wheeler, W.M. 1919e: 92. Revived status as species: Donisthorpe, 1932c: 451. Senior synonym of minor: Bolton, 1974a: 82.

The following notes on F. Smith type specimens have been provided by Barry Bolton (details):

Cataulacus reticulatus

Holotype worker in Oxford University Museum of Natural History. Labelled “SAR. 5.”

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) - Holotype. TL 4.2, HL 1.06, HW 1.26, CI 119, EL 0.40, OI 32, IOD 0.92, SL 0.54, SI 43, PW 0.98, AL not measurable, MTL 0.60

Bolton 1974 fig 35-37

Occipital crest complete, the median portion raised into a low, posteriorly projecting ridge; the crest without denticles. Sides of head behind eyes crenulate-denticulate, terminating in a small triangular tooth at the occipital corners. Preocular tooth triangular, the frontal carinae in front of this at first shallowly concave, then convex over the antennal insertions. Frontal groove absent. Sides of pronotum with a marginate, subrectangular expansion which begins a short distance behind the anterior pronotal border. Sides of mesonotum convex, angular, separated from the propodeum by a distinct V-shaped impression. Propodeum behind this notch with a free anterior margin at each side, the lateral margins extremely shallowly concave and continuous with the outer margins of the spines. Propodeal spines long, well developed, broad at the base and tapering to an acute apex. Lateral borders of all constituents of the alitrunk neither crenulate nor denticulate; the dorsum devoid of sutures or sutural impressions. Petiole in profile with the anterior and posterior faces sloping and convergent dorsally so that there is no separated dorsal surface to the segment. Dorsum of postpetiole low and rounded. Subpetiolar process simple, with an acute posteroventral angle. Subpostpetiolar process low and subrectangular. First gastral tergite longer than broad, length ca 1.50, maximum width ca 1.28, the sides convex and narrowing posteriorly. Basal corners marginate, the margination scarcely extending onto the sides.

Entirety of dorsum of head and alitrunk with a fine rugoreticulum, the interspaces of which are finely and densely reticulate-punctate. First gastral tergite similarly but much more finely sculptured. Propodeal declivity predominantly reticulate-punctate with only a few very faint rugulae; the anterior face of the petiole similarly sculptured.

Erect hairs virtually absent, present only on the mandibles and antennal scapes. A few (four or five) very short, blunt hairs project beyond the margins of the frontal carinae in dorsal view; otherwise the margins of the head and alitrunk are without projecting hairs although one or two minute, flattened hairs may be present near the margins themselves. First gastral tergite without hairs; some are present on the sternites.

Type Material

Bolton (1974):

Holotype worker, BORNEO: Sarawak (A. R. Wallace) (UM, Oxford) [examined].

Cataulacus reticulatus var. minor Holotype worker, BORNEO: Sarawak (A. R. Wallace) (presumed lost).

References

  • Bolton, B. 1974a. A revision of the Palaeotropical arboreal ant genus Cataulacus F. Smith (Hymenoptera: Formicidae). Bull. Br. Mus. (Nat. Hist.) Entomol. 30:1-105. (page 82, Senior synonym of minor)
  • Dalla Torre, K. W. von. 1893. Catalogus Hymenopterorum hucusque descriptorum systematicus et synonymicus. Vol. 7. Formicidae (Heterogyna). Leipzig: W. Engelmann, 289 pp. (page 138, Junior synonym of granulatus)
  • Donisthorpe, H. 1932c. On the identity of Smith's types of Formicidae (Hymenoptera) collected by Alfred Russell Wallace in the Malay Archipelago, with descriptions of two new species. Ann. Mag. Nat. Hist. 10(10): 441-476 (page 451, Revived status as species)
  • Smith, F. 1857a. Catalogue of the hymenopterous insects collected at Sarawak, Borneo; Mount Ophir, Malacca; and at Singapore, by A. R. Wallace. [part]. J. Proc. Linn. Soc. Lond. Zool. 2: 42-88 (page 81, pl. 2, fig. 8 worker described)
  • Wheeler, W. M. 1919f. The ants of Borneo. Bull. Mus. Comp. Zool. 63: 43-147 (page 92, Junior synonym of granulatus)