Cataulacus chapmani

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Cataulacus chapmani
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Crematogastrini
Genus: Cataulacus
Species: C. chapmani
Binomial name
Cataulacus chapmani
Bolton, 1974

Cataulacus chapmani P casent0900256h.jpg

Cataulacus chapmani D casent0900256.jpg

Specimen Label

Nothing is known about the biology of Cataulacus chapmani.

Identification

A member of the taprobanae group. Closely related to Cataulacus reticulatus and its immediate allies, Cataulacus chapmani is separated by its lack of an occipital crest, which is present in other species of the complex, The sculpturation of the alitrunk approximates closely to that of Cataulacus catuvolcus but this species has a marginate first gastral tergite as well as a distinct occipital crest. (Bolton 1974)

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Indo-Australian Region: Philippines (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.

  • chapmani. Cataulacus chapmani Bolton, 1974a: 75, fig. 30 (w.m.) PHILIPPINES.

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

Description

Worker

Holotype. TL 4.9, HL 1.14, HW 1.34, CI 118, EL 0.42, OI 31, IOD 1.08, SL 0.60, SI 45, PW 1.06, AL 1.34, MTL 0.66.

Bolton 1974 fig 30-34

Occipital crest absent, the vertex not separated from the occiput. Sides of head behind eyes denticulate, the occipital corners with a small, broad but low triangular tooth. Margins of frontal carinae arcuate, not crenulate nor denticulate; preocular tooth small and very broad basally. Margins of alitrunk not denticulate except for a single very small prominence upon the outer margin of each propodeal spine, on its apical half. Mesonotum separated from propodeum by a narrow but distinct notch or constriction. Propodeal spines long, tapering and acute apically. Petiole in profile with the steeply back-sloping anterior face meeting the sloping dorso-posterior face in an acute angle which is visible as a transverse ridge in dorsal view. Sides of first gastral tergite not marginate.

Sculpturation of a fine dense reticulate-puncturation everywhere which overlies any rugulation which may be present. Head finely reticulate-rugose, the cross-meshes tending to fade out in front of the level of the anterior margins of the eyes so that only the longitudinal component remains. Dorsum of pronotum reticulate-rugose but the remainder of the dorsal alitrunk with only fine, low, regular and more or less parallel longitudinal rugae. Upper part of propodeal declivity between the spines with one or two weak, transverse rugae, the remainder reticulate-punctate only. First gastral tergite with a very close and fine reticulate-puncturation and numerous short, irregular longitudinal rugulae.

Dorsal surfaces of head and alitrunk without erect hairs but the margins of the former with some minute hairs projecting laterally. Margins of alitrunk also with a few minute, projecting hairs. Dorsal surfaces of legs and gaster with scattered small hairs, best seen on the apical third of the latter.

Paratypes. TL 4.4 – 4.8, HL 1.04 – 1.16, HW 1.26 – 1.36, CI 117 - 121, EL 0.40 – 0.42, OI 30 - 32, IOD 1.02 – 1.10, SL 0.56 – 0.60, SI 44 - 45, PW 1.00 – 1.10, AL 1.20 – 1.38, MTL 0.60 – 0.68 (10 measured).

As holotype but some show the development of two or three low, blunt denticles upon the pronotal margin. In one of the smaller specimens erect hairs are completely absent from the first gastral tergite and the transverse rugae of the upper portion of the propodeal declivity may be very faint or even absent.

Male

Paratypes. TL 4.6 – 4.8, HL 0.96 – 1.00, HW 1.14 – 1.16, CI 116 - 119, EL 0.38 – 0.40, OI 33 - 35, IOD 0.94 – 0.98, SL ca 0.54, SI 46 - 47, PW 0.96 – 0.98, AL 1.52 – 1.60, MTL ca 0.70 (2 measured).

Occipital crest absent, sides of head behind eyes denticulate. Occipital corners with a well developed, broadly triangular tooth. Frontal groove indistinct, not reaching the median ocellus. Margins of pronotum and propodeum irregular but not denticulate, the propodeal spines very short and broad, blunt apically. Notauli completely absent or with a very weak impression marking the position of the anterior arms. First gastral tergite not marginate laterally. Head finely reticulate-rugose, the interspaces reticulate-punctate, and with the cross-meshes tending to disappear in front of the level of the eyes so that only the longitudinal component remains. Dorsal surfaces of pronotum and propodeum and the scutellum reticulate-rugose and punctate, the scutum more definitely longitudinally rugose but with some feeble cross-meshes. Gaster and the apical portions of the parameres finely and densely reticulate-punctate. Distribution of hairs as in worker.

Paratype Specimen Labels

Type Material

Holotype worker, PHILIPPINES: Negros Island, Dumaguete, 30.iv.1924 J., W. Chapman) (Museum of Comparative Zoology).

Paratypes. 14 workers, same data as holotype (MCZC, The Natural History Museum, National Museum of Natural History), 2 males, same data as holotype but without date of collection and stating '500 ft' (MCZ). 1 worker, same locality and collector as holotype but dated 28.iv.32 (MCZ). 1 worker and 1 male, same data as holotype but undated and bearing the number '405' (BMNH). 1 worker, PHILIPPINES: Luzon Island, Lamao, no further data (MCZ).

References