Cardiocondyla weserka

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Cardiocondyla weserka
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Crematogastrini
Genus: Cardiocondyla
Species: C. weserka
Binomial name
Cardiocondyla weserka
Bolton, 1982

Cardiocondyla weserka casent0901748 p 1 high.jpg

Cardiocondyla weserka casent0901748 d 1 high.jpg

Specimen Labels

Nothing is known about the biology of Cardiocondyla weserka.

Identification

Bolton (1982) - Among the species of the region in which the metanotal groove is impressed, weserka is immediately distinguished by the shape of the propodeal dorsum. In general the propodeal dorsum is convex behind the groove and then enters a long slope down to the tubercles, spines or teeth, but in weserka the dorsum is almost flat and does not conform to this usual shape.

Seifert (2003) - A member of the Cardiocondyla emeryi group. Cardiocondyla weserka is most similar to Cardiocondyla neferka in surface structures, shape of head and waist segments, and morphometry. The only significant difference is the shape of the mesosoma. The dorsal propodeal profile is much less convex in C. weserka, which gives the whole dorsal mesosoma profile a more linear appearance, although the difference is less expressed than suggested by the figures in Bolton (1982). Furthermore, the pronotum of the C. weserka type does not show the conspicuous anterolateral pronotal corners seen in C. neferka. I have doubts whether these suggested differences between both taxa can be confirmed after the study of more material, nevertheless it is better to maintain the present status until further information is available.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Afrotropical Region: Cameroun (type locality).

Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Biology

Little is known about Cardiocondyla weserka. Until further studies reveal more about this species we can infer that its natural history and biology is likely similar to other members of the genus. Seifert revised the holarctic species of Cardiocondyla in 2003 and the following synopsis is based on his excellent treatment of the genus. References to other publications and more details about what is reported here can be found in Seifert (2003).

Many Cardiocondyla species inhabit areas that experience frequent disturbance and/or are quite open. These may be human altered areas, where a number of Cardiocondyla tramp species thrive, but also natural areas such as semi deserts and steppes, immature soils at rivers, lakes, and sea shores and to a lesser extent forest margins or burned-down woodland patches. In contrast to this open-land group, the natural habitat affinities of many tropical species are primary rain forests.

Nests are typically in soil and sometimes under stones. Two species are known to nest in vegetation but this is unusual for the genus. The single nest entrances is small (1-1.5 mm) and inconspicuous. In the desert nests can be relatively deep (> 1m) and have many chambers but in areas where conditions are less extreme there is generally a single chamber (15-20 mm diameter and 3-4 mm height) that is not far below the ground surface (2-15 cm).

Cardiocondyla tramp species (Cardiocondyla wroughtonii, Cardiocondyla obscurior, Cardiocondyla mauritanica, Cardiocondyla emeryi and Cardiocondyla minutior) are known to be polygynous, as are some less widespread species, while other species are known to be monogynous.

Cardiocondyla ants are omnivorous. Zoophagy (zoo necrophagy and killing of small weakly sclerotised arthropods), granivory, and nectarivory have also been noted. Tandem running has been observed as a method of recruitment to food sources in a few species.

Intranidal mating appears to be the norm for most species in the genus. Mating strategies are species dependent and may take various forms. Winged males may mate within their nest or fly to and enter other colonies to mate. Queen mate intranidally and fly from their nest to begin a new colony, become integrated into their natal colony, or may walk away from their nest and establish a new colony nearby.

Cardiocondyla are unusual in having peculiar male forms. Male polymorphism is found in some species with typical males and an ergatoid form. These latter males are wingless and worker like in appearance. Ergatoid males fight with other males within their natal nest. By killing potential rival males, a dominant male can monopolize matings with the virgin queens in their colony. Morphological modifications that enhance the fighting abilities of ergatoid males have been documented, e.g., modified mandibles well suited to fighting and increased mesosomal size for better protection against attacks from rivals. Another unusual characteristic of ergatoid males is the continuation of spermatogenesis throughout their adult life. Males of most aculeate hymenoptera stop producing sperm once they are fully mature.

Some species are known to produce different queen morphs. This presumably facilitates there being a longer range dispersal queen form and a shorter or non-dispersing form. Gyne polymorphism appears to be an adaptation for species inhabiting continental desert or semi-desert habitats. The cosmopolitan tramp species, on the other hand, do not exhibit this gyne polymorphism.

Castes

Only known from the worker caste.

Nomenclature

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

  • weserka. Cardiocondyla weserka Bolton, 1982: 317, fig. 6 (w.) CAMEROUN. See also: Seifert, 2003a: 280.

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 1.9, HL 0.46, HW 0.35, CI 76, SL 0.32, SI 91, PW 0.25, AL 0.48.

Antennal scapes moderately long but when laid back on the head failing to reach the occipital corners in full-face view. Maximum diameter of eye 0.12, about 0.34 x HW and with 9-10 ommatidia in the longest row. Pronotum in dorsal view with the corners narrowly rounded but not prominent. With the alitrunk in profile the promesonotum with its dorsum almost flat, rounding broadly into its anterior declivity but running into the metanotal groove almost in a straight line, with only the feeblest of curves. Metanotal groove narrowly but quite distinctly impressed. Behind the metanotal groove the propodeal dorsum more or less flat and on a slightly higher level than the posterior part of the promesonotum; the propodeal convexity behind the metanotal groove followed by a long slope down to the spines, which is characteristic of most species of the region, is absent here. Propodeal spines elongate and narrow, much longer than their basal width in profile; in dorsal view the spines somewhat incurved, each spine easily as long as the distance separating their bases. Shape of pedicel segments in profile as in Fig. 6. In dorsal view the petiole node conspicuously longer than broad, its dorsal surface narrow. Postpetiole much broader than long, its anterior face slightly concave, its sides convex. Dorsum of head blanketed by a fine dense granular sculpture or shagreening. Dorsal promesonotum more lightly shagreened than head, the sculpture here being extremely fine and very dense indeed. Propodeal dorsum with same sculpture as promesonotum but somewhat weaker and appearing shiny in places. Petiole and postpetiole very finely and superficially shagreened. Hairs absent except on mouthparts but a fine appressed pubescence is present, most easily visible on the first gastral tergite. Alitrunk medium brown, the appendages slightly lighter. Head dorsally and gaster blackish brown to black. Pedicel segments intermediate in shade between alitrunk and gaster.

Seifert (2003) - holotype: CS 404, CL/CW 1.231, SL/CS 0.790, PoOc/CL 0.440, EYE 0.247, dFOV 17, FRS/CS 0.229, SPBA/CS 0.296, SP/CS 0.212, PEW/CS 0.265, PPW/CS 0.455, PEH/CS 0.357, PPH/CS 0.289, PEW/PPW 0.572, PEH/PE 1.346, sqrtPDG 4.07, PLG/CS 7.62 %, MGr/CS 1.79 %.

Small size. Head much elongated, CL/CW 1.231. Scape rather short, SL/CS 0.790. Postocular index large, PoOc/CL 0.440. Eyes medium-sized, EYE 0.247, without clearly visible microsetae. Frons narrow, FRS/CS 0.229, frontal carinae immediately behind FRS level slightly converging and then diverging. Occipital margin more or less straight. Whole head and mesosoma without longitudinal sculpture, except for small patches with weak carinulae mentioned below. Anterior clypeal margin with median concavity. Vertex with deeply impressed, flat-bottomed foveolae of 16 - 18 mm diameter in densely-packed honey-comb arrangement; foveolae showing an inner corona (tubercle) of 8 - 10 mm diameter; median vertex posterior of frontal triangle with 2 - 3 very short longitudinal carinulae. Frontal laminae and clypeus foveolate. Pronotal shoulders rather developed, but rounded, not angulate. Dorsal mesosoma profile from pronotum caudad to propodeum at spiracular level rather linear, convex curvatures only indicated, metanotal groove shallow. Dorsal area of promesonotum irregularly reticulate, width of meshes 5 - 7 mm, scattered foveolae present. Dorsal area of propodeum irregularly reticulate-corrugated-foveolate; whole lateral area of mesosoma strongly microreticulate. Propodeal spiracle very small, inner diameter only 5 mm. Spines long, strong, and incurved; in lateral view deviating from longitudinal mesosomal axis by 20°. Petiole except for the more smooth and finely microreticulate dorsum with well-pronounced and dense microreticulum; node distinctly longer than wide, with narrow dorsal plane; node in lateral view massive, petiolar peduncle moderately long. Postpetiole in dorsal view wider than long, with angulate-convex sides and concave anterior margin, rather smooth, finely microreticulate; postpetiolar sternite rather flat, with well-pronounced, rounded anterolateral corners. Head, mesosoma, waist, and gaster dark brown; lateral pronotum and appendages lighter.

Type Material

Holotype worker, Cameroun: Nkoemvon, 1980, no. M35 (D. Jackson) (The Natural History Museum).

References