Messor capitatus

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Messor capitatus
Preparation of Messor capitatus

Preparation of Messor capitatus

Systematics
Order : Hymenoptera (Hymenoptera)
Family : Ants (Formicidae)
Subfamily : Knot ants (Myrmicinae)
Tribe : Pheidolini
Genre : Messor
Type : Messor capitatus
Scientific name
Messor capitatus
( Latreille , 1798)

Messor capitatus is a harvest ant species found in the western Mediterranean and the Atlantic coast, including western North Africa.

features

As is typical for Messor species, the workers in Messor capitatus are very different from one another in size (polymorphic); animals between 5 and 12 millimeters in length can appear. The species differs from other Messor species in that it has short hairs on the entire body, especially the abdomen (shorter than in the species of the structor group), a second antennae that is less than twice as long as it is wide and a monochrome black body color. There is no particularly long group of bristles (psammophores) on the underside of the head.

The most similar species that occurs together with Messor capitatus is Messor barbarus , with which it is placed in a common species group. Earlier authors often viewed Messor capitatus only as a subspecies of Messor barbarus . The types are best distinguishable on large workers (majores). In the case of Messor capitatus , the propodeum is angular at the top, and in Messor barbarus it is rounded. In addition, the head of these workers in Messor barbarus is clearly reddish in color, while Messor capitatus is monochrome black.

Way of life

Messor capitatus creates monogynous earth nests. As is typical for species of the genus Messor , the species feeds on plant seeds in a highly specialized manner. She enters this into the building and builds up supplies. The search strategy differs from that of other Messor species, with which it often occurs together in the same habitat. Typically, the workers swarming out of the underground nest form stable roads (trunk trails) that are used for months to years and kept free of obstacles. These eventually branch out into less stable, smaller streets. The workers of Messor capitatus then search for about 90% individually, not like the representatives of most other species in groups. The roads also tend to be shorter and less stable. The streets of neighboring colonies do not cross, they will probably be marked chemically. This is how the food territory is divided up. After experiments with artificial seeds, the species does not select based on the size of the seeds. Workers from different colonies often steal each other's seeds when they meet (kleptobiosis).

Recent observations have shown that Messor capitatus and representatives of two other species ( Messor minor and Messor wasmanni or a closely related species) often occur in common, mixed-species nests in the area. The identity of the (difficult to determine) species was examined both morphologically and with genetic markers. It turned out that Messor minor and cf. Messor wasmanni , but not Messor capitatus, also often form mixed species (hybrids). Although a final explanation is still pending, the observation could be explained by brood robbery or socially parasitic nest building (in which a queen of one species penetrates the nest of another species and this, together with the existing workers, "takes over" by displacement of the queen).

As one of only four previously known species of ants, after the loss of the queen in a colony, Messor capitatus produces new female sex animals by workers. Since the workers are unfertilized, it is a form of parthenogenesis (thelytokia). Colonies kept in the laboratory without a queen could also produce males after a while. So you can parthenogenetically produce both sexes (mixed parthenogenesis, amphitocia or deuterotocia). In contrast to some other Hymenoptera species with this mode of reproduction (overall only very few are known), the parasitic bacterium Wolbachia plays no role in Messor capitatus .

Individual evidence

  1. ^ CA Collingwood (1976): A provisional list of Iberian Formicidae with a key to the worker caste. Eos 52: 65-95.
  2. ^ D. Agosti & CA Collingwood (1987): A provisional list of the Balkan ants (Hym., Formicidae) with a key to the worker caste. II: Key to the worker caste, including the European species without the Iberian. Communications from the Swiss Entomological Society 60: 261-293.
  3. ↑ H. Cagniant & X. Espadaler (1997): Le genre Messor au Maroc (Hymenoptera: Formicidae). Annales de la Société Entomologique de France (NS) 33 (4): 419-434.
  4. ↑ Figure
  5. ↑ NJR Plowes, RA Johnson, B. Hölldobler (2013): Foraging behavior in the ant genus Messor (Hymenoptera, Formicidae, Myrmicinae). Myrmecological News 18: 33-49.
  6. ↑ X. Arnan, J. Retana, A. Rodrigo, X. Cerda (2010): Foraging behavior of harvesting ants determines seed removal and dispersal. Insectes Sociaux 57: 421-430 doi : 10.1007 / s00040-010-0100-7
  7. ↑ Michael D. Breed, Chelsea Cook, Michelle O. Krasnec (2012): Cleptobiosis in Social Insects. Psyche Volume 2012, Article ID 484765, 7 pages doi : 10.1155 / 2012/484765
  8. ↑ Florian M. Steiner, Bernhard Seifert, Donato A. Grasso, Francesco Le Moli, Wolfgang Arthofer, Christian Stauffer, Ross H. Crozier, Birgit C. Schlick-Steiner (2011): Mixed colonies and hybridization of Messor harvester ant species (Hymenoptera : Formicidae). Organisms Diversity & Evolution Volume 11, Issue 2: 107-134. doi : 10.1007 / s13127-011-0045-3
  9. ↑ DA Grasso, T. Wenseleers, A. Mori, F. Le Moli, L. Billen (2000): Thelytokous worker reproduction and lack of Wolbachia infection in the harvesting ant Messor caitatus. Ethology, Ecology and Evolution 12: 309-314. PDF

Web links

Commons : Messor capitatus  - collection of images, videos and audio files