Cataglyphis bicolor

This is one of two species of Cataglyphis (also Cataglyphis fortis) that have had their foraging behavior, and in particular their navigation abilities, intensively studied. The results of this body of work provide a remarkable accounting of how ants, and animals in general, can track and monitor their movement in ways that allow for sophisticated decision making. These studies have examined these two ants' sensory and nervous systems, their directional abilities, use of path integration, and view-based landmark guidance, and how all of this is brought together to determine where an individual decides to move. These ants are now a model organism for the study of animal navigation. Rüdiger Wehner has been at the center of much of this Cataglyphis research. Wehner and his colleagues have been conducting seasonal fieldwork studying C. bicolor and C. fortis in the area of Mahrès, Tunisia for 50 years (Wehner 2019). The book Desert Navigator:The Journey of an Ant (Wehner 2020) provides a fascinating summary of how this work was accomplished and its many important findings.

Distribution based on Regional Taxon Lists
Afrotropical Region: Eritrea. Palaearctic Region: Algeria, Canary Islands, Turkey.

Morphology
Penmetcha et al. (2019) - Desert ants of the genus Cataglyphis and Melophorus possess all three ocelli and are the only ants in which the function of the ocelli has been studied. Size of the ocellar lens and width of the ocellar rhabdoms in cross-section are typically larger in nocturnal insects (Warrant et al. 2006; Somanathan et al. 2009; Narendra et al. 2011; Narendra and Ribi 2017). This increases their optical sensitivity and allows individuals with larger ocelli to forage in slightly dim light conditions (Wellington 1974). The desert ants that we studied being strictly day-active had small lenses and narrow rhabdoms (in Cataglyphis spp) compared to the night-active Myrmecia.

Here we characterised the anatomical organisation of the ocelli in three species of desert ants (Cataglyphis bicolor, Cataglyphis fortis, and Melophorus bagoti). Cataglyphis bicolor, an ant that forages in both saltpans and around urban regions, had a fused rhabdom. Each rhabdom was composed of two retinula cells that contributed microvilli perpendicular to the long axis of the rhabdom. This organisation of the ocellar retina is likely to make them polarisation sensitive. Similarly organized rhabdoms are known from winged male ants (Narendra and Ribi 2017), bees, and wasps (Zeil et al. 2014; Ribi and Zeil 2018). Our anatomical data lend support to the behavioural (Fent and Wehner 1985; Fent 1986) and physiological evidence (Mote and Wehner 1980) of polarisation sensitivity in the ocelli of C. bicolor.

Nomenclature

 *  bicolor. Formica bicolor Fabricius, 1793: 351 (m.) NORTH AFRICA. Wheeler, G.C. & Wheeler, J. 1980: 538 (l.). Combination in Cataglyphis: Roger, 1863b: 12; Mayr, 1863: 402; Emery, 1912f: 98; Emery, 1915g: 22; in Myrmecocystus: Emery & Forel, 1879: 449. Junior synonym of viatica: Smith, F. 1861a: 32; Nasonov, 1889: 14. Revived from synonymy: Emery & Forel, 1879: 449; Emery, 1906d: 58; Forel, 1907e: 15. Subspecies of viatica: Forel, 1907e: 15. Revived status as species: Karavaiev, 1912b: 590; Emery, 1925b: 264; Santschi, 1929b: 41. Senior synonym of fairmairei: Santschi, 1929b: 41; of megalocola: Mayr, 1855: 382; Santschi, 1929b: 41; of rotundinodis: Santschi, 1929b: 41. Biogeography of bicolor group: Wehner, R., Wehner, S. & Agosti, 1994: 163. Current subspecies: nominal plus adusta, basalis, congolensis, pubens, rufiventris, seticornis, sudanica.
 * fairmairei. Cataglyphis fairmairei Foerster, 1850b: 494 (m.) ALGERIA. Junior synonym of megalocola: Mayr, 1863: 402.
 * megalocola. Formica megalocola Foerster, 1850b: 490 (w.) ALGERIA. Emery, 1891b: 16 (q.m.). Combination in Cataglyphis: Roger, 1863b: 12; Mayr, 1863: 402; in Myrmecocystus: Emery & Forel, 1879: 449; Forel, 1890a: lxvii; in Cataglyphis: Emery, 1912f: 98; Emery, 1925b: 265. Subspecies of viatica: Emery & Forel, 1879: 449; Forel, 1890a: lxvii; Forel, 1892i: 306; of bicolor: Emery, 1906d: 58; Emery, 1908g: 217. Senior synonym of fairmairei: Mayr, 1863: 402. Junior synonym of bicolor: Mayr, 1855: 382; Santschi, 1929b: 41; Agosti, 1990b: 1486.
 * rotundinodis. Myrmecocystus albicans subsp. rotundinodis Karavaiev, 1912a: 16 (w.) ALGERIA. Combination in Cataglyphis: Emery, 1925b: 262. See also: Karavaiev, 1924: 305. Junior synonym of bicolor: Santschi, 1929b: 41.