Myrmecocystus albicans , Emery 1891
Creators: name: Agosti, Donat
Publisher: name: Zenodo
Year: 1990
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Formicidae
Myrmecocystus
Myrmecocystus albicans

description: albicans group
Diagnosis
Workers and females: Catagylphis ants with the following diagnostic characters:
1. Petiole nodiform, with the anterior dorsal face plane; in lateral view the dorsal outline is angled (Fig. 8). During locomotion the gaster is bent backwards, forming almost a right or blunt angle between the ventral surface of the gaster and a line spanned between the anteriormost and posteriormost point of the alitrunk (Fig. 2).
2. MPI> 90; third segment of the maxillary palps compressed in cross-section (with the exception of cinnamomeus) with the fourth segment of the same length or shorter than the fifth and the sixth together.
3. Uniform black and shining to bright yellow and shining, sometimes bicoloured with the gaster darker than the remaining parts of the body.
4. Fringe of hairs on the margins of the propodeum.
5. Alitrunk length of large workers up to 3 -2 mm, rather uniform in size.
6. Females with a high scale-like petiole.
Males: Catagylphis ants with the following diagnostic characters:
1. Uniform black to bicoloured with a reddish alitrunk and a darker gaster.
2. Subgenital plate long (SPI> 125); the apex variable, from two distal, lateral processes and a median part which is variable but always present to a truncated apex which is in cross-section a simple plate with the lateral parts bent dorsally (Figs 25-27).
3. Squamula caudally always projecting over the stipes, sometimes forming a distinct process pointing ventrally (Figs 40-42).
4. Stipes without a median appendix, at most indicated by a minute bulge.
5. Volsella curved, distally convergent and pointed (Figs 60-62).
6. Sagitta elongated apically (Figs 75-77) or not, but then the anteromedian appendix and the anterior teeth very prominent (Fig. 75); the dorsocranial appendix wide and truncated (Figs 75-77); the ventral (serrated) surface toothless.
Distribution
The albicans species-group is distributed from Spain through North Africa and the Middle East to the northern territories of Pakistan, from Bulgaria to the Sudan and the southern Arabian peninsula. Ecologically, the albicans and the bicolor species-groups are similar but the former is to be found in hotter places (especially ants of the lividus complex) and higher up in the Karakorum. Analogous to diehlii in the bicolor species-group there is fortis in the albicans groups, which lives in Chotts of northern Africa.
Comments
Within the albicans species-group is a cline from uniform black to reddish and bright yellow body colour, which corresponds to some extent with a temperature gradient, the brightest yellow to be found in the hottest sand deserts.
Four species complexes are differentiated, of which only the males of the albicans and the fortis complex are known. The proposed grouping into a fortis and an albicans complex, based on male genitalia characters, is tentative because the Iberian albicans and some of the bicoloured Middle Eastern forms fall within the fortis complex rather than the albicans complex centred around the North African albicans (Tinaut and Plaza, 1989; Agosti, unpublished; see also albicans, note 1; Wehner, 1983 and Martinez, 1987).
The four arbitrary species-complexes, based on worker characters, are diagnosed by the following characters:
(i) albicans complex: workers with black to bright red or orange head and alitrunk, gaster in bicoloured species always distinctly darker, large workers up to AL = 3-2 mm, MPI> 90, second funicular segment much shorter than previous (FI> 150); if nearly uniform yellowish then SI <110 (> 110 in lividus) and Cl <96 (> 96). Distribution: over the whole range of the albicans species-group except the southernmmost parts in deserts and semidesert habitats.
(ii) cinnamomeus complex: workers brownish black, shining with MPI <90 and FI> 150. Distribution: from the Crimea through Central Asia to Baluchistan.
(iii) fortis complex: jet black workers, AL <3-6 mm, the second funiculus segment slightly longer than the previous (FI <130). Distribution: Chotts of North Africa.
(iv) lividus complex: uniform, bright yellow species, AL <3 mm, FI <150. Distribution: from Morocco to the Indus river including the Arabian peninsula, in semideserts to deserts.
Catalogue of the available names in Cataglyphis
description: Published as part of Agosti, Donat, 1990, Review and reclassification of Cataglyphis (Hymenoptera, Formicidae), pp. 1457-1505 in Journal of Natural History 24 on pages 1479-1480, DOI: 10.5281/zenodo.14982