Monomorium santschii

The type was an inquiline female found with Monomorium salomonis in Tunisia. All samples known to the present have been found at the entrances to nests or within nests of salomonis-group members. According to Forel (1906) and Santschi (1913b) females of santschii approach the host nest and wait for a while at the entrance. They are soon accepted by the host workers and gain entry to the nest. Shortly thereafter the host workers kill their own reproductive female and adopt the inquiline, which goes on to lay numerous eggs. These produce only females and males; the worker caste has been lost. (Bolton 1987)

Identification
Morphologically only very slightly modified from other members of the Monomorium  salomonis-group. The females are very obviously specialized members of the salomonis-group in which the eighth funicular segment is enlarged to form a 4-segmented club and the occipital margin of the head has become strongly concave. The same modification of the head occurs weakly in the males, but their funiculi are normal for the salomonis-group. In both sexes the mesoscutum is flattened and bulges forward anteriorly so that it overhangs the pronotum, and in females the petiole and postpetiole nodes are anteroposteriorly compressed. These last two characters occur, though not as strongly developed, elsewhere in the salomonis-group. The female of Monomorium afrum shows modifications in structure that are surprisingly like those of santschii. Unlike santschii, however, afrum retains a worker caste. I suspect that the female of afrum may be a temporary social parasite.

Distribution based on Regional Taxon Lists
Palaearctic Region: Tunisia.

Nomenclature

 *  santschii. Wheeleria santschii Forel, 1905b: 171 (q.) TUNISIA.
 * Forel, 1906a: 52 (m.).
 * Combination in Wheeleriella: Emery, 1908f: 556; Emery, 1922e: 187.
 * Combination in Monomorium: Ettershank, 1966: 92.
 * Status as species: Forel, 1906a: 51; Emery, 1922e: 187; Bolton, 1987: 291; Bolton, 1995b: 266; Cagniant, 2006a: 196; Borowiec, L. 2014: 125.
 * Senior synonym of adulatrix: Bolton, 1987: 291.
 * Senior synonym of insidiosa: Bolton, 1987: 291.
 * Senior synonym of rufescens: Bolton, 1987: 291.
 * Senior synonym of Santschia intrudens: not previously recorded.
 * adulatrix. Wheeleriella adulatrix Santschi, 1913f: 229 (q.) TUNISIA.
 * Combination in Monomorium: Ettershank, 1966: 87.
 * Status as species: Emery, 1922e: 187.
 * Subspecies of santschii: Santschi, 1926e: 234.
 * Junior synonym of santschii: Bolton, 1987: 291.
 * insidiosa. Wheeleriella santschii st. insidiosa Santschi, 1926e: 233 (q.m.) TUNISIA.
 * Combination in Monomorium: Ettershank, 1966: 89.
 * Junior synonym of santschii: Bolton, 1987: 291.
 * intrudens. Santschia intrudens Forel, 1906a: 65 (in text).
 * Unnecessary replacement species-group name for Wheeleria santschii Forel, 1905b: 171.
 * Junior synonym of santschii.
 * rufescens. Wheeleriella santschii var. rufescens Santschi, 1926e: 233 (q.m.) TUNISIA.
 * Combination in Monomorium: Ettershank, 1966: 92.
 * Junior synonym of santschii: Bolton, 1987: 291.

Type Material
Bolton (1987) - Holotype female (dealate), Tunisia: Kairouan, 1 9. viii. 1903 (F. Santschi) (MHN) [examined].