Melissotarsus beccarii

Identification
The key character given to separate beccarii and Melissotarsus emeryi workers is quite weak. In most individuals there is a reasonable visible difference between the two, with the anterior pronotal margin rounding bluntly into the declivity in beccarii, and with the anterior pronotal margin separated from the declivity by an angle or edge in emeryi. Having said that, however, it should be pointed out that the difference is not so well marked in some individuals, which in consequence are difficult to place. Both species have a pale yellow feebly sclerotized male. Females of both species have the postpetiole in dorsal view conspicuously broader than long but it seems that two species are present as in some the mesoscutum is longer than broad (beccarii) but in others broader than long (emeryi). It should be admitted that very few worker-associated females are known and further collections may annul this apparent difference. To sum up, for the present I recognise these two as separate on the strength of the differently shaped mesoscutum in females and the form of the anterior pronotal margin in workers, but harbour a suspicion that only a single real species may in fact be represented here. M. beccarii differs from Melissotarsus weissi fairly consistently in all castes. The workers of weissi are darker in colour than those of beccarii and have both the anterior pronotal margin and the sides of the alitrunk relatively strongly marginate. The male is dark brown to black and strongly sclerotized, and in the female the postpetiole is relatively narrow in dorsal view with an arched-convex anterior margin which is quite different in shape from the strongly transverse form seen in beccarii. (Bolton 1982)

Distribution based on Regional Taxon Lists
Afrotropical Region: Eritrea, Ivory Coast, South Africa, Tanzania. Palaearctic Region: Ethiopia.

Nomenclature

 *  beccarii. Melissotarsus beccarii Emery, 1877b: 379, fig. (w.) ETHIOPIA. Forel, 1914d: 243 (q.m.). See also: Arnold, 1916: 189; Bolton, 1982: 336.

Worker
Bolton (1982) - TL 2.3-3.3, HL 0.56-0.82, HW 0.56-0.80, CI 97-105, SL 0.24-0.34, SI 39-47, PW 0.34-0.55, AL 0.58-0.80 (15 measured).

With the head in full-face view the occipital margin concave, sometimes deeply so medially, and with the sides convex and weakly to distinctly convergent in front of the eyes. Mandibles with a long finger-like apical tooth, worn down to nothing in some specimens; the mandibles unsculptured. Eyes much longer than broad, strip-like in many, the maximum diameter 0.12-0.16, about 0.18-0.22 x HW. Median portion of clypeus raised above the level of the lateral portions, not extending back between the frontal lobes; the latter contiguous and separated only by an impressed line. Scapes very short, SI < 50. Alitrunk in dorsal view with anterior pronotal margin rounding into the declivity, the two surfaces not separated by a sharp edge or angle. Dorsum of alitrunk roughly rectangular longitudinally, somewhat narrower behind than in front but not strongly so, and with the dorsum rounding into the sides. In profile the promesonotal dorsum and anterior propodeum are more or less fiat but the posterior part of the propodeum rounds very broadly and evenly into the declivity, without trace of armament. Fore coxae small, about half the size of the strongly swollen middle and hind coxae. Peduncle of petiole short and grading into the relatively high narrow node, the node with a short posterior free face, broadly attached to the postpetiole. In dorsal view the petiole node much broader than long. Postpetiole in dorsal view much broader than long, slightly broader than the petiole and very broadly attached to the first gastral tergite without a posterior constriction. Gaster only feebly sclerotized, crumpled in most mounted specimens. Dorsum of head with a silky superficial ground-sculpture upon which scattered small pits are usually superimposed. The ground-sculpture may cover the whole head but frequently it fades out occipitally. Median portion of clypeus more densely and strongly sculptured than dorsum of head capsule. Dorsal alitrunk finely longitudinally costulate throughout, the costulae fading out where the propodeal dorsum rounds into the declivity. Dorsal surfaces of head, scapes, pronotum, mesonotum, pedicel segments and gastral tergites with scattered sparse long fine hairs. Propodeal dorsum usually with one or two shorter hairs but these are frequently missing. Dorsal (outer) surfaces of tibiae with sparse long hairs similar to those on alitrunk. Head and alitrunk dull yellowish brown to dark yellow, the gaster lighter, usually pale dull yellow.