Probolomyrmex filiformis Mayr

Taylor, R. W., 1965, A monographic revision of the rare tropicopolitan ant genus Probolomyrmex Mayr (Hymenoptera: Formicidae)., Transactions of the Royal Entomological Society of London 117, pp. 345-365 : 353

Probolomyrmex filiformis Mayr (figs. 8 - 10)

Probolomyrmex filiformis Mayr , 1901, Ann. naturh. Hofmus. Wien 16: 3, [[ worker ]] Type locality: Port Elizabeth, South Africa.

Probolomyrmex filiformis : Arnold, 1915, Ann. S. Afr. Mus. 14: 34, [[ worker ]]. Redescription (of syntype?).

This is the type species of its genus, by monotypy. I have examined two syntype workers from the Mayr collection (Naturhistorisches Museum, Vienna); one is undamaged but the other lacks the head and gaster. These individuals are here selected as lectotype and paralectotype respectively and have been labelled accordingly.

Additional description. The aforementioned specimens have the following dimensions (lectotype cited first); HL, 0.76 mm.; HW, 0.48 mm.; SL, 0.54 mm.; CI, 63; SI, 113; WL, 1.03, 1 - 01 mm.; PW, 0.35,0.37 mm.; dorsal petiole width, 0.23, 0.24 mm.; petiolar node index, 66, 65; petiole height, 0.39, 0.39 mm.; petiolar node length, 0.34, 0.35 mm.; lateral petiolar index, 87, 90. The descriptions of Mayr and Arnold adequately cover the general features of P. filiformis , which are illustrated in figures 8 - 10. As the subpetiolar process of the lectotype is damaged, that of the paralectotype is shown in figure 9; the posteroventral tooth of the process was present also in the specimen described by Arnold. The carina enclosing the posterior face of the node has its edge very feebly emarginate at the dorsal mid-line. When viewed from above, the declivitous face of the propodeum is moderately concave, the depth of the concavity being about one-eighth the distance between the dorsalmost corners of the posterolateral propodeal lamellae.

Details of sculpturation, required for comparison with the related P. guineensis , as follows: the 2 general sculptural elements, fine shagreening and associated coarse punctures, are present, but the puncturation is relatively weak. Entire surface of body, including mandibles, antennae and legs, very finely shagreened and moderately shining. Front and sides of head, entire pronotum and dorsum of mesosoma with very indistinct vestigial traces of overlying puncturation. Individual punctures increasingly distinct towards lower parts of sides of mesosoma; best developed, though still somewhat indistinct, on the mes- and metepisterna. Puncturation of sides of petiole similarly developed, that of first two gastric segments slightly less so.

Pilosity normal for the genus. Whitish, extremely fine, adpressed pubescence moderately well developed over entire body, most abundant on gaster and least so on dorsum of mesosoma and underside of head. The visible apical segments of maxillary and labial palpi, and the preapical maxillary segment, proportioned as in P. angusticeps .

Distribution. - Known only from the type locality, South Africa: Port Elizabeth (Brauns).