Asphinctopone silvestrii Santschi

Bolton, Barry & Fisher, Brian L., 2008, The Afrotropical ponerine ant genus Asphinctopone Santschi (Hymenoptera: Formicidae), Zootaxa 1827, pp. 53-61 : 57-59

Asphinctopone silvestrii Santschi

( Figs 1 a,b; 2a,c)

Asphinctopone silvestrii Santschi, 1914: 318 , fig. 6. Holotype worker, NIGERIA: Olokemeji, xii. 1912 (F. Silvestri) (not in DEUN or NHMB, presumed lost; see note).

Asphinctopone lucidus Weber, 1949: 7 , figs. 5–7. Holotype worker, CENTRAL AFRICAN REPUBLIC (= “Fr. Equat. Africa” on data label): Ubangi-Shari, Bas Mbomu, 5 mi. W. of Bangassou, 12.iii.1948, #2210 (N.A. Weber) (AMNH) [examined]. Syn. n.

Lepidopone lamottei Bernard, 1953: 208 , fig. 4. Holotype worker, GUINEA: 22. Nyon For. (= Nion, Mt. Nimba), 10.1.8/ 2 (Lamotte) (MNHN) [examined]. Syn. n. [Combination in Asphinctopone by Brown, 1953: 3.]

Note. Conversations between Bruno Spinosa (DEUN) and Fabrizio Rigato (MSNM), as reported to Barry Bolton, have established that the holotype of A. silvestrii cannot be found in the Silvestri collection in Naples. Daniel Burckhardt (NHMB) informs us that the silvestrii holotype has never been in the Santschi collection.

Worker. TL 3.3 – 3.6, HL 0.78 – 0.83, HW 0.62 – 0.68, CI 78 – 83, SL 0.53 – 0.63, SI 85 – 93, PW 0.44 – 0.49, WL 0.96 – 1.06 (20 measured).

Mandible smooth and shining, unsculptured except for a few pits from which hairs arise. Eye small, maximum diameter 0.04 – 0.06 (OI 6 – 9), of only 5 – 8 poorly defined ommatidia. No distinct carina present between eye and base of mandible but a fine, weak cuticular crest present laterally that extends from the base of the mandible to above the eye, and terminates just behind the level of the eye. In full-face view posterior margin of head very shallowly convex. In the same view the scape, when laid straight back from its insertion, just fails to reach, to fractionally exceeds, the posterior margin. Dorsal surface of frontal lobes more strongly sculptured than remainder of head. Dorsum of head finely minutely punctulate; sides behind and below eyes with widely scattered, slightly larger punctures, the spaces between them smooth and shining. Promesonotal suture with short cross-ribs on the anterior margin of the mesonotal section. In profile the promesonotal suture and metanotal groove are both narrow and deeply impressed, so that the relatively short mesonotum forms a distinct, isolated convexity between them. Base of metanotal groove with short cross-ribs. Sulcus between mesonotum and mesopleuron present, the latter also with a transverse sulcus that divides it into anepisternum and katepisternum. Propodeal outline in profile slightly variable in shape: length and slope of dorsum shows variation, as does the degree of convexity of the dorsum and posterior angle, and the convexity of the posterior face, which varies from straight to very weakly convex. Propodeum unarmed and the small propodeal spiracle is low down on the side. Dorsum of pronotum and mesonotum sparsely sculptured with scattered small punctures, the density of the punctures weakly variable between individuals; punctures on propodeal dorsum more coarse. Side of propodeum with scattered punctures, the spaces between them generally smooth but sometimes with faint traces of interstitial sculpture; propodeal declivity unsculptured, weakly marginate laterally. Legs relatively short, maximum length of hind femur 0.60 – 0.67. Petiole surmounted by an unsculptured high, narrow scale that is convex dorsally (petiole maximum height 0.52 – 0.58; maximum thickness of scale in profile 0.14 – 0.18); scale in dorsal view broad (maximum width 0.36 – 0.39). Petiole with a short posterior peduncle that is equipped dorsally with three strong transverse carinae; rarely there is a trace of a fourth carina posteriorly. Subpetiolar process complex, as discussed above. First and second gastral tergites with small punctures, those on the second tergite usually somewhat more dense than on the first; spaces between punctures smooth and shining. Setae sparsely present on clypeus, very dense on pygidium and hypopygium, but otherwise all dorsal surfaces of head, mesosoma, petiole and gaster lack setae. Ventral surface of head with 1 – 2 short setae present, and a few on gastral sternites 1 – 3. Scapes, femora and tibiae have fine appressed pubescence but completely lack standing setae. Dorsal surfaces of head and mesosoma with sparse appressed pubescence, especially scanty on the dorsal propodeum where it is almost absent. Colour of individuals varies from reddish yellow to reddish brown.

Queen. TL 3.8, HL 0.79, HW 0.64, CI 81, SL 0.56, SI 88, PW 0.52, WL 1.08.

Slightly larger but otherwise very similar to the worker, with cephalic measurements falling within the same range. The extra size is accounted for by the mesosoma, which has a full set of flight sclerites, and a slightly larger gaster. Transverse sulcus on mesopleuron is more strongly developed than in worker. Head with three ocelli present; eye distinctly larger than in worker, its maximum diameter 0.16 (OI 25). Known from only a single dealate specimen (BMNH).

Following the initiation of the genus and its type-species silvestrii by Santschi (1914), two other specimens collected by subsequent authors were also described as new species, lucidus and lamottei . Each of these is based on single specimens, as was silvestrii . The two later authors apparently relied only on published descriptions and never examined type-specimens. Although none of the descriptions was very detailed, they indicated that the three nominal taxa were extremely closely related and probably synonymous. The loss of the earliest of the three holotypes grouped here makes direct comparison impossible now, but an overview of all the material that is available, and its comparison with the two surviving holotypes and the description of the missing holotype, confirms that only a single species is represented.

Weber’s description and figures of A. lucidus indicate nothing to separate it from the mass of material examined, except for his comment that the scapes are longer than in silvestrii . In the material examined, the scapes, when laid straight back from their insertions in full-face view, range in length from just failing to reach the posterior margin of the head to just exceeding the margin, with intermediate lengths present. Small changes in the orientation of the head make the scapes appear to extend to different distances. Weber’s fig. 5 shows the scapes crossing the lateral margin of the head just in front of the posterior corners. This also occurs in other material when the scapes are oriented similarly. Therefore Weber’s assertion that the scapes of lucidus are longer is incorrect; he was merely comparing his specimen with a drawing that did not have the same orientation. Measurement of the holotype of lucidus confirmed this as its SI of 93, although at the upper end of the measured range, is frequently duplicated throughout the species, and every SI from 85 to 93 has been recorded.

A Nigerian specimen from Gambari, not far from the silvestrii type-locality of Olokemeji, matches Santschi’s description in all respects except colour; it is a somewhat darker reddish brown. This specimen, in turn, is indistinguishable from the holotype of lamottei and from the other material examined.

All examples of this species were retrieved from samples of leaf litter or topsoil, or in the rotting trunks of fallen trees, small pieces of dead wood, a rotting banana stem on the forest floor, and once from a termitary.

Material examined. Guinea: Mt Nimba, Nion (Lamotte). Ivory Coast: Forêt de Teke, Anyama (T. Diomande); Ndouci, Nzi Noua (W.L. Brown); Lamto, Toumodi (J. Levieux); Lamto (K. Yeo); Adiopodoumé, nr Abidjan (I. Löbl). Ghana: Bunso (R. Belshaw); Eastern Bunso (R. Belshaw); Ofinso (R. Belshaw). Nigeria: Gambari (B. Bolton). Cameroun: Ebodjie (A. Dejean); Mbalmayo (N. Stork); Nkoemvon (D. Jackson); Prov. Sud-Ouest, Korup N.P., NW Mundemba (B.L. Fisher); Prov. Sud, N’kolo, Bondé For., SSE Elogbatindi (B.L. Fisher); Res. de Faune de Campo, ESE Ébodjé (B.L. Fisher); Res. Campo, Massif des Mamelles (B.L. Fisher). Gabon: Prov. Woleu-Ntem, ESE Minvoul (B.L. Fisher); Prov. Estuaire, F.C. Mondah, NNW Libreville (B.L. Fisher). Central African Republic: Ubangi-Shari, Bas Mbomu, Bangassou (N.A. Weber); P.N. Dzanga-Ndoki, Lidjombo (B.L. Fisher).

Figures

FIGURE 1. Asphinctopone spp. full face and lateral view. A – B, silvestrii worker, CASENT 0178222; C – D, differens holotype worker CASENT 0417143.