Feroponera ferox, Bolton, Barry & Fisher, Brian L., 2008

Bolton, Barry & Fisher, Brian L., 2008, Afrotropical ants of the ponerine genera Centromyrmex Mayr, Promyopias Santschi gen. rev. and Feroponera gen. n., with a revised key to genera of African Ponerinae (Hymenoptera: Formicidae), Zootaxa 1929, pp. 1-37 : 26-28

Feroponera Bolton & Fisher gen. n.

Type-species: Feroponera ferox sp. n., by present designation.

DIAGNOSIS OF WORKER

A monotypic Afrotropical genus.

1 Mandible with a basal groove but no basal pit; cuticle of dorsum with a marked pale patch that is much lighter in colour, adjacent to teeth 4 + 5.

2 Mandible subtriangular, short and stout (MI 37–38), with 5 teeth: apical tooth the largest by far, curved and acute, strongly crossing over the opposing mandible at full closure; also at full closure a space is present between the masticatory margins posterior to tooth 3; preapical tooth reduced; third tooth triangular, the largest after the apical; fourth tooth triangular, smaller than third; fifth tooth smaller still; proximal of the fifth tooth the basal angle is abruptly but bluntly rounded.

3 Palp formula 2,3; apical labial palpomere globular.

4 Anterior clypeal margin on each side with a broadly triangular tooth that projects anteriorly over the basal margins of the closed mandibles.

5 Frontal lobes confluent medially; in full-face view their anterior margins overhang the anterior clypeal margin except medially, where a small toothlike clypeal prominence is visible.

6 Mid-dorsal groove of head does not extend posterior of the terminus of the frontal lobes.

7 Eyes absent.

8 Antenna with 12 segments, with a conspicuous 4-segmented club that is longer than SL.

9 Pronotum marginate anteriorly, more bluntly so laterally.

10 Metanotal groove absent.

11 Orifice of metapleural gland posterior, near the posteroventral corner of the mesosoma.

12 Metasternal process a pair of separated elongate triangular teeth; metasternal pit located between them.

13 Propodeum unarmed, bilaterally compressed in dorsal view so that the dorsum is much narrower than the mesonotum.

14 Propodeal spiracle elliptical, low on the side, almost touching the dorsal margin of the metapleural gland bulla.

15 Propodeal lobes extremely reduced, rounded.

16 Procoxa much larger than mesocoxa and metacoxa.

17 Mesotibia, mesobasitarsus and metabasitarsus with stout spiniform traction setae (none on metatibia).

18 Mesotibia with 2 spurs, both simple.

19 Metatibia with 2 spurs: the anterior simple, the posterior large and broadly pectinate.

20 Metatibial posterior surface with a slightly depressed broadly oval area of pale, very finely granular, cuticle that extends proximally from the base of the spur and appears to be glandular.

21 Petiole sessile, without an anterior peduncle; subpetiolar process deep but blunt.

22 Helcium arises just below mid-height of anterior face of first gastral segment.

23 Prora a pair of insignificant ridges that arise on each side of the helcium base and extend weakly around the anteroventral corner of the first gastral sternite; anterior face of sternite between the ridges very feebly concave.

24 Constriction of second gastral segment conspicuous, weakly cross-ribbed.

25 Stridulitrum absent.

Discussion of worker characters

Apomorphic characters, in italics above, include 1 (pale mandibular patch), 2 (dentition), 4, 8 (antennal club) and 20. In some respects Feroponera workers are superficially similar to Promyopias workers but, as well as the different apomorphic characters of the two, Feroponera also differs markedly in characters 3, 5, 6, 15, 18 (mesotibial spurs) and 23. Characters 1–25 together form an inclusive diagnosis that isolates Feroponera workers from all other genera in the tribe.

1 A mandibular pale patch is very obvious in all workers. This patch of translucent cuticle on the mandible dorsally covers a much paler internal structure. The colour may be the result of a cavity within the mandible that is lined with paler tissue, or it may be made entirely of lighter internal tissue. The structure may be glandular, but this cannot be determined by light microscopy. The structure appears unique to Feroponera , but it should be mentioned that Centromyrmex secutor has a flattened area with a distinctly crowded patch of minute punctures in approximately the same position.

2 The form of the mandible and its dentition is unique. When the mandibles are fully closed the section that overlaps the opposite mandible extends to tooth 3. The overall impression is that of a shorter, stouter, much less extreme version of the mandibles exhibited by Emeryopone .

3 PF was obtained by dissection of one of the paratypes; the strangely reduced count is almost certainly apomorphic.

4 A similar pair of large clypeal teeth can be seen in the unrelated Neotropical genus Dinoponera . In the Afrotropical region Streblognathus and Asphinctopone have angular or dentate lateral corners to an extensive median clypeal lobe, but these do not correspond to the situation in Feroponera where no such lobe is developed.

5 The three genera Centromyrmex , Promyopias and Feroponera form a sequence in which the median clypeus reduces in length and the frontal lobes become progressively closer to the anterior margin.

8 The 4-segmented club is conspicuously much longer than the preceding 7 funicular segments together, and is much longer than the scape.

17 The presence and distribution of spiniform setae is duplicated in Centromyrmex and Promyopias : see discussion of potential genus group, below.

20 The position and shape of this depressed and apparently glandular area corresponds to that seen in the workers of Diacamma and in at least 25 Old World species of Pachycondyla (sensu lato; the feature does not appear in any New World species that we are aware of), but it is by no means universal even in Old World species. We suspect that it is an independent development of this genus.

22 Position of the helcium is similar in Centromyrmex and Promyopias : see discussion of potential genus group, below.

23 Structure of the prora is basically the same as that seen in the Centromyrmex feae group.