Boloponera

This genus is currently known from a single worker collected from leaf litter in the Central African Republic near the border of Gabon, Cameroon, and Congo. The collection details (from leaf litter) in combination with morphological characteristics (e.g., lack of eyes) suggests that it is cryptobiotic. The identity of its prey is unknown but its linear mandibles are suggestive of prey specialization.

Identification
Schmidt and Shattuck (2014) - Boloponera can be most easily diagnosed by the following unique combination of characters: mandibles linear, frontal lobes hypertrophied, eyes absent, head without posteroventral lamellae, propodeum with posterior lamellae, metafemora with longitudinal groove, mesotibiae and meso-/metabasitarsi without stout traction setae, relatively high helcium, and tergite A4 not arched. It bears significant similarity to Loboponera, Plectroctena, and Feroponera, but the characters above serve to differentiate it from all of these genera. Boloponera differs from Loboponera in having linear mandibles, loss of eyes, no posteroventral lamellae on the head, and a tubular tergite A4. It differs from Plectroctena in lacking a dorsal longitudinal groove on the mandibles, lacking excavations in the clypeus at the mandibular articulations, and lacking eyes. Boloponera can be separated from Feroponera by its linear mandibles, metafemoral grooves, and absence of traction setae on the middle and hind legs.

Fisher (2006) - Boloponera is reminiscent of Plectroctena. Both taxa have: (1) linear mandibles, (2) frontal lobes that project over mandible, (3) propodeal lamellae, and (4) metafemur with a longitudinal, possibly glandular groove. However, there are striking differences. The mandible of Boloponera lacks the characteristic large semicircular excavation in the clypeal margin at the mandibular articulation. Both taxa have linear mandibles, but Boloponera lacks the longitudinal groove on the inner half of the dorsal surface of the mandible blade.

In addition, Boloponera lacks the unique shape of the ventral anterior articulatory surface of the petiole found in the Plectroctena group. The Plectroctena group is characterized by the presence of a V-shaped groove or a narrow median pore-like depression on the anteriormost part of the ventral surface of the petiole (Bolton and Brown 2002). In Boloponera, the shape is similar to other Ponerini outside the Plectroctena group.

Boloponera differs from the only known Centromyrmex with elongate mandibles C. silvestrii by having frontal lobes that extend anteriorly and project out over the mandibular basal margins. In addition, Boloponera lacks the strong spines on the middle tibia and middle and hind basitarsi that characterize Centromyrmex. Boloponera is also superficially similar to Myopias but differs in lacking a second tibial spur and a clypeus that projects between the frontal lobes and extends over the basal margin of the mandibles. Based on overall characters, Boloponera along with Dolioponera may well constitute the sister group of the Plectroctena genus group. Centromyrmex may also prove to be closely related to the Plectroctena genus group.

Nomenclature

 *  BOLOPONERA [Ponerinae: Ponerini]
 * Boloponera Fisher, 2006: 112. Type-species: Boloponera vicans, by original designation.

Worker
Worker. Ponerinae ant with the characters of the Ponerini tribe listed in Bolton (2003) and also with the following:

1. Median portion of clypeus not extended anteriorly as a lobe that projects out over the mandibular basal margins.

2. Frontal lobes extend anteriorly and project out over the mandibular basal margins.

3. Labrum not visible in full-face view with mandibles closed.

4. Mandible linear, without large semicircular excavation in clypeal margin at mandibular articulation.

5. Postventral curve of head in profile without projecting curved flange.

6. Propodeal dorsum without median longitudinal groove or impression.

7. Metafemur with longitudinal (glandular) groove present along entire length.

8. A4 tergite tubular, not strongly arched and down-curved.

9. Anteroventral process on the A3 sternite present, but greatly reduced.

10. Anteriormost part of ventral surface of petiole with broadly horseshoe-shaped strip of cuticle.

11. Antennae 12-segmented.

Hawkes (2018) - As in Fisher (2006), with the following additions and modifications:

1. Glandular structure present on metafemur, visible for approximately 2/3 of the length of the femur as a thinning of the cuticle, without any impression or groove. No such structure visible on mesofemur.

2. Anterior disc of petiole with a broadly C-shaped to horseshoe-shaped strip of thicker cuticle surrounding a roughly semicircular patch of thinner cuticle.

3. Anterior margin of clypeus with a strongly convergent pair of long setae that cross at approximately their mid length.

4. Posterior margin of clypeus projecting anterad of the anterior clypeal margin and overhanging the closed mandibles.

5. Mandible with an apical tooth plus three pre-apical teeth; the sub-apical tooth is close to the apical and is followed by a large diastema before the third tooth, which is located near the fourth (basal) tooth at the basal angle, near the mid-length of the mandible.

6. Metapleural gland orifice opening dorsally oriented, clearly visible in dorsal view but largely obscured in lateral view; posteriorly it is completely hidden by the upwardly extended ventral flap.

Description
Schmidt and Shattuck (2014):

Worker
Small (TL 3.3 mm) robust ponerine ants with the standard characters of Ponerini. Mandibles linear, with two small teeth and a basal groove. Frontal lobes hypertrophied and and projecting beyond the anterior clypeal margin. Antennae with two-segmented club. Eyes absent. Mesopleuron divided by a transverse groove, the anepisternum appearing fused to the mesonotum and metapleuron. Metanotal groove absent. Propodeum broad dorsally, the posterolateral margins drawn out posteriorly into cuticular lamellae. Propodeal spiracles round. Metafemora with dorsal longitudinal groove. Metatibial spur formula (1p). Petiole nodiform, the subpetiolar process a posteriorly-directed tooth. Helcium projecting from near midheight on the anterior surface of A3. Strong constriction between pre- and postsclerites of A4 apparent. Head and body foveate and longitudinally striate, with abundant short pilosity and no pubescence. Color orange.