Asphinctopone differens

Asphinctopone differens is rarely collected. Nothing is known about its biology.

Identification
differens = With the propodeum in profile the dorsum with a pelt of erect, weakly curved pubescence. Side of propodeum entirely densely irregularly sculptured (Central African Republic)

Asphinctopone pilosa = 1) larger size, 2) stronger and much more extensive sculpturation and denser pubescence, 3) differently shaped mesonotum and propodeum, 4) far less strongly impressed promesonotal suture and metanotal groove, 5) terminal four, rather than three, antennal segments forming a weak club, 6) more strongly squamiform petiole, which is also more arcuate in dorsal view, 7) less developed clypeal structure (in Asphinctopone silvestrii and Asphinctopone differens the median clypeal lobe is bounded by distinct sharp angles, is distinctly though shallowly concave on either side of the more acutely rounded median projection and is relatively broader at about 0.40 x HW), 8) the lack of a tooth-like process on the inner basal margin of the mandible and 9) darker colour.

Distribution
This taxon was described, and is only known, from Central African Republic.

Biology
Asphinctopone is one of the most rarely collected and least known small ponerine genera of the Afrotropical region. Specimens are seldom found and most samples recovered consist of only one or two workers. As a measure of its rarity, a survey of leaf litter in Ghana (Belshaw & Bolton, 1994) recorded 43,824 individual ants, of which only 5 (about 0.01%) were Asphinctopone. Despite this rarity, the genus is widespread in wet forest zones in leaf litter, topsoil, pieces of rotten wood and rotting vegetation on the forest floor. One worker has been found foraging in a fallen, abandoned termitary (Dejean et al., 1996). Beyond this nothing is known of its biology. Its specialised morphology implies that it may be prey-specific, but in reality its victims remain unknown. (Bolton and Fisher 2008)

Nomenclature

 *  differens. Asphinctopone differens Bolton & Fisher, 2008a: 59, figs. 1c,d; 2b,d (w.) CENTRAL AFRICAN REPUBLIC.

Description
Holotype. TL 3.7, HL 0.82, HW 0.66, CI 81, SL 0.61, SI 92, PW 0.48, WL 1.06. Answering the description of Asphinctopone silvestrii but differing as follows.

Side of propodeum entirely densely irregularly sculptured.

Dorsum of propodeum with a pelt of fine short pubescence that is erect and weakly curved.

In addition, pubescence on the pronotum and mesonotum is more dense and more elevated than in silvestrii. The propodeal dorsum in profile is longer and flatter than in any silvestrii specimen examined, but the latter shows variation in the shape of the propodeum, and as only a single specimen of Asphinctopone differens is known it is impossible to tell if the sclerite also shows variation here. In differens the dorsal margin of the anepisternum is distinctly concave, whereas in all known silvestrii specimens it is flat to very feebly sinuate.

Type Material
Holotype worker, Central African Republic: P.N. Dzanga-Ndoki, 37.9 km. 169°S Lidjombo, 2°22’N, 16°10’E, 360 m., 21.v.2001, #4130(30), CASENT 0417143, sifted litter, rainforest (B.L. Fisher).