Vicinopone conciliatrix

The lone representative of the genus Vicinopone. Bolton and Fisher (2012) - V. conciliatrix appears to be a quite widely distributed but rare species. Its rarity is more likely apparent than real because it nests and forages in trees, rarely if ever coming down to the ground. Its type-locality at Tafo, in Ghana, was within the grounds of the Cocoa Research Institute of Ghana, where a nest of the species was discovered in a thin twig of a small cocoa tree, about 2 metres above the ground, in moderate shade. The nest contained 103 workers, 2 dealate queens and a number of brood. A second, smaller nest was also found at Tafo the following year, located just a few metres from the first, but the species does not appear to have been found there again. Brown (1975) recorded two paratypes from the Democratic Republic of Congo and Yanoviak et al. (2007) retrieved conciliatrix from forest canopy in Gabon. Recently, Peter Hawkes (AFRC) has sent us excellent photographs of a hand-collected specimen found in primary forest in Tanzania (Lindi Region, Ndimba Forest Reserve, 2008 (Hawkes, Mlacha & Ninja)).

Identification
This is the only species in the genus Vicinopone.

Bolton and Fisher (2012) - In major details of morphology, striking contrasts between Vicinopone and all species of Simopone include the following (the state considered apomorphic is italicised).

1 Palp formula is 3,2 in Vicinopone, as opposed to 6,4 or more rarely 5,3 in Simopone.

2 Antennae have 12 antennomeres in Vicinopone, as opposed to 11 antennomeres in Simopone.

3 Scape, when laid straight back, reaches the posterior margin of the eye in Vicinopone, as opposed to the anterior margin of the eye in Simopone (SI 57–67 in Vicinopone, SI 33–56 in Simopone).

4 Ocelli are absent in Vicinopone, as opposed to present in Simopone.

5 Eyes are shifted very far forward in Vicinopone, as opposed to being near or behind the midlength in Simopone (EP 0.32–0.41 in Vicinopone, EP 0.68–1.91 in Simopone).

6 A differentiated posterior (occipital) surface to the head occurs in Vicinopone, as opposed to the lack of such a surface in Simopone.

7 Pre-occipital carina (that extends down the posterolateral margin of the head and onto the ventral surface) runs right across the ventral surface to intersect the ventral midline in Vicinopone, as opposed to the carina terminating well before it approaches the ventral midline in Simopone.

8 Metabasitarsus lacks a ventral glandular groove in Vicinopone, as opposed to the universal presence of such a groove in Simopone.

9 AII (petiole) tergite in dorsal view is elongate and barrel-shaped in Vicinopone, as opposed to flattened and laterally marginate in Simopone (AIIW/AIIL 0.68–0.75 in Vicinopone, AIIW/AIIL 0.79–1.30 in Simopone). 10 Cinctus of AIV is cross-ribbed in Vicinopone, as opposed to smooth in Simopone.

Distribution based on Regional Taxon Lists
Afrotropical Region: Democratic Republic of Congo, Gabon, Ghana, Tanzania, Uganda.

Castes
The workers are said to be size-variable, suggesting a polymorphic worker caste. Also: Bolton and Fisher (2012) - there is allometric variation in the size of the eyes, which become relatively larger with increased size. In the smallest workers measured (HW 0.32) the ratio EL/HW is 0.31. As HW increases the ratio increases, until in the largest workers (HW 0.42), EL/HW is 0.45. In full-face view the outer margins of the eyes of the smallest workers just graze the outline of the side of the head, whereas in larger workers the anterior halves of the outer margins of the eyes clearly interrupt the outlines of the sides.

Nomenclature

 *  conciliatrix. Simopone conciliatrix Brown, 1975: 79, figs. 11-13 (w.q.) GHANA. Combination in Vicinopone: Bolton & Fisher, 2012: 74.

Worker
Bolton and Fisher (2012) - Measurements: HL 0.53–0.68, HW 0.32–0.42, SL 0.18–0.28, EL 0.10–0.19, PW 0.22–0.32, AIIW 0.20–0.28, AIIL 0.24–0.38, AIIIW 0.26–0.37, AIIIL 0.24–0.38, WL 0.60–0.82, MFL 0.27–0.40, CI 59–63, SI 57–67, EL/HW 0.31–0.45, EP 0.32–0.41, AIIW/AIIL 0.68–0.75, AIIIW/AIIIL 0.95–1.08 (10 measured).

Type Material
Bolton and Fisher (2012) - Simopone conciliatrix Holotype worker, paratype workers and paratype queens (dealate), GHANA: Tafo, 27.xi.1970, hollow cocoa twig, on tree (B. Bolton); paratype workers, DEMOCRATIC REPUBLIC OF CONGO (“Belg. Congo” on data label): Yangambi, Réserve Intégrale Riv. “Luco”, 6.x.1949, C-1265 (A. Raignier & J. van Boven) [examined].