Vitsika incisura

Specimens of V. incisura are all from montane rainforest, and were found in a dead twig above the ground, and by beating low vegetation.

Identification
This is the only known Vitsika species in which the dorsal margin of the petiole node is concave medially.

Distribution
Endemic to Madagascar.

Distribution based on Regional Taxon Lists
Malagasy Region: Madagascar.

Castes
Males have yet to be collected.

Nomenclature

 *  incisura. Vitsika incisura Bolton & Fisher, 2014: 82, figs. 96-98, Map 154 (w.q.) MADAGASCAR.

Worker
(holotype in parentheses). TL 3.6–4.2 (4.0), HL 0.84–0.94 (0.93), HW 0.69–0.79 (0.78), CI 82–87 (84), SL 0.62–0.70 (0.68), SI 87–92 (87), PW 0.52–0.63 (0.63), WL 1.02–1.22 (1.20) (11 measured).

Eye with 8–9 rows of ommatidia, and with 9–11 ommatidia in the longest row; EL 0.18–0.22 (EL/HW 0.25–0.28). MfL 0.79–0.90 (MfL/HW 1.11–1.18). Oblique costulae on mesopleuron conspicuous. In profile, the dorsal outline of the propodeum is convex and slopes to the base of the spine. Diameter of annulus of propodeal spiracle is about equal to the thickness of the short propodeal spine at its midlength. With petiole node in posterior view its dorsal margin is impressed to deeply indented medially; at its maximum extent the indentation is so marked that the remainder of the margin forms a blunt projection on each side of the indentation. Height of petiole node in posterior view (from midpoint of the dorsal margin of the foramen to a line that spans the highest points of the node) 0.66–0.80 × its maximum width. In dorsal view postpetiole 1.30–1.50 × broader than long; maximum width of postpetiole 0.94–1.05 × the length of a propodeal spine; maximum width of postpetiole 0.85–1.00 × the distance between the apices of the propodeal spines. Disc of postpetiole entirely smooth. Full adult colour dark brown to blackish brown.

Queen
(gyne). Only an ergatoid specimen known (CASENT0178899). HL 0.90, HW 0.74, CI 82, SL 0.66, SI 89, PW 0.60, WL 1.14, MfL 0.84. The ergatoid has three ocelli, but the mesosoma is almost worker-like. The mesonotum is slightly enlarged compared to the worker, and the track of the promesonotal suture is visible. As in the worker the dorsal margin of the petiole node is broadly excavated medially.

Type Material
Holotype worker, Madagascar: Prov. Antsiranana, R.S. Manongarivo, 17.3 km. 218° SW Antanambao, 1580 m., 14°01.3’S, 48°25.1’E, 27.x.1998, beating low vegetation, montane rainforest, BLF 1972(18)-4 (no CASENT number) (B.L. Fisher). Paratypes. 4 workers with same data as holotype, but 2 workers BLF 1972(24)-5 (no CASENT number), 1 worker BLF 1972(20) CASENT0004212, 1 worker BLF 1972(21) CASENT0127743 (CASC).

References based on Global Ant Biodiversity Informatics

 * Bolton B., and B. L. Fisher. 2014. The Madagascan endemic myrmicine ants related to Eutetramorium (Hymenoptera: Formicidae): taxonomy of the genera Eutetramorium Emery, Malagidris nom. n., Myrmisaraka gen. n., Royidris gen. n., and Vitsika gen. n. Zootaxa 3791(1): 1-99.