Vitsika manifesta Bolton & Fisher

Bolton, Barry & Fisher, Brian, 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), pp. 1-99 : 84-85

Vitsika manifesta Bolton & Fisher sp. n.

(Figs 102-104, Map 156)

WORKER (holotype in parentheses). TL 3.3-4.1 (4.0), HL 0.72-0.90 (0.84), HW 0.62-0.76 (0.72), CI 83-88 (86), SL 0.56-0.68 (0.62), SI 80-90 (86), PW 0.48-0.62 (0.58), WL 0.92-1.18 (1.04) (15 measured).

Eye with 5-8 rows of ommatidia, and with 6-10 ommatidia in the longest row; EL 0.15-0.20 (EL/HW 0.23-0.28). MfL 0.68-0.88 (MfL/HW 1.21-1.32). Oblique costulae on mesopleuron conspicuous. Diameter of annulus of propodeal spiracle is usually slightly greater than the thickness of the propodeal spine at its midlength. Propodeal declivity transversely costulate. In posterior view the petiole node tall and slender, its dorsal margin rising to a narrowly rounded median peak. Height of petiole node in posterior view (from midpoint of the dorsal margin of the foramen to the highest point of the node) 1.10-1.23 x its maximum width. In dorsal view postpetiole 1.07-1.15 x broader than long; maximum width of postpetiole 1.00-1.10 x the length of a propodeal spine; maximum width of postpetiole 0.90-1.04 x the distance between the apices of the propodeal spines. Side of petiole node usually, but not always, with longitudinal costulae; when present the costulae tend to overlap onto the posterior surface of the node, at least posterolaterally. Length of postpetiole node less than the height of the segment. Disc of postpetiole mostly smooth, but longitudinal costulae are usually visible laterodorsally. Full adult colour rich reddish brown to dark brown.

QUEEN (gyne). Ergatoid (e.g. CASENT0914197), alate, and intermediate (e.g. CASENT0914198) forms are known. Ergatoid: HL 0.86, HW 0.75, CI 87, SL 0.64, SI 85, PW 0.55, WL 1.12, MfL 0.84. The ergatoid has three ocelli. The mesosoma is almost worker-like except that the mesonotum is slightly enlarged compared to the worker. The mesopleural sulcus is absent. Intermediate: HL 0.84, HW 0.74, CI 88, SL 0.60, SI 81, PW 0.56, maximum length of mesoscutum 0.40, maximum width of mesoscutum 0.40, WL 1.08, MfL 0.78. Three ocelli present. Mesosoma with a full complement of flight sclerites, but the individual sclerites small, considerably reduced from size seen in alate queen, and without trace of wing articulations. Mesopleuron with a transverse sulcus. Alate: HL 0.87, HW 0.79, CI 91, SL 0.64, SI 81, PW 0.68, maximum length of mesoscutum 0.70, maximum width of mesoscutum 0.68, WL 1.30, MfL 0.86. Three ocelli present. Mesosoma with a full complement of full-sized flight sclerites, with wing articulation present. Mesopleuron with a broad transverse sulcus. Note that in all forms most measurements are within the worker range, but in the fully alate form PW and WL are greatly increased. Also, the mesoscutum is much larger in the alate than in the intermediate.

MALE: unknown.

Holotype worker, Madagascar: Prov. Antsiranana, P.N. Marojejy, 25.7 km. 32° NNE Andapa, 21-23.xi.2003, 1575 m., 14°26.7'S, 49°44.5'E, sifted litter, montane rainforest, BLF 9242(9), CASENT0040789 (Fisher et al.) (CASC).

Paratypes. 7 workers with same data as holotype, and all BLF 9242; (L0) CASENT0040797, (4) CASENT0040784, (6) CASENT0040790, (10) CASENT0040791, (13) CASENT0040792, (16) CASENT0040793, (22) CASENT0040795 (CASC, BMNH).

As seen in posterior view, the high, narrow petiole node, whose dorsal margin rises to a narrowly rounded median peak, is immediately diagnostic of manifesta . The height of the node in posterior view (from midpoint of the dorsal margin of the foramen to the highest point of the node) is 1.10-1.23 x its maximum width; i.e. the node is always higher than wide. In all other species of Vitsika , with the node in posterior view the dorsal margin is always flat to broadly, shallowly convex (concave in incisura ). In the remainder of the genus the total range of height of node is 0.66-1.10 x its maximum width. Only labes has an upper value of 1.10, but here the postpetiole node in profile is distinctly longer than the height of the segment.

All material of manifesta is from montane shrubland and rainforest, at considerable altitude (1565-2000 m.). Specimens have been retrieved from litter samples and yellow pan traps.

Non-paratypic material examined. Madagascar: Prov. Antsiranana, P.N. Marojejy, NNE Andapa (Fisher et al.); Prov. Antsiranana, RNI Marojejy, NW Manantenina (E.L. Quinter); Prov. Antsiranana, WSW Befingotra, Res. Anjanaharibe-Sud (B.L. Fisher).