Vitsika crebra 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 : 78

Vitsika crebra Bolton & Fisher sp. n.

(Figs 90-92, Map 152)

WORKER (holotype in parentheses). TL 3.0-3.7 (3.5), HL 0.69-0.84 (0.80), HW 0.55-0.69 (0.65), CI 79-84 (81), SL 0.49-0.61 (0.60), SI 86-91 (91), PW 0.42-0.54 (0.51), WL 0.84-1.07 (1.02) (25 measured).

Eye with 7-8 rows of ommatidia, and with 9-10 ommatidia in the longest row; EL 0.18-0.23 (EL/HW 0.30-0.34). Eye in profile not tear-drop shaped, not coming to a point anteriorly; the anterior and posterior curvatures of the eye almost equally convex. MfL 0.60-0.76 (MfL/HW 1.03-1.15). Oblique costulae on mesopleuron sparse and weak. In profile, the dorsal outline of the propodeum forms an even slope from just behind the metanotal groove to the base of the spine. Propodeal declivity lacks transverse costulae. Diameter of annulus of propodeal spiracle is slightly less than, to about equal to, the thickness of the short propodeal spine at its midlength. Petiole node in posterior view low and broad, its posterior surface usually with some reticulate-punctulate sculpture, at least on the lower half. Height of petiole node in posterior view (from midpoint of the dorsal margin of the foramen to the apex) 0.75-0.90 x its maximum width. In dorsal view postpetiole 1.33-1.42 x broader than long; maximum width of postpetiole 1.95-2.25 x the length of a propodeal spine; maximum width of postpetiole 1.25-1.50 x the distance between the apices of the propodeal spines. Disc of postpetiole entirely sculptured with reticulate-punctulation, and also usually with some weak rugulae present. Full adult colour uniform yellow.

QUEEN (gyne). Only alates known; may be polygynous as more than one queen appears in some series. HL 0.80-0.86, HW 0.68-0.72, CI 84-86, SL 0.56-0.60, SI 81-85, PW 0.58-0.62, WL 1.14-1.18, MfL 0.72-0.76 (4 measured). As in the worker the postpetiole is very broad and entirely sculptured dorsally, and the propodeal spines are short.

MALE. HL 0.65, HW 0.54, CI 83, SL 0.27, SI 50, mesoscutum width at maximum 0.52, WL 1.00, EL 0.27, MfL 0.64 (1 measured). Propodeal dorsum finely punctulate and with scattered fine, longitudinal rugulae. Propodeal dorsum without a median longitudinal carina, but upper half of declivity with a median carina present; a fine rugula on each side separates the declivity from the side of the propodeum. Propodeum in profile unarmed, the rounded angle between dorsum and declivity surmounted by a an extremely low, rounded cuticular crest. Postpetiole in dorsal view broader than long, the surface finely punctulate-shagreenate. Postpetiole in profile longer than high. Colour yellow.

Holotype worker, Madagascar: Prov. Mahajanga, P.N. Tsingy de Bemaraha, 10.6 km. 123° ESE Antsalova, 150 m., 18°43'S, 44°43'E, 16-20.xi.2001, sifted litter, tropical dry forest, BLF 4432(1), CASENT0473810 (Fisher et al.) (CASC).

Paratypes. 7 workers and 2 dealate queens, with same data as holotype and all BLF 4432: workers, (6) CASENT0473811, (10) CASENT0473813, (12) CASENT0473814, (14) CASENT0473815, (18) CASENT0473818, (19) CASENT0473819, (40) CASENT0473809; queens, (15) CASENT0473816, (27) CASENT0473822 (CASC). [The nine paratype specimens were selected from leaf litter series BLF 4432, which contains another 18 workers and 2 dealate queens, all in CASC.]

One of the most easily recognised species of Vitsika . The combination of yellow colour, short propodeal spines, and very broad postpetiole that is uniformly densely sculptured dorsally, is not repeated anywhere else in the genus.

All examples of this species originate in tropical dry forest. They have been found as ground foragers, in pitfall traps, in litter samples, in rotten logs, in dead twigs above the ground, and by beating low vegetation.

Non-paratypic material examined. Madagascar: Prov. Mahajanga, Tsingy de Bemaraha, ESE Antsalova (Fisher et al.); Prov. Mahajanga, Tsingy de Bemaraha, E Bekopaka (Fisher et al.); Prov. Mahajanga, Tsingy de Bemaraha, ENE Bekopaka (Fisher et al.); Prov. Mahajanga, Foret de Tsimembo, NNW Soatana (Fisher et al.); Prov. Mahajanga, Res. Bemarivo, SW Besalampy (Fisher et al.); Prov. Mahajanga, P.N. Ankarafantsika, Ampijoroa, NW Andranofasika (Rabeson et al.); Prov. Mahajanga, P.N. Namoroka, NW Vilanandro (Fisher et al.); Prov. Mahajanga, P.N. Baie de Baly, NNW Soalala (Fisher et al.); Prov. Mahajanga, Res. forest Beanka (B.L. Fisher), Prov. Antsiranana, Foret Anabohazo, WSW Maromandia (Fisher et al.).