Prionopelta vampira Overson & Fisher

Overson, Rick & Fisher, Brian L., 2015, Taxonomic revision of the genus Prionopelta (Hymenoptera, Formicidae) in the Malagasy region, ZooKeys 507, pp. 115-150 : 133-134

Taxon classification Plantae Hymenoptera Formicidae

Prionopelta vampira Overson & Fisher sp. n. Figs 1B, 2A, C, 11

Type material.

Holotype, pinned worker, MADAGASCAR, Antsiranana, Forêt d’Analabe, 30.0 km 72° ENE Daraina, 13.08333°S, 49.90833°E, 30 m, littoral rainforest, sifted litter (leaf mold, rotten wood), collection code BLF09426, 27.xi.2003 (B.L. Fisher et al.) (CASC: CASENT0041504). Paratypes, three pinned workers with same data as holotype (CASC: CASENT0041500; CASENT0041501; CASENT0041502).

Diagnosis.

Prionopelta vampira is the only member of the genus from the Malagasy region in which workers entirely lack any visible metanotal suture when viewed dorsally; additionally the posterior propodeal edge is noticeably more concave in dorsal view than any other Malagasy Prionopelta .

Worker measurements

(N=8). HL 0.49-0.53 (0.5); HW 0.41-0.45 (0.42); SL 0.27-0.31 (0.28); WL 0.55-0.62 (0.58); PetL 0.19-0.23 (0.21); PetW 0.24-0.26 (0.25); T1W 0.35-0.39 (0.37); CI 81.78-85.31 (83.78); PI 103.96-130.2 (120.71); SI 64.25-69.36 (67.33).

Worker description.

Highest cephalic index on average of Malagasy Prionopelta (CI 81.78-85.31 (83.78); posterior margin of the head with slight notch medially in full-face view; cephalic foveae shallow, large, and widely spaced; directly adjacent cephalic foveae either completely lacking, or very rare; if any foveae are adjacent, then always with only 2-3 foveae connected, and these usually always medially on the head in full-face view; majority of cephalic foveae separated by 1-3 foveal diameters, appear cleanly scooped from the shining integument, and lack raised margins; median cephalic band devoid of foveae is uniformly broad, and not swelling above the integument; apical tooth very long, longest of all Malagasy Prionopelta , over four times the length of the third apical tooth measured from base to tip (Fig. 2C); sculpture of the dorsum of the mesosoma consisting of large, shallow foveae which are widely spaced at 2-3 foveal diameters with punctures present between foveae; no metanotal suture present in dorsal view, but rather a shining surface with no clear distinction between propodeum and mesonotum; in a few specimens, a slightly perceptible depression is sometimes visible at the site of the metanotal suture, with associated notches on the lateral edges of the dorsum of the mesosoma, but this depression always lacks scarring; in lateral view, mesopropodeal suture weak, appearing as a gradual depression rather than a scar; posterior propodeal edge seen dorsally strongly concave; sharp lamellae of the posterior propodeum present.

Etymology.

The name of this species is inspired by the vampire-like nature of its exceptionally long apical tooth. The species epithet is a Latinized adjective of the German and Hungarian word “vampir”.

Distribution and ecology.

This species is almost entirely restricted to northern Madagascar where it is found in litter in rainforest, littoral rainforest, and montane rainforest from 25-1200 meters of elevation. Intriguingly, Prionopelta vampira has also been collected at a single, highly disjunct site in far southeastern Madagascar 1048 km to the south near Enakara in the province of Toliara (Fig. 13).

Taxonomic notes.

This species, which has similar cephalic scupturing to Prionopelta xerosilva , is otherwise unmistakable due to its extremely long apical tooth, lack of a metanotal suture, and strongly concave posterior propodeal edge when viewed dorsally.

Non-type material.

MADAGASCAR: Antsiranana, Ampasindava, Andranomatavy Forest, 13.669°S, 47.9877°E, 149 m, disturbed dry forest, 6.x.2013 (B.L.Fisher et al.); Antsiranana, Ampasindava, Andranomatavy Forest, 13.663°S, 47.9794°E, 543 m, disturbed dry forest, 6.x.2013 (B.L.Fisher et al.); Antsiranana, Forêt Ambato, 26.6 km 33° Ambanja, 13.4645°S, 48.5517°E, 150 m, rainforest, 8.xii.2004 (B.L.Fisher); Antsiranana, Forêt d’ Andavakoera, 21.4 km 75° ENE Ambilobe; 4.6 km 356° N Betsiaka, 13.1183°S, 49.23°E, 425 m, rainforest, 15.xii.2003 (B.L.Fisher); Antsiranana, Forêt d’Ampombofofo, 12.0995°S, 49.3387°E, 25 m, littoral forest, 21.xi.2007 (B.L.Fisher et al.); Antsiranana, Forêt d’Analabe, 30.0 km 72° ENE Daraina, 13.0833°S, 49.9083°E, 30 m, littoral rainforest, 27.xi.2003 (B.L.Fisher); Antsiranana, Makirovana forest, 14.1707°S, 49.9541°E, 225 m, rainforest, 4.v.2011 (B.L.Fisher et al.); Antsiranana, Nosy Be, Réserve Naturelle Intégrale de Lokobe, 6.3 km 112° ESE Hellville, 13.4193°S, 48.3312°E, 30 m, rainforest, 19.iii.2001 (Fisher, Griswold et al.); Toliara, 11 km NW Enakara, Rés. Andohahela, 24.5667°S, 46.8333°E, 800 m, rainforest, 17.xi.1992 (B.L.Fisher).