Pachycondyla tahary Rakotonirina and Fisher

Rakotonirina, Jean Claude & Fisher, Brian L., 2013, Revision of the Pachycondyla sikorae species-group (Hymenoptera: Formicidae) in Madagascar, Zootaxa 3683 (4), pp. 447-485 : 476-478

Pachycondyla tahary Rakotonirina and Fisher , sp. nov.

( Figures 27 , 61, 62, 63 , 79 )

Holotype worker: Madagascar, Toamasina, RS Ambatovaky, Sandrangato River , -16.7727, 49.2655, 450 m, rainforest, ex rotten log, 20 Feb 2010 (B.L. Fisher et al.), collection code: BLF24323, specimen code: CASENT0162668 ( CASC).

WORKER. Diagnosis: Anteromedial margin of clypeus projecting anteriorly as a blunt angle; with head in fullface view, lateral margins before level of anterior margin of eye strongly curving towards base of mandibles; in lateral view, distance between eye and base of mandible roughly less than twice the maximum diameter of eye; antennal scape attaining posterior cephalic margin; posterolateral margins of propodeum and petiolar node with a series of sharp teeth or denticles; mesopleural suture indistinct, while broad and discontinuous lines in different directions may be present; second gastral tergite punctate to sparsely punctate, pubescence absent or reduced on first and second gastral tergites; head behind the level of eye mostly smooth and shiny on faintly effaced reticulatepunctate sculptures.

Measurements (8 specimens): HW: 1.32–1.57, HL: 1.39–1.67, CI: 94–99, SL: 0.98–1.30, SI: 71–83, PW: 0.98–1.17, WL: 1.79–2.34, NH: 0.84–1.08, NL: 0.63–0.85, NW: 0.81–1.09, DNI: 122–132, LNI: 123–139.

Description: Head subquadrate, roughly as long as broad, sides nearly parallel posteriorly before curving abruptly from level of eyes towards base of mandibles; posterior border with weak median excision. Head dorsum reticulate-punctate, with large, smooth, and shiny spaces between punctures; sculptures become punctate and sparsely punctate near posterior margin and sides, respectively. Eyes medium, protruding from head surface, with more than 25 ommatidia; distance between eye and base of mandible approximately less than twice the maximum diameter of eye. Antennal scape barely surpassing posterior margin of head. Median lobe of clypeus convex, anterior margin projecting anteriorly into a median convexity or blunt angle. Mandibles smooth and shiny, with scattered piliferous punctures; masticatory margins with ten teeth or denticles.

With mesosoma in dorsal view, metanotal groove absent; mesosoma dorsum mostly smooth between scattered punctures; blunt rugae or tubercles present on pronotum. In lateral view, mesopleural sulcus indistinct, and a broad superficial impression may be present; posterolateral border of propodeum with a series of teeth or tubercles. In profile, lower half of posterolateral margin of petiole node with a series of teeth or tubercles; dorsum and lateral surface of node coarsely bluntly tuberculate. In dorsal view, lateral margins of node forming a convex line to generally rounded anterior border; posterior margin slightly convex. Anterior face of first gastral segment without shallow cavity; first and second gastral tergites punctate laterally, the punctures becoming widely spaced dorsally. Erect hairs long and thin; pubescence abundant on head and pronotum, but gradually reduced or absent from rest of mesosoma dorsum to second gastral tergite. Color black with bluish or opalescent reflection; appendages and tip of gaster brown.

Queen: unknown.

Distribution and biology: Endemic to Madagascar, P. tahary is only recorded from the rainforests of the RS Ambatovaky in the east of the island ( Fig. 79 ). It forages mainly through the leaf litter and nests in rotten logs.

Additional material examined: Province Toamasina: RS Ambatovaky, Sandrangato river, 360 m, rainforest (B.L. Fisher et al.) ( CASC); RS Ambatovaky, Sandrangato River, -16.7727, 49.2655, 450 m, rainforest (B.L. Fisher et al.) ( CASC); RS Ambatovaky, Sandrangato River, -16.7633, 49.2669, 520 m, rainforest (B.L. Fisher et al.) ( CASC); RS Ambatovaky, Sandrangato River, -16.8175, 49.295, 360 m, rainforest (B.L. Fisher et al.) ( CASC); Sahafina Forest 11.4 km W Brickaville, -18.8144, 48.9621, 140 m, rainforest (B.L. Fisher et al.) ( CASC).

Figures

FIGURES 26 – 27. Mesosoma in lateral view; Fig. 26: mesopleural suture distinctly continuous and narrowly impressed (CASENT 0317590); Fig. 27: mesopleural suture indistinct (CASENT 0162668: holotype).

FIGURES 61 – 63. Worker caste of Pachycondyla tahary: lateral and dorsal view of body and full-face view of head, holotype CASENT 0162668.

FIGURES 76 – 81. Distribution maps of the P. sikorae species-group in Madagascar. Fig. 76: P. m i a l y (triangle) and P. n o s y (circle); Fig. 77: P. ro v a n a; Fig. 78: P. sikorae; Fig. 79: P. t a h a r y; Fig. 80: P. vohitravo; Fig. 81: P. z o ro.