Pachycondyla mialy 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 : 469-470

Pachycondyla mialy Rakotonirina and Fisher , sp. nov.

( Figures 2 , 9 , 14 , 49, 50, 51 , 76 )

Holotype worker: Madagascar, Fianarantsoa, PN Ranomafana , Vatoharanana River , 4.1 km 231° SW Ranomafana, -21.29, 47.4333, 1100 m, montane rainforest, ex rotten log, 27–31 Mar 2003 (Fisher, Griswold et al.), collection code BLF08535, specimen code CASENT0497667 ( CASC).

Paratype: 1 worker with the same data as holotype but specimen coded as CASENT0009727 ( CASC).

WORKER. Diagnosis: Anterior margin of clypeus wide and straight, with median notch; eyes small, with seven to eight ommatidia; metanotal groove absent; posterior face of petiolar node with sparse pubescence and lacking numerous slender hairs; anterior face of first gastral segment not forming a shallow cavity; antennal scape and outer surface of each tibia covered with shorter, erect hairs.

Measurements (2 specimens): HW: 1.15, HL: 1.38–1.41, CI: 81–83, SL: 0.94–0.95, SI: 82, PW: 0.87–0.88, WL: 1.78, NH: 0.59–0.62, NL: 0.46–0.47, NW: 0.63–0.66, DNI: 137–140, LNI: 125–134.

Description: Head distinctly longer than broad, widest at mid-length; posterior margin weakly medially excised; the dorsum with dense and fine reticulate punctures; anterior third of lateral surface punctate and sparsely punctulate posteriorly. Eyes very small, with at most eight ommatidia, and situated in anterior fourth of head. Antennal scape short, not extending beyond posterior cephalic border; length of erect hairs on scape about half of widest portion of scape. Anterior clypeal margin widely transverse and straight, with feeble median excision. Mandibles smooth and shiny between sparse punctures.

With mesosoma in dorsal view, metanotal groove lacking; in profile, dorsal outline of mesosoma simple, approximately a continuous line; posterolateral margin of propodeum covered with narrow lamellae, which project into a blunt angle near the mid-length at about the level of propodeal spiracle; mesopleural suture indistinct. Sculpture of promesonotum punctate; the punctures become more sparse toward the propodeum. With petiole in lateral view, node thick, posterior margin convex; in dorsal view, lateral margins rounding to a convex anterior face; posterior margin slightly excised medially; dorsum of node with scattered punctures. First gastral segment with straight anterior face; first and second gastral tergites laterally coarsely punctate or foveolate and dorsally smooth and shiny between punctures.

Body covered with erect golden pilosity; pubescence abundant on head dorsum, promesonotum, tip of gaster, and appendages, but absent or sparse on the rest of body dorsum. Integument glossy, reddish orange with orange apex of gaster and appendages.

Queen: unknown.

Discussion: One can confound P. m ia ly with P. nosy but workers of the former are smaller, have smaller eyes, no metanotal groove and no mesopleural suture while those of the latter are characterized by a larger body size, larger eyes, the presence of a mesopleural suture and a metanotal groove reduced to a dotted line.

Distribution and biology: This species is recorded only from an elevation of 1100 m in the PN Ranomafana. Two worker specimens were collected from rotten logs.

Figures

FIGURES 2 – 3. Shape of the clypeus with head in full-face view; Fig. 2: anterior margin widely transverse and straight with feeble median notch (CASENT 0497667); Fig. 3: anterior margin medially convex or bluntly angulate (CASENT 0050524).

FIGURES 8 – 9. Mesosoma in dorsal view; Fig. 8: metanotal groove deeply impressed (CASENT 0034340: holotype); Fig. 9: metanotal groove lacking (CASENT 0497667).

FIGURES 14 – 15. Mesosoma in dorsal view; Fig. 14: metanotal groove absent (CASENT 0497667); Fig. 15: metanotal groove as a dotted line (CASENT 0231239: holotype).

FIGURES 49 – 51. Worker caste of Pachycondyla mialy: lateral and dorsal view of body and full-face view of head, holotype CASENT 0497667.

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.