Pachycondyla vazimba Rakotonirina and Fisher

Rakotonirina, Jean Claude & Fisher, Brian L., 2013, Revision of the Pachycondyla wasmannii - group (Hymenoptera: Formicidae) from the Malagasy region, Zootaxa 3609 (2), pp. 101-141 : 131-132

Pachycondyla vazimba Rakotonirina and Fisher , sp. n

( Figures 12 , 48–49 , 63 )

Holotype worker: MADAGASCAR: Mahajanga, Parc National Namoroka, 16.9 km 317° NW Vilanandro, - 16.4067, 45.31, 100 m, ex rotten log, tropical dry forest, 12–16 Nov 2002 (Fisher, Griswold et al.), collection code: BLF06686, specimen code: CASENT0486413 (CASC).

Paratypes: series of 5 workers with the same data as holotype but with specimen codes CASENT0486411, CASENT0247224, CASENT0247225, CASENT0247226, CASENT0247227 (BMNH, MHNG, CASC, PBZT).

Worker diagnosis:

With head in full-face view, antennal scape not surpassing the posterior cephalic margin; dorsum of head and mesosoma not finely striate; basal half of antennal scape rounded; dorsum of mesosoma and petiole node with short and thin erect hairs; junction of propodeal dorsum and declivitous surface at a distinct angle; mesopleural suture absent or incomplete; antennal segments 6, 7, and 8 nearly twice as wide as long; with petiole in dorsal view, the posterior margin broadly concave; anterior half of fourth abdominal tergite (gastral tergite 2) covered with numerous and very dense small punctures between larger ones, mesosoma and petiole node with moderate such sculpture; outer surface of hind tibia usually without erect hairs; integument matte.

Worker measurements (n=10): HL: 1.59–1.75, HW: 1.38–1.50, CI: 85–90, SL: 1.08–1.22, SI: 76–82, PW: 1.06–1.21, WL: 2.04–2.33, NL: 0.75–0.84, NW: 0.91–1.05, NH: 1.05–1.18, DNI: 119–132, LNI: 133–149.

Description:

Worker. Head longer than broad, widest immediately behind level of eyes; sides feebly convex along their length and converging in front of level of eyes; posterior margin weakly medially excised. Compound eyes small, diameter approximately less than half maximum width of scape. Antennal scape with rounded leading edge, not attaining posterior margin of head; antennal segments 6, 7, and 8 nearly twice as wide as long. Anterior margin of clypeus truncated and straight. Mandibles triangular, the apical margins armed with seven to nine teeth or denticles. In lateral view, dorsal outline of mesosoma not continuously convex, but rather roughly straight and interrupted by nearly angulate junction of propodeal dorsum to declivitous surface. Mesopleural sulcus indistinct or absent. Propodeal declivity triangularly shaped and narrower towards the dorsal surface. Basitarsus of hind legs generally rounded, without concavity on basal half of inside surface. With petiole in dorsal view, node anteriorly convex and posteriorly broadly concave. Dorsum of head densely and finely reticulate-punctate to reticulate-rugulose, and interspersed with larger punctures.

Mandibles striate with scattered piliferous pits. Dorsum of mesosoma and petiole node through the fourth abdominal segment densely finely reticulate-punctate, with sparse, shallow, and larger punctures. Sides of mesosoma and node of petiole densely and finely reticulate-rugulose. Lateral portion of abdominal segments 3 and 4 finely reticulate-punctate or with dense, small punctures. Dorsum of mesosoma, petiole node, and gaster covered with slender and short hairs which are usually absent on outer surface of hind tibiae. Body color dark brown to black, with reddish orange appendages and articulations. Integument relatively matte between the large punctures.

Queen. Measurements (n=5): HL: 1.63–1.91, HW: 1.52–1.79, CI: 92–94, SL: 1.13–1.48, SI: 75–86, EL: 0.30–0.35, OI: 19–22, PW: 1.32–1.51, WL: 2.45–2.90, NL: 0.70–0.89, NW: 1.05–1.18, NH: 1.02–1.23, DNI: 123–156, LNI: 131–146. Worker characters are generally duplicated in the queen caste, except the latter is only slightly larger, and the body is covered by denser and more elongate pubescence.

Discussion:

Worker specimens of Pachycondyla vazimba are very similar to those of P. wasmannii , but their smaller size, the indistinct mesopleural suture, the absence of erect hairs on the outer surface of the hind tibia, and the broader than long shape of antennal segments 6, 7, and 8 render P. v a z im b a separable from P. wasmannii .

Distribution and biology:

The distribution of P. v a z i m b a is generally limited to western Madagascar ( Fig. 63 ). This species occurs mostly in the dry forest habitats of the PN Ankarafantsika in the north through Beza-Mahafaly Forest in the south.

Interestingly, along its north-south range it also can be found in the gallery forests of the PN Isalo, Forêt de Mite, and Fiherenana, and in the disjunct montane rainforest of Analavelona. When nesting in rotten logs, dead branches on the ground and in the soil layer, P. v a z i m b a forages most often in leaf litter and infrequently on the forest floor, habits related to its smaller eyes, shorter antennal scape, and shorter legs.

Other material examined:

Antsiranana: Nosy Be, RNI Lokobe, 6.3 km 112° ESE Hellville, -13.41933, 48.33117, 30 m, rainforest (Fisher, Griswold et al.) (CASC); Fianarantsoa: PN Isalo, Sahanafa River, 29.2 km 351° N Ranohira, -22.31333, 45.29167, 500 m, gallery forest (Fisher, Griswold et al.) (CASC); dry wash, 1 km E of Isalo National Park Interpretive Center, -22.62667, 45.35817, 885 m (R. Harin'Hala) (CASC); Mahajanga: Manerinerina, 76.6 km N Antsohihy, -14.10744, 48.11046, 247 m, disturbed forest (B.L. Fisher et al.) (CASC); PN Ankarafantsika, F de Tsimaloto, 18.3 km 46° NE de Tsaramandroso, -16.22806, 47.14361, 135 m, tropical dry forest (Fisher, Griswold et al.) (CASC); Réserve d'Ankoririka, 10.6 km 13° NE de Tsaramandroso, -16.26722, 47.04861, 210 m, tropical dry forest (Fisher, Griswold et al.) (CASC); PN Namoroka, 9.8 km 300° WNW Vilanandro, -16.46667, 45.35, 140 m (Fisher, Griswold et al.) (CASC); PN Namoroka, 17.8 km 329° WNW Vilanandro, -16.37667, 45.32667, 100 m, tropical dry forest (Fisher, Griswold et al.) (CASC); PN Namoroka, 16.9 km 317° NW Vilanandro, -16.40667, 45.31, 100 m, tropical dry forest (Fisher, Griswold et al.) (CASC); RS Bemarivo, 23.8 km 223° SW Besalampy, -16.925, 44.36833, 30 m, tropical dry forest (Fisher, Griswold et al.) (CASC); PN Baie de Baly, 12.4 km 337° NNW Soalala, -16.01, 45.265, 10 m, tropical dry forest (Fisher, Griswold et al.) (CASC); Mahavavy River, 6.2 km 145° SE Mitsinjo, -16.05167, 45.90833, 20 m, gallery forest (Fisher, Griswold et al.) (CASC); PN Tsingy de Bemaraha, 10.6 km ESE 123° Antsalova, -18.70944, 44.71817, 150 m, tropical dry forest on Tsingy (Fisher-Griswold Arthropod Team) (CASC); PN Tsingy de Bemaraha, 2.5 km 62° ENE Bekopaka, Ankidrodroa River, -19.13222, 44.81467, 100 m, tropical dry forest on Tsingy (Fisher-Griswold Arthropod Team) (CASC); PN Tsingy de Bemaraha, 3.4 km 93° E Bekopaka, Tombeau Vazimba , -19.14194, 44.828, 50 m, tropical dry forest (Fisher- Griswold Arthropod Team) (CASC); Toliara: Beza Mahafaly, 27 km E Betioky, -23.65, 44.63333, 135 m, tropical dry forest (B.L. Fisher) (CASC); Beza-Mahafaly, 27 km E Betioky, -23.65, 44.63333, 135 m, tropical dry forest (B.L. Fisher) (CASC); Fiherenana, -23.17694, 43.96083, 100 m, gallery forest (Frontier Project) (CASC); F de Kirindy, 15.5 km 64° ENE Marofandilia, -20.045, 44.66222, 100 m, tropical dry forest (Fisher-Griswold Arthropod Team) (CASC); F de Mite, 20.7 km 29° WNW Tongobory, -23.52417, 44.12133, 75 m, gallery forest (Fisher- Griswold Arthropod Team) (CASC); Makay Mts., -21.21836, 45.3106, 510 m, gallery forest on sandy soil (B.L. Fisher et al.) (CASC); Makay Mts., -21.22336, 45.32628, 480 m, gallery forest on sandy soil (B.L. Fisher et al.) (CASC); Makay Mts., -21.30997, 45.12946, 590 m, dry forest on sandy soil (B.L. Fisher et al.) (CASC); Makay Mts., -21.23343, 45.32913, 460 m, gallery forest with bamboo (B.L. Fisher et al.) (CASC); PN Kirindy Mite, 16.3 km 127° SE Belo sur Mer, -20.79528, 44.147, 80 m, tropical dry forest (Fisher-Griswold Arthropod Team) (CASC); Réserve Beza Mahafaly, Parcel 1, -23.65833, 44.62889, 175 m, dry forest (Alpert et al.) (MCZC); Réserve Beza Mahafaly, Parcel 1, -23.65, 44.63333, 130 m, tropical dry forest (P.S. Ward) (MCZC); Sept Lacs, - 23.52833, 44.15556, 80 m, gallery forest (Frontier Project) (CASC).

Figures

FIGURES 11 – 12. Mesosoma in lateral view; Fig. 11: mesopleural sulcus of P. wasmannii complete; Fig. 12: mesopleural sulcus of P. v a zi m ba indistinct.

FIGURES 48 – 52. Full-face view of the head and lateral view of the body of the worker caste, and form of the femora of the Malagasy Pachycondyla in dorsal view. Figs 48 – 51: Full-face and lateral views of worker: Figs 48 – 49: Pachycondyla vazimba, CASENT 0034562; Figs 50 – 51: Pachycondyla wasmannii, CASENT 0031384; Fig. 52: Dorsal view of P. m a s o a l a showing the flattened basal portion of the femora.

FIGURES 59 – 64. Distributional maps of Pachycondyla wasmannii - group from the Malagasy region. Fig. 59: P. c o m o re n s i s; Fig. 60: P. p e r ro t i; Fig. 61: P. planicornis; Fig. 62: P. tavaratra; Fig. 63: P. v a z i m b a; Fig. 64: P. wasmannii.