Tetramorium voasary Hita, 2012

Hita Garcia, F. & B. L. Fisher, 2012, The ant genus Tetramorium Mayr (Hymenoptera: Formicidae) in the Malagasy region - taxonomic revision of the T. kelleri and T. tortuosum species groups., Zootaxa 3592, pp. 1-85 : 45-47

Tetramorium voasary Hita Garcia & Fisher sp. n.

(Figs. 60, 71, 72, 99, 100, 101, 141)

Holotype worker, MADAGASCAR, Toamasina, Montagne d'Anjanaharibe, 19.5 km 27° NNE Ambinanitelo, 15.17833 S, 49.635 E, 1100 m, montane rainforest, canopy moss and leaf litter, collection code BLF08213, 12.-16.III.2003 (B.L. Fisher, C. Griswold et al.) (CASC: CASENT0247162). Paratypes, 11 workers with same data as holotype (CASC: CASENT0497903; CASENT0497904; CASENT0497905; CASENT0497906); and one worker with same data as holotype except sampled from beating low vegetation and collection code BLF08151 (CASC: CASENT0489080).

Diagnosis

Tetramorium voasary can be clearly distinguished from the remainder of the species complex by the following character combination: eyes moderately sized (OI 21-24); propodeal spines long to very long (PSLI 35-39); petiolar node rectangular nodiform but with relatively rounded anterodorsal and posterodorsal angles; posterodorsal corner of petiolar node not strongly protruding posteriorly; postpetiole in dorsal view usually slightly longer than wide, rarely as wide as long or longer than wide (DPpI 95-101); body uniform bright orange in colour.

Description

HL 0.94-1.23 (1.07); HW 0.87-1.15 (0.98); SL 0.70-0.99 (0.81); EL 0.18-0.27 (0.23); PH 0.49-0.59 (0.53); PW 0.69-0.80 (0.73); WL 1.20-1.49 (1.36); PSL 0.36-0.46 (0.39); PTL 0.32-0.36 (0.35); PTH 0.37-0.42 (0.40); PTW 0.29-0.34 (0.31); PPL 0.34-0.42 (0.38); PPH 0.36-0.43 (0.39); PPW 0.34-0.41 (0.38); CI 88-93 (92); SI 80-89 (82); OI 21-24 (23); DMI 52-58 (54); LMI 38-42 (39); PSLI 35-39 (37); PeNI 41-47 (43); LPeI 85-93 (89); DPeI 85-94 (90); PpNI 48-55 (52); LPpI 90-104 (97); DPpI 95-101 (98); PPI 113-125 (120) (ten measured).

Head distinctly longer than wider (CI 88-93). Posterior head margin weakly concave. Anterior clypeal margin medially impressed. Frontal carinae strongly developed, diverging posteriorly, and ending at corners of posterior head margin. Antennal scrobes weakly developed, shallow, narrow, and without defined posterior and ventral margins. Antennal scapes comparatively moderately long, not reaching posterior head margin (SI 80-89). Eyes small to moderately sized (OI 21-24). Mesosomal outline in profile flat to weakly convex, moderately marginate from lateral to dorsal mesosoma; promesonotal suture and metanotal groove absent; mesosoma comparatively stout and high (LMI 38-42). Propodeal spines long to very long, spinose, and acute (PSLI 35-39); propodeal lobes short, triangular, and rounded, rarely acute. Petiolar node in profile rectangular nodiform with fairly rounded margins, around 1.1 to 1.2 times higher than long (LPeI 85-93), anterior and posterior faces approximately parallel, anterodorsal and posterodorsal margins approximately at same height, dorsum weakly to moderately convex; node in dorsal view around 1.1 to 1.2 times longer than wide (DPeI 85-94). Postpetiole in profile globular, ranging from weakly longer than high to 1.1 times higher than long (LPpI 90-104); in dorsal view ranging from weakly longer than wide to feebly wider than long (DPpI 95-101). Postpetiole in profile appearing approximately as voluminous as petiolar node, in dorsal view approximately 1.1 to 1.3 times wider than petiolar node (PPI 113-125). Mandibles distinctly longitudinally rugose, sometimes weakly so; sculpture on clypeus variable, often longitudinally rugulose with three to five rugulae, sometimes more irregularly rugulose; cephalic dorsum between frontal carinae with seven to ten longitudinal rugae, rugae often broken or with cross-meshes; lateral and ventral head mostly reticulate-rugose. Mesosoma laterally and dorsally mainly longitudinally rugose. Forecoxae usually completely unsculptured, smooth, and shiny, sometimes with partial superficial sculpture. Waist segments rugulose, usually longitudinally so. Generally ground sculpture everywhere on body faint to absent. First gastral tergite unsculptured, smooth, and shining. All dorsal surfaces of head, mesosoma, waist segments, and gaster with abundant, long, and fine standing hairs. Anterior edges of antennal scapes with suberect to erect standing hairs. Body of bright orange to light orange brown colour.

Notes

This new species is distributed in the rainforests and montane rainforests of eastern Madagascar from BefotakaMidongo in the south to Makirovana in the northeast. The distribution range is comparatively large, but localities where T. voasary was encountered are often widely separated. Despite being known from approximately ten localities, T. voasary was collected relatively rarely with less than 25 specimens in total. One explanation might be that the species lives and forages in vegetation; it was mostly collected from lower vegetation, and only rarely from the ground or leaf litter.

Due to its well-developed eyes (OI 21-24), T. voasary is unlikely to be mistaken for T. electrum, T. elf, T. isectum, T. isoelectrum, or T. nify since they all have much smaller eyes (OI 15-19). The remaining three species, T. ala, T. andohahela , and T. andrei, all have a petiolar node with well-defined antero- and posterodorsal margins while the node of T. voasary has fairly rounded margins. This character is shared with T. elf and T. isoelectrum, although they are not likely to be confused with T. voasary. Apart from the small eyes mentioned above, the first two also have extremely long propodeal spines (PSLI 58-64) that contrast with the shorter spines of T. voasary (PSLI 35-39).

Etymology

The species epithet is an arbitrary combination of letters.

Material examined

MADAGASCAR: Antsiranana, Makirovana forest, 14.1707 S, 49.9541 E, 415 m, rainforest, 28.IV.2011 (B.L. Fisher et al.); Fianarantsoa, Foret d'Ambalagoavy Nord, Ikongo, Ambatombe, 21.8275 S, 47.3389 E, 625 m, 1.XII.2000 (R. Harin'Hala & M.E. Irwin); Fianarantsoa, Parc National Befotaka-Midongy, Papango 27.7 km S Midongy-Sud, Mount Papango,23.83517 S, 46.96367 E, 940 m, rainforest, 13.-15.XI.2006 (B.L. Fisher et al.); Fianarantsoa, Réserve Speciale Manombo 24.5 km 228° Farafangana, 23.0158 S, 47.719 E, 30 m, rainforest, 22.IV.2006 (B.L. Fisher et al.); Fianarantsoa, Ranomafana, 21.25 S, 47.3667 E, in forest along riverbank, 1.III.1994 (A. Pauly); Fianarantsoa, Ranomafana National Park, Talatakely, 30.X.-20.XI.1998 (V.F. Lee & K.J. Ribardo); Fianarantsoa, Parc National de Ranomafana, Vatoharanana River, 4.1 km 231° SW Ranomafana, 21.29 S, 47.4333 E, 1100 m, montane rainforest, 27.-31.III.2003 (B.L. Fisher, C. Griswold et al.); Toamasina, Ambatovy, 12.4 km NE Moramanga, 18.8496 S, 48.2947 E, 1010 m, 3.-6.III.2007 (B.L. Fisher et al.); Toamasina, Amparihibe, 15° 2' S, 49° 34' E, II.-III.2003 (K.A. Jackson & D. Carpenter); Toamasina, Montagne d'Anjanaharibe, 19.5 km 27° NNE Ambinanitelo, 15.1783 S, 49.635 E, 1100 m, montane rainforest, 12.-16.III.2003 (B.L. Fisher, C. Griswold et al.); Toamasina, Torotorofotsy, 18.8708 S, 48.3474 E, 1070 m, montane rainforest, marsh edge, 24.III.2004 (Malagasy ant team).