Tetramorium vony Hita Garcia & Fisher, 2012

Garcia, Francisco Hita & Fisher, Brian L., 2012, The ant genus Tetramorium Mayr (Hymenoptera: Formicidae) in the Malagasy region — taxonomy of the T. bessonii, T. bonibony, T. dysalum, T. marginatum, T. tsingy, and T. weitzeckeri species groups, Zootaxa 3365, pp. 1-123 : 52-55

Tetramorium vony Hita Garcia & Fisher sp. n.

(figs 40, 42, 44, 66, 67, 68)

Holotype worker, MADAGASCAR, Antsiranana, Réserve Spéciale de l'Ankarana , 13.6 km 192° SSW Anivorano Nord, 12.8636 S, 49.2258 E, 210 m, tropical dry forest, beating low vegetation, collection code BLF03016, 16.– 21.II.2001 (B.L. Fisher, C. Griswold et al.) ( CASC: CASENT0404272 ) . Paratypes, 43 workers with same data as holotype ( BMNH: CASENT0404282 ; CASENT0404310; CASC: CASENT0404270 ; CASENT0404271; CASENT0404275; CASENT0404276; CASENT0404279; CASENT0404280; CASENT0404281; CASENT0404286; CASENT0404287; CASENT0404288; CASENT0404290; CASENT0404291; CASENT0404292; CASENT0404293; CASENT0404297; CASENT0404298; CASENT0404299; CASENT0404301; CASENT0404304; CASENT0404305; CASENT0404306; CASENT0404308; CASENT0404309; CASENT0404311; CASENT0404312; CASENT0404320; CASENT0404321; CASENT0404332; MHNG: CASENT0404277; MCZ: CASENT0404278; NHMB: CASENT0404289 ).

Diagnosis

Tetramorium vony can be clearly distinguished within the T. bonibony group by the following character combination: mesosoma with well developed anterior face of pronotum but without anterodorsal median protuberance; petiolar node in profile triangular cuneiform, dorsally strongly anteroposteriorly compressed, and highly transverse in dorsal view (LPeI 31–41; DPeI 245–333); postpetiole as wide as to weakly wider than petiolar node (PPI 100–107); body of uniform yellow colour.

Description

HL 0.67–0.80 (0.73); HW 0.65–0.79 (0.72); SL 0.46–0.56 (0.50); EL 0.14–0.18 (0.16); PH 0.41–0.48 (0.44); PW 0.49–0.61 (0.54); WL 0.85–0.98 (0.92); PSL 0.23–0.33 (0.28); PTL 0.09–0.11 (0.10); PTH 0.27–0.33 (0.30); PTW 0.27–0.34 (0.30); PPL 0.21–0.25 (0.22); PPH 0.28–0.35 (0.31); PPW 0.28–0.34 (0.31); CI 96–99 (98); SI 68–72 (70); OI 22–24 (22); DMI 56–62 (58); LMI 46–49 (48); PSLI 33–42 (38); PeNI 53–59 (56); LPeI 31–41 (34); DPeI 245–333 (298); PpNI 55–59 (57); LPpI 69–77 (72); DPpI 133–143 (138); PPI 100–107 (102) (12 measured).

Head usually slightly longer than wide (CI 96–99). Anterior clypeal margin with median impression. Frontal carinae weakly to moderately developed, fading out between posterior eye margin and posterior head margin. Antennal scrobes absent. Antennal scapes short, not reaching posterior head margin (SI 68–72). Eyes of moderate size (OI 22–24). Mesosoma with well developed anterior face of pronotum, but without any anterodorsal median protuberance, mesosoma weakly marginate from lateral to dorsal mesosoma; promesonotal suture and metanotal groove absent, mesosoma comparatively high, compact, and stout (LMI 46–49). Propodeal spines long to very long, spinose, and acute (PSLI 33–42); propodeal lobes small and triangular. Petiolar node in profile triangular cuneiform, strongly anteroposteriorly compressed dorsally, approximately 2.4 to 3.3 times higher than long (LPeI 31–41), anterior and posterior faces not parallel; node in dorsal view highly transverse, between 2.4 to 3.3 times wider than long (DPeI 245–333). Postpetiole in profile approximately rounded and weakly anteroposteriorly compressed, approximately 1.3 to 1.5 times higher than long (LPpI 69–77), in dorsal view between 1.3 to 1.5 times wider than long (DPpI 133–143). Postpetiole in profile appearing slightly more voluminous than petiolar node, in dorsal view approximately as wide as to weakly wider than petiolar node (PPI 100–107). Mandibles striate; clypeus with one distinct median longitudinal ruga and one or two often weaker rugae at each side; cephalic dorsum between frontal carinae anteriorly and centrally longitudinally rugose and posteriorly reticulate-rugose, dorsum with five to nine longitudinal rugae, rugae ending close to posterior head margin but often broken or with crossmeshes, always with one well-developed longitudinal median ruga, median ruga running from posterior head margin to posterior clypeal margin, approximately at eye level diverging into two rugae leading to posterior clypeal margin; lateral and ventral head mainly reticulate-rugose to longitudinally rugose. Ground sculpture on head weakly to moderately reticulate-punctate. Mesosoma laterally reticulate-rugose to irregularly longitudinally rugose, anteriorly often weakly sculptured; dorsal mesosoma mainly reticulate-rugose. Waist segments and gaster unsculptured, smooth, and shiny. All dorsal surfaces of body with abundant, moderately long, fine, and erect pilosity. Body of uniform yellow to light brown colour.

Notes

The distribution of T. vony is mainly restricted to the north of Madagascar. There it occurs from Andavakoera, Antsahabe, and Bekaraoka north to Montagne des Français. However, a single specimen from the botanical garden at the Andasibe National Park was confidently identified as T. vony , although no other conspecific material is known between Andasibe and the northern localities mentioned above. Since T. vony was predominantly sampled from lower vegetation, it is possible that the specimen from the botanical garden was transported with plant material from the main distribution of the species in the north. Furthermore, T. vony is mainly found in tropical dry forests and only very rarely in tropical rainforests. Also, it has an altitudinal range from 60 to 1025 m, but appears to prefer lower elevations.

Due to the lack of an anterodorsal median protuberance on its pronotum T. vony cannot be confused with the three species having a distinct protuberance, T. bonibony , T. popell , and T. trafo . Also, it should not be mistaken for T. kali since this species lacks a well-developed anterior face of the pronotum and has a less transverse petiolar node in dorsal view (DPeI 136–160) while T. vony possesses a very well developed anterior face of the pronotum and a much more transverse petiolar node in dorsal view (DPeI 245–333). Tetramorium nosybe (dark brown) and T. sada (dark brown and yellow) are both differently coloured than T. vony , and thus not likely to be confused. It should be noted, however, that apart from the colour there is little morphological dissimilarity between T. vony and T. nosybe . Nonetheless, T. vony is predominantly found in tropical dry forests, whereas T. nosybe lives in rainforests. The differences in colouration, in combination with the differences in habitat types, provides sufficient evidence to treat them as different species for the moment. Nevertheless, it has to be mentioned that T. vony , T. sada , and T. nosybe do not occur in sympatry. Tetramorium vony is mainly found in the northern tip of Madagascar, whereas T. nosybe is known only in the area around Nosy Be, and T. sada is restricted to western Madagascar. Therefore, it is possible that these three species represent geographic varieties or different ecotypes of the same species.

The remaining species of the group, T. olana , is morphologically very close to T. vony since both are of yellow to light brown colour, share a similar general habitus, and have close morphometric ranges. The main morphological difference is the shape of the petiolar node. In T. olana it is cuneiform and weakly anteroposteriorly compressed in profile and less transverse in dorsal view (LPeI 45–50; DPeI 183–200), whereas it is triangular cuneiform, strongly anteroposteriorly compressed and less transverse in T. vony (LPeI 31–41; DPeI 245–333, generally around 300). The postpetiole is also somewhat differently shaped since it is more anteroposteriorly compressed in T. vony (LPpI 69–77; DPpI 133–143) versus more rounded in T. olana (LPpI 77–88; DPpI 111– 124). Additionally, both species co-occur in one locality (Andavakoera), and retain their specific characteristics, which supports their heterospecificity. Furthermore, both species also differ in their habitat preferences because T. vony lives mainly in tropical dry forests, whereas T. olana seems to be a rainforest inhabitant.

Etymology

The name of the new species is Malagasy and means "yellow". The epithet is treated as a noun in apposition, and thus invariant.

Material examined

MADAGASCAR: Antsiranana, Forêt d'Ampondrabe, 26.3 km 10° NNE Daraina, 12.97 S, 49.7 E, 175 m, tropical dry forest, 11.XII.2003 (B.L. Fisher); Antsiranana, Forêt d' Andavakoera, 21.4 km 75° ENE Ambilobe, 4.6 km 356° N Betsiaka, 13.11833 S, 49.23 E, 425 m, rainforest, 16.XII.2003 (B.L. Fisher); Antsiranana, Forêt d' Antsahabe, 11.4 km 275° W Daraina, 13.21167 S, 49.55667 E, 550 m, tropical dry forest, 13.XII.2003 (B.L. Fisher); Antsiranana, Forêt de Bekaraoka, 6.8 km 60° ENE Daraina, 13.16667 S, 49.71 E, 150 m, tropical dry forest, 7.–8.XII.2003 (B.L. Fisher); Antsiranana, Montagne des Français, 7.2 km 142° SE Antsiranana (=Diego Suarez), 12.32278 S, 49.33817 E, 180 m, tropical dry forest, 22.–28.II.2001 (B.L. Fisher, C. Griswold et al.); Antsiranana, Parc National Montagne d'Ambre [first campsite], 12.51444 S, 49.18139 E, 960 m, rainforest, 4.– 19.III.2001 (R. Harin'Hala); Antsiranana, Rés. Analamerana, 16.7 km 123° Anivorano-Nord, 12.80467 S, 49.37383 E, 225 m, tropical dry forest, 3.–4.XII.2004 (B.L. Fisher); Antsiranana, Rés. Analamerana, 28.4 km 99° Anivorano-Nord, 12.74667 S, 49.49483 E, 60 m, tropical dry forest, 5.–6.XII.2004 (B.L. Fisher); Antsiranana, Réserve Spéciale d'Ambre, 3.5 km 235° SW Sakaramy, 12.46889 S, 49.24217 E, 325 m, tropical dry forest, 26.– 31.I.2001 (B.L. Fisher, C. Griswold et al.); Antsiranana, Rés. Ankarana, 7 km SE Matsaborimanga, 12° 54' S, 49° 07' E, 150 m, rainforest, 30.XI.1990 (P.S. Ward); Antsiranana, Réserve Spéciale de l'Ankarana, 22.9 km 224° SW Anivorano Nord, 12.90889 S, 49.10983 E, 80 m, tropical dry forest, 10.–16.II.2001 (B.L. Fisher, C. Griswold et al.); Antsiranana, Réserve Spéciale de l'Ankarana, 13.6 km 192° SSW Anivorano Nord, 12.86361 S, 49.22583 E, 210 m, tropical dry forest, 16.–21.II.2001 (B.L. Fisher, C. Griswold et al.); Antsiranana, Réserve Spéciale de l'Ankarana, 13.6 km 192° SSW Anivorano Nord, 12.86361 S, 49.22583 E, 210 m, tropical dry forest, 19.– 20.II.2001 (G.D. Alpert); Toamasina, Andasibe National Park, botanic garden near entrance, 18.92639 S, 48.40783 E, 1025 m, tropical forest, 4.–18.VI.2001 (M.E. Irwin & R. Harin'Hala).