Tetramorium bonibony 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 : 34-36

Tetramorium bonibony Hita Garcia & Fisher sp. n.

(figs 32, 45, 46, 47)

Holotype worker, MADAGASCAR, Mahajanga, Forêt de Tsimembo, 11.0 km 346° NNW Soatana, 18.99528 S, 44.4435 E, 50 m, tropical dry forest, sifted litter (leaf mold, rotten wood), collection code BLF4508, 21.– 25.XI.2001 (B.L. Fisher, C. Griswold et al.) ( CASC: CASENT0486252 ) . Paratypes, eight workers with same data as holotype ( CASC: CASENT0486219 ; CASENT0486227; CASENT0486254; CASENT0486260; CASENT0486292; CASENT0486294; CASENT0486305; CASENT0486316) ; 12 workers from MADAGASCAR, Mahajanga, Forêt de Tsimembo , 8.7 km 336° NNW Soatana, 19.02139 S, 44.44067 E, 20 m, tropical dry forest, ex rotten log, collection code BLF4573, 21.–25.XI.2001 (B.L. Fisher, C. Griswold et al.) ( BMNH: CASENT0442016 ; CASC: CASENT0442008 ; CASENT0442010; CASENT0442011; CASENT0442013; CASENT0442014; CASENT0442017; CASENT0442018; CASENT0442019; MCZ: CASENT0442009 ; MHNG: CASENT0442012 ; NHMB: CASENT0442015 ) .

Diagnosis

The following character combination distinguishes T. bonibony from the other group members: mesosoma with well-developed anterior face and anterodorsal median protuberance on pronotum; petiolar node triangular cuneiform, strongly anteroposteriorly compressed dorsally, and highly transverse in dorsal view (LPeI 24–27; DPeI 364–414); postpetiole as wide as to weakly wider than petiolar node (PPI 100–106); distinctly bicoloured with brown head and mesosoma and yellow waist segments and gaster.

Description

HL 0.66–0.72 (0.69); HW 0.65–0.71 (0.69); SL 0.48–0.51 (0.49); EL 0.14–0.16 (0.15); PH 0.40–0.45 (0.43); PW 0.49–0.54 (0.51); WL 0.84–0.93 (0.89); PSL 0.25–0.31 (0.28); PTL 0.07–0.09 (0.07); PTH 0.26–0.33 (0.29); PTW 0.26–0.31 (0.29); PPL 0.17–0.21 (0.19); PPH 0.26–0.32 (0.29); PPW 0.27–0.32 (0.29); CI 98–100 (99); SI 69–74 (72); OI 21–22 (21); DMI 57–60 (58); LMI 48–49 (48); PSLI 37–44 (40); PeNI 50–60 (55); LPeI 24–27 (26); DPeI 364–414 (384); PpNI 53–60 (56); LPpI 63–69 (67); DPpI 142–156 (150); PPI 100–106 (101) (10 measured).

Head slightly longer than wide to as long as wide (CI 98–100). Anterior clypeal margin with median impression. Frontal carinae well-developed, ending between posterior eye margin and posterior head margin, usually closer to the latter. Antennal scrobes absent. Antennal scapes short, not reaching posterior head margin (SI 69–74). Eyes comparatively small to moderate (OI 21–22). Pronotum with well-developed anterior face and distinct anterodorsal protuberance, mesosoma moderately marginate from sides to dorsum; promesonotal suture and metanotal groove absent; mesosoma very high, compact, and stout (LMI 48–49). Propodeal spines very long, spinose, and acute (PSLI 37–44); propodeal lobes small and triangular. Petiolar node in profile triangular cuneiform, strongly anteroposteriorly compressed dorsally, approximately 3.6 to 4.2 times higher than long (LPeI 24–27), anterior and posterior faces not parallel; node in dorsal view strongly transverse and thin, between 3.6 to 4.2 times wider than long (DPeI 364–414). Postpetiole in profile approximately rounded, approximately 1.4 to 1.6 times higher than long (LPpI 63–69), in dorsal view approximately 1.4 to 1.6 times wider than long (DPpI 142– 156). Postpetiole in profile more voluminous than petiolar node, in dorsal view as wide as petiolar node or weakly wider (PPI 100–106). Mandibles striate; clypeus with one distinct median longitudinal ruga and one or two weaker rugae at each side; cephalic dorsum between frontal carinae anteriorly and centrally longitudinally rugose, posteriorly reticulate-rugose, dorsum with six to nine longitudinal rugae, rugae ending close to posterior head margin but often broken or with cross-meshes, 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 mostly reticulaterugose to irregularly longitudinally rugose; dorsal mesosoma completely reticulate-rugose. Waist segments and gaster unsculptured, smooth, and shiny. All dorsal surfaces of body with abundant, moderately long, fine, and erect pilosity. Body bicoloured, head and mesosoma brown to dark brown, waist segments and gaster yellow, appendages usually brown.

Notes

Tetramorium bonibony is mainly distributed in western Madagascar in a strip close to the coast from Kirindy north to Anabohazo. All of these localities are situated at very low elevations from 20 to 140 m. It was also found southwest of this main distribution in the Makay Mts., where it was sampled at altitudes of 475 to 525 m. The species was found to live predominantly in tropical dry forests or gallery forests, and mainly collected from the leaf litter.

Tetramorium bonibony can be easily distinguished within the group. The presence of a distinct median protuberance on the anterodorsal pronotum places it close to T. popell and T. trafo . However, T. popell and T. trafo are both of uniform yellowish to brownish colour, whereas T. bonibony is noticeably bicoloured. Tetramorium sada is also bicoloured, and could be confused with T. bonibony at first glance. Closer examination, however, shows that T. sada lacks the anterodorsal pronotal protuberance which is present and well developed in T. bonibony . In addition, the latter species usually has longer antennal scapes (SI 69–74) than T. sada (SI 65–70), and the postpetiole is narrower than the petiolar node in dorsal view (PPI 89–95), in contrast to a postpetiole which is as wide as to wider than the petiolar node (PPI 100–106) in T. bonibony . Both species have strongly overlapping distribution ranges, and occur in sympatry in several localities, such as Bemarivo and Namoroka. Nevertheless, in these localities they can be recognised by the characters outlined above, and we are very confident about their respective species identities.

Etymology

The species epithet is Malagasy and means "bump". It refers to the distinct and conspicuous protuberance on the anterodorsal pronotum. The species name is a noun in apposition and thus invariant.

Material examined

MADAGASCAR: Antsiranana, Forêt d'Anabohazo, 21.6 km 247° WSW Maromandia, 14.30889 S, 47.91433 E, 120 m, tropical dry forest, 11.–16.III.2001 (B.L. Fisher, C. Griswold et al.); Mahajanga, Forêt de Tsimembo, 11.0 km 346° NNW Soatana, 18.99528 S, 44.4435 E, 50 m, tropical dry forest, 21.–25.XI.2001 (B.L. Fisher, C. Griswold et al.); Mahajanga, Forêt de Tsimembo, 8.7 km 336° NNW Soatana, 19.02139 S, 44.44067 E, 20 m, tropical dry forest, 21.–25.XI.2001 (B.L. Fisher, C. Griswold et al.); Mahajanga, Parc National de Namoroka, 9.8 km 300° WNW Vilanandro, 16.46667 S, 45.35 E, 140 m, tropical dry forest, 4.–8.XI.2001 (B.L. Fisher, C. Griswold et al.); Mahajanga, Parc National de Namoroka, 17.8 km 329° WNW Vilanandro, 16.37667 S, 45.32667 E, 100 m, tropical dry forest, 8.–12.XI.2001 (B.L. Fisher, C. Griswold et al.); Mahajanga, Parc National de Namoroka, 16.9 km 317° NW Vilanandro, 16.40667 S, 45.31 E, 100 m, tropical dry forest, 12.–16.XI.2001 (B.L. Fisher, C. Griswold et al.); Mahajanga, Réserve Spéciale de Bemarivo, 23.8 km 223° SW Besalampy, 16.925 S, 44.36833 E, 30 m, tropical dry forest, 19.–23.XI.2001 (B.L. Fisher, C. Griswold et al.); Toliara, Forêt de Kirindy, 15.5 km 64° ENE Marofandilia, 20.045 S, 44.66222 E, 100 m, tropical dry forest, 28.XI.–3.XII.2001 (B.L. Fisher, C. Griswold et al.); Toliara, Kirindy, 47.3 km NE Morondava, 20.07125 S, 44.6655 E, 60 m, tropical dry forest, 7.VI.2007 (B.L. Fisher); Toliara, Makay Mts., 21.2098 S, 45.3418 E, 525 m, gallery forest, 27.XI.–2.XII.2010 (B.L. Fisher et al.).