Tetramorium trafo 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 : 50-52

Tetramorium trafo Hita Garcia & Fisher sp. n.

(figs 33, 35, 63, 64, 65)

Holotype worker, MADAGASCAR, Antsiranana, Forêt d'Orangea , 3.6 km 128° SE Remena, 12.25889 S, 49.37467 E, 90 m, littoral rainforest, sifted litter (leaf mold, rotten wood), collection code BLF3200, 22.– 28.II.2001 (B.L. Fisher, C. Griswold et al.) ( CASC: CASENT0404115 ) . Paratypes, 32 workers with same data as holotype ( BMNH: CASENT0404104 ; CASENT0404114; CASC: CASENT0404103; CASENT0404107; CASENT0404108; CASENT0404109; CASENT0404111; CASENT0404112; CASENT0404113; CASENT0404116; CASENT0404117; CASENT0404118; CASENT0404122; CASENT0404124; CASENT0404125; CASENT0404126; CASENT0404127; CASENT0404128; CASENT0404129; CASENT0404130; CASENT0404131; CASENT0404132; CASENT0404133; CASENT0404137; CASENT0404138; CASENT0404139; CASENT0404140; CASENT0404141; CASENT0404146; MCZ: CASENT0404102; MHNG: CASENT0404134 ; NHMB: CASENT0404136 ).

Diagnosis

Tetramorium trafo is recognisable within the species group due to the character combination of: mesosoma with well-developed anterior face and distinct anterodorsal protuberance or bump on pronotum; petiolar node cuneiform and only weakly anteroposteriorly compressed dorsally (LPeI 48–54; DPeI 161–188); body of uniformly yellowish to brownish colour.

Description

HL 0.57–0.64 (0.61); HW 0.54–0.62 (0.58); SL 0.36–0.41 (0.39); EL 0.13–0.15 (0.14); PH 0.35–0.40 (0.37); PW 0.41–0.45 (0.43); WL 0.68–0.79 (0.74); PSL 0.15–0.18 (0.17); PTL 0.11–0.14 (0.13); PTH 0.23–0.28 (0.26); PTW 0.19–0.25 (0.23); PPL 0.16–0.20 (0.18); PPH 0.23–0.28 (0.25); PPW 0.24–0.29 (0.27); CI 94–97 (95); SI 65–67 (66); OI 24–25 (24); DMI 56–60 (58); LMI 49–51 (50); PSLI 26–29 (27); PeNI 46–57 (53); LPeI 48–54 (51); DPeI 161–188 (175); PpNI 59–66 (63); LPpI 70–75 (73); DPpI 145–156 (149); PPI 116–126 (119) (11 measured).

Head longer than wide (CI 94–97). Anterior clypeal margin medially impressed. Frontal carinae moderately developed, ending between posterior eye margin and posterior head margin. Antennal scrobes absent. Antennal scapes short, not reaching posterior head margin (SI 65–67). Eyes medium-sized to comparatively large (OI 24– 25). Mesosoma with very well developed anterior face and distinct anterodorsal protuberance or bump on pronotum, mesosoma moderately marginate from lateral to dorsal mesosoma; promesonotal suture and metanotal groove absent; mesosoma very high, compact, and stout (LMI 49–51). Propodeal spines medium-sized to long, elongate-triangular to spinose, and acute (PSLI 26–29); propodeal lobes small and triangular. Petiolar node in profile cuneiform, weakly anteroposteriorly compressed dorsally, approximately 1.8 to 2.1 times higher than long (LPeI 48–54), anterior and posterior faces not parallel, anterodorsal margin situated weakly higher than posterodorsal, dorsum moderately tapering backwards posteriorly; node in dorsal view between 1.6 to 1.9 times wider than long (DPeI 161–188). Postpetiole in profile approximately rounded, approximately 1.3 to 1.4 times higher than long (LPpI 70–75), in dorsal view approximately 1.4 to 1.6 times wider than long (DPpI 145–156). Postpetiole in profile approximately as voluminous as petiolar node, in dorsal view approximately 1.1 to 1.3 times wider than petiolar node (PPI 116–126). Mandibles striate; clypeus with one distinct median ruga and one or two weaker and often shorter rugae or rugulae laterally; cephalic dorsum between frontal carinae with five to nine longitudinal rugae anteriorly and dorsally, posteriorly distinctly reticulate-rugose, rugae ending at 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 faint to absent. Mesosoma laterally mostly irregularly longitudinally rugose, with unsculptured areas; dorsal mesosoma anteriorly strongly reticulate-rugose, posteriorly reticulate-rugose to longitudinally rugose. Waist segments usually weakly, superficially sculptured, appearing rough, sometimes almost unsculptured. Gaster unsculptured, smooth, and shiny. All dorsal surfaces of body with very abundant, moderately long, fine, and erect pilosity. Body of uniform yellow to light brown colour.

Notes

Tetramorium trafo is only found at a coastal strip at the eastern side of the northern tip of Madagascar. It ranges from the southernmost locality of Analabe to the northernmost, Ampombofofo. The species seems to prefer littoral rainforests or tropical dry forests in close proximity to the coast, located at low elevations of 10 to 180 m. In addition, T. trafo appears to be a leaf litter inhabitant.

Due to its distinct anterodorsal mesosomal protuberance, T. trafo cannot be misidentified with T. vony , T. kali , T. sada , T. nosybe , and T. olana since they all lack the mesosomal protuberance. In the remaining two species, T. bonibony and T. popell , the protuberance is present and well developed. However, T. bonibony is distinctly bicoloured, while T. trafo is uniformly yellow to brown. Finally, the distinction from T. popell is based on petiolar node shape and sculpture. Tetramorium trafo has a cuneiform petiolar node with a much less anteroposteriorly compressed dorsum than T. popell . Also, the node of the latter is always completely unsculptured, smooth, and shiny, whereas the node of T. trafo is weakly sculptured and appears moderately rough.

Etymology

The species epithet is Malagasy and means "the hump of cattle" in reference to the anterodorsal protuberance or hump on the anterior mesosoma of the new species. The species name is a noun in apposition, and thus invariant.

Material examined

MADAGASCAR: Antsiranana, Forêt d'Ampombofofo, 12.09949 S, 49.33874 E, 25 m, littoral forest, 21.– 22.XI.2007 (B.L. Fisher et al.); Antsiranana, Forêt d'Ampondrabe, 26.3 km 10° NNE Daraina, 12.97 S, 49.7 E, 175 m, tropical dry forest, 10.XII.2003 (B.L. Fisher); Antsiranana, Forêt d'Analabe, 30.0 km 72° ENE Daraina, 13.08333 S, 49.90833 E, 30 m, littoral rainforest, 27.–29.XI.2003 (B.L. Fisher); Antsiranana, Forêt d'Orangea, 3.6 km 128° SE Remena, 12.25889 S, 49.37467 E, 90 m, littoral rainforest, 22.–28.II.2001 (B.L. Fisher, C. Griswold et al.); Antsiranana, Montagne des Français, 12.32033 S, 49.3365 E, 180 m, 31.XII.2005 (A. Ballerio); 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, Rés. Analamerana, 28.4 km 99° Anivorano-Nord, 12.74667 S, 49.49483 E, 60 m, tropical dry forest, 5.XII.2004 (B.L. Fisher); Antsiranana, Sakalava Beach [vegetated beach dunes], 12.26278 S, 49.3975 E, 10 m, across sandy trail in dwarf littoral forest, 31.V.–7.VI.2001 (R. Harin'Hala).