Tetramorium kelleri Forel,

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 : 11-12

Tetramorium kelleri Forel, 1887

(Figs. 3, 4, 8, 9, 10, 141)

Tetramorium (Xiphomyrmex) kelleri Forel, 1887:385. Syntype workers, MADAGASCAR, Toamasina, Ivondro, pr. Tamatave (C. Keller). (BMNH: CASENT0102339; NHMB: CASENT0101138; MCZ: CASENT0247309; CASENT0247310; MHNG: CASENT0101293; CASENT0101294; CASENT0101938; USNM) [all examined, except material from USNM].

Diagnosis

Tetramorium kelleri differs from T. ankarana by the character combination of: large eyes (OI 24-26); relatively shorter antennal scapes (SI 89-99); and extremely long propodeal spines (PSLI 49-68).

Description

HL 0.98-1.11 (1.03); HW 0.85-0.97 (0.90); SL 0.79-0.90 (0.85); EL 0.21-0.24 (0.22); PH 0.45-0.58 (0.52); PW 0.66-0.80 (0.73); WL 1.29-1.48 (1.37); PSL 0.50-0.73 (0.59); PTL 0.36-0.44 (0.40); PTH 0.37-0.44 (0.40); PTW 0.29-0.36 (0.33); PPL 0.32-0.37 (0.34); PPH 0.38-0.44 (0.40); PPW 0.37-0.43 (0.40); CI 84-89 (87); SI 89-99 (94); OI 24-26 (25); DMI 50-59 (53); LMI 35-40 (38); PSLI 49-68 (57); PeNI 41-50 (46); LPeI 95-102 (99); DPeI 79-86 (83); PpNI 49-59 (55); LPpI 81-90 (86); DPpI 109-124 (117); PPI 114-126 (121) (25 measured).

Head much longer than wide (CI 84-89); posterior head margin very weakly concave. Anterior clypeal margin medially impressed, often weakly so. Frontal carinae strongly developed, approaching corners of posterior head margin. Antennal scrobes well-developed, moderately deep, narrow, and without defined posterior margin; ventral margin moderately defined. Antennal scapes moderately long to long, reaching posterior head margin (SI 89-99). Eyes large (OI 24-26). Mesosomal outline in profile flat to weakly convex, very weakly marginate from lateral to dorsal mesosoma, sides rounding smoothly onto the dorsum; promesonotal suture and metanotal groove absent; mesosoma comparatively stout and high (LMI 35-40). Propodeal spines extremely long, spinose and acute (PSLI 49-68); propodeal lobes short, triangular, and rounded, sometimes weakly acute. Petiolar node in profile clublike with fairly rounded margins, ranging from weakly longer than high to weakly higher than long (LPeI 95-102), anterodorsal margin situated lower than posterodorsal margin, dorsum noticeably convex; node in dorsal view approximately 1.2 to 1.3 times longer than wide (DPeI 79-86). Postpetiole in profile globular to subglobular, approximately 1.1 to 1.2 times higher than long (LPpI 81-90); in dorsal view around 1.1 to 1.3 times wider than long (DPpI 109-124). Postpetiole in profile appearing less voluminous than petiolar node, in dorsal view 1.1 to 1.3 times wider than petiolar node (PPI 114-126). Mandibles strongly striate; clypeus longitudinally rugose/rugulose, median ruga always present and distinct, remaining rugae/rugulae weaker and variably developed; cephalic dorsum between frontal carinae reticulate-rugose to longitudinally rugose, posteriorly more reticulate-rugose and anteriorly more longitudinally rugose; lateral and ventral head mostly reticulate-rugose. Mesosoma dorsally mainly reticulate-rugose, laterally reticulate-rugose to longitudinally rugose. Forecoxae usually with weak to moderately developed longitudinal rugae/rugulae, sometimes reduced. Waist segments mainly longitudinally rugulose, less reticulate-rugulose. First gastral tergite unsculptured, smooth, and shining. Whole body covered with numerous, very long, fine standing hairs. Body of uniform whitish-yellowish to brown, mostly yellowish to orange-brown.

Tetramorium kelleri is mainly encountered in northern and western Madagascar, and on several islands including Nosy Be, Nosy Mangabe, and Nosy Ngontsy. Interestingly, most localities are in relatively close proximity to the ocean since no material was collected more than 50 km inland. One aspect that deserves attention, however, is the type locality, the Ivondro River, which is relatively far from the currently known distribution range mentioned above. The area around the Ivondro River in eastern Madagascar was intensively sampled by the Malagasy ant inventory (see Fisher, 2005), but no additional T. kelleri material was found. Indeed, not a single modern specimen is known from eastern Madagascar south of Nosy Mangabe. One possible explanation could be that the species was present in the area over 120 years ago, but did not survive until the present day. This is surprising, though, since the species is comparatively flexible in its habitat requirements. It was collected from rainforest, littoral rainforest, tropical dry forest, and secondary forest at elevations from 5 to 780 m, although mostly at the lower range.

Despite being a very common species with a relatively broad distribution range, which includes several islands, T. kelleri remains remarkably invariable. Some minor variation in colouration is observed ranging from whitish-yellowish to brown, although we do not think it significant for species diagnostics. In general, as already stated by Bolton (1979), it is a highly conspicuous and easily recognisable Malagasy ant species. The only other species it could be confused with is the second species of the T. kelleri group, T. ankarana . The latter species, however, has much smaller eyes (OI 20) and propodeal spines (PSLI 35-38), and slightly longer antennal scapes (SI 101-104) than T. kelleri (OI 24-26; SI 89-99; PSLI 49-68).

Material examined

MADAGASCAR: Antsiranana, Ambondrobe, 41.1 km 175° Vohemar, 13.7153 S, 50.1017 E, 10 m, littoral rainforest, 30.XI.-1.XII.2004 (B.L. Fisher); Antsiranana, Réserve Spéciale d'Ambre, 3.5 km 235° SW Sakaramy, 12.4689 S, 49.2422 E, 325 m, tropical dry forest, 26.-31.I.2001 (B.L. Fisher, C. Griswold et al.); Antsiranana, Ampahana, 18 km N Antalaha, 14° 46' S, 50° 13' E, 1 m, lowland forest, 5.II.1991 (G.D. Alpert); Antsiranana, Forêt d' Andavakoera, 21.4 km 75° ENE Ambilobe, 4.6 km 356° N Betsiaka, 13.1183 S, 49.23 E, 425 m, rainforest, 15.XII.2003 (B.L. Fisher); Antsiranana, 5 km SW Antalaha, 14° 56' 17" S, 50° 15' 42" E, 50 m, secondary forest, 10.II.1991 (G.D. Alpert); Antsiranana, Forêt d' Antsahabe, 11.4 km 275° W Daraina, 13.2117 S, 49.5567 E, 550 m, tropical dry forest, 12.XII.2003-16.XI.2004 (B.L. Fisher); Antsiranana, Forêt de Binara, 7.5 km 230° SW Daraina, 13.255 S, 49.6167 E, 375 m, tropical dry forest, 1.-2.XII.2003 (B.L. Fisher); Antsiranana, 6 km N Cap Est, 5 m, 20.I.1991 (G.D. Alpert); Antsiranana, R.S. Manongarivo, 10.8 km 229° SW Antanambao, 13.9767 S, 48.4233 E, 780 m, rainforest, 11.-17.X.1998 (B.L. Fisher); Antsiranana, R.S. Manongarivo, 10.8 km 229° SW Antanambao, 13.9617 S, 48.4333 E, 400 m, rainforest, 8.-13.XI.1998 (B.L. Fisher); Antsiranana, 2 km NE Marofinaritra, 15° 3' S, 50° 9' E, 50 m, lowland forest, 8.II.1991 (G.D. Alpert); Antsiranana, Nosy Be, 4 km ENE Andoany, (=Helleville), 13° 25' S, 48° 18' E, 200 m, rainforest, 2.V.1989 (P.S. Ward); Antsiranana, Nosy Be, Réserve Naturelle Intégrale de Lokobe, 6.3 km 112° ESE Hellville, 13.4193 S, 48.3312 E, 30 m, rainforest, 19.-24.III.2001 (B.L. Fisher, C. Griswold et al.); Antsiranana, Nosy Ngontsy, 55 km S Antalaha, 15° 15' 51.9" S, 50° 29' 21.5" E, 1m, secondary rainforest, 21.I.1991 (G.D. Alpert); Antsiranana, Sakaramy, 12.4411 S, 49.232 E, 260 m, tropical dry forest, 11.-12.V.2011 (B.L. Fisher et al.); Mahajanga, Réserve Spéciale de Bemarivo, 23.8 km 223° SW Besalampy, 16.925 S, 44.3683 E, 30 m, tropical dry forest, 19.-23.XI.2002 (B.L. Fisher, C. Griswold et al.); Mahajanga, Parc National de Namoroka, 16.9 km 317° NW Vilanandro, 16.4067 S, 45.31 E, 100 m, tropical dry forest, 12.-16.XI.2002 (B.L. Fisher, C. Griswold et al.); Toamasina, Ivondro, pr. Tamatave (C. Keller); Toamasina, Nosy Mangabe, 7.43 km S Maroantsetra, 15.4973 S, 49.7622 E, 5 m, littoral rainforest edge, 26.VII.2007 (B.L. Fisher et al.); MAYOTTE: Mt. Benara, 12.8758 S, 45.1567 E, 425 m, 30.XI.-2.XII.2007 (B.L. Fisher et al.); Mt. Chongui, 12.8 S, 45.1 E, 360 m, forest near fallen tree, 15.II.-3.III.1999 (R. Jocque & G. DeSmet); Mt. Chongui, 12.9578 S, 45.134 E, 470 m, rainforest, 28.XI.2007 (B.L. Fisher et al.); Mt. Chongui, 12.959 S, 45.1341 E, 380 m, rainforest, 28.-30.XI.2007 (B.L. Fisher et al.); Mt. Combani, 12.8 S, 45.1333 E, 470 m, forest litter, 22.-24.II.1999 (R. Jocque & G. DeSmet); Mt. Combani, 12.8063 S, 45.1531 E, 370 m, rainforest, 25.XI.-4.XII.2007 (B.L. Fisher et al.); Mt. Combani, 12.8049 S, 45.1527 E, 460 m, rainforest, 29.XI.2007 (B.L. Fisher et al.); Coconi, DAF Campus, 12.8333 S, 45.1333 E, 15.I.1999 (R. Jocque & G. DeSmet); Dapani, 12.9628 S, 45.1504 E, 135 m, rainforest, 2.-4.XII.2007 (B.L. Fisher et al.); Reserve Forestiére Majimbini , 12.768 S, 45.1861 E, 525 m, rainforest, 3.XII.2007 (B.L. Fisher et al.); Reserve Forestiére Majimbini , 12.7689 S, 45.1902 E, 350 m, rainforest, 3.XII.2007 (B.L. Fisher et al.); Tsingoni, 12.7833 S, 45.1 E, litter of shrubs on mangrove edge, 27.II.-4.III.1999 (R. Jocque & G. DeSmet).