Tetramorium artemis 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 : 12-15

Tetramorium artemis Hita Garcia & Fisher sp. n.

(figs 1, 3, 11, 12, 13)

Holotype worker, MADAGASCAR, Toliara, Réserve Spéciale de Cap Sainte Marie , 14.9 km 261° W Marovato, 25.59444 S, 45.14683 E, 160 m, spiny forest/thicket, sifted litter (leaf mold, rotten wood), BLF5570, 13.– 19.II.2002 (Fisher, B.L. & C. Griswold) ( CASC: CASENT0481732 ) Paratypes, eight workers with same data as holotype ( BMNH: CASENT0481734 ; CASC: CASENT0481723 , CASENT0481729 ; CASENT0481731; CASENT0481750; CASENT0481752; CASENT0481756; MHNG: CASENT0481743 ) .

Diagnosis

The following character combination separates T. artemis from the other species of the group: head approximately as long as wide (CI 99–101); petiolar node squamiform and strongly anteroposteriorly compressed with anterodorsal angle situated higher than posterodorsal, dorsum tapering backwards posteriorly, in dorsal view strongly transverse (DPeI 232–250); and reduced cephalic sculpture between the frontal carinae with just one median longitudinal ruga.

Description

HL 0.67–0.72 (0.69); HW 0.66–0.71 (0.69); SL 0.47–0.51 (0.49); EL 0.14–0.16 (0.15); PH 0.37–0.43 (0.40); PW 0.48–0.52 (0.50); WL 0.82–0.89 (0.86); PSL 0.18–0.20 (0.19); PTL 0.10–0.11 (0.10); PTH 0.27–0.31 (0.29); PTW 0.24–0.26 (0.24); PPL 0.21–0.23 (0.22); PPH 0.27–0.32 (0.29); PPW 0.30–0.32 (0.31); CI 99–101 (100); SI 69–73 (71); OI 20–23 (21); LMI 44–48 (46); DMI 58–61 (59); PSLI 27–29 (28); PeNI 47–50 (48); LPeI 32–38 (35); DPeI 232–250 (240); PpNI 60–63 (62); LPpI 70–79 (75); DPpI 136–143 (140); PPI 122–131 (127) (nine measured).

Head approximately as long as wide (CI 99–101). Anterior clypeal margin with distinct median impression. Frontal carinae well-developed, ending shortly behind level of posterior eye margin. Antennal scrobes faint to absent, posterior and ventral margins never differentiated. Antennal scapes comparatively short, not reaching posterior head margin (SI 69–73). Eyes comparatively small to moderate (OI 20–23). Mesosomal outline in profile convex, dorsum transversely rounded, dorsolateral margin only weakly developed, promesonotal suture and metanotal groove absent; mesosoma comparatively stout and high (LMI 44–48). Propodeal spines elongatetriangular, long, and acute (PSLI 27–29). Propodeal lobes reduced, very small, and bluntly triangular. Petiolar node strongly squamiform and anteroposteriorly compressed, anterior and posterior faces not parallel, anterodorsal margin higher situated and better developed than weaker posterodorsal margin, dorsum tapering backwards posteriorly; node in dorsal view transverse, between 2.3 to 3.5 times wider than long (DPeI 232–250), in lateral view distinctly more than 2.5 times higher than long (LPeI 32–38). Postpetiole in profile rounded and weakly anteroposteriorly compressed, approximately 1.3 to 1.4 times higher than long (LPpI 70–79), in dorsal view approximately 1.3 to 1.4 times wider than long (DPpI 136–143). Postpetiole in profile more voluminous than petiolar node, in dorsal view approximately 1.2 to 1.3 times wider than petiolar node (PPI 122–131). Mandibles distinctly longitudinally striate; clypeus always with strong median longitudinal ruga and one weaker ruga at each side; remainder of head mostly unsculptured, cephalic dorsum between frontal carinae only with one welldeveloped longitudinal median ruga, median ruga diverging approximately at eye level into two rugae running to posterior clypeal margin, remainder unsculptured, median ruga of same length as frontal carinae; head laterally and ventrally mostly unsculptured, anteriorly approximately at malar area irregularly rugose. Head with faint punctate ground sculpture. Mesosoma, waist segments, and gaster unsculptured and smooth, only moderately shining due to faint ground sculpture. Head generally with several fine, long, erect hairs, and more numerous appressed to decumbent widely spaced pubescence; mesosoma usually with one pair of standing hairs on promesonotum and very sparse, short, and inconspicuous pubescence; waist segments and first gastral tergite without any pilosity, only with very short, widely spaced, strongly appressed pubescence. Head, antennae, legs, and gaster of brown colour, mesosoma and waist segments of lighter brown.

Notes

At present, the new species is only known from the type locality, the Cap Saint Marie, where it was sampled from sifted litter in a spiny forest/thicket habitat at an elevation of 160 m.

Within the species group, the identification of Tetramorium artemis is straightforward and comparatively easy. It can be well separated from T. malagasy , T. orientale , and T. ryanphelanae since the latter three all display a high nodiform and much less anteroposteriorly compressed petiolar node in comparison to the squamiform node of T. artemis . The remaining two species, T. bessonii and T. wardi , have approximately the same node shape as T. artemis , but can be easily distinguished from the latter. The head of T. bessonii is distinctly longer than wide (CI 92–96) while the head of T. artemis is approximately as long as wide (99–101). In addition, T. bessonii shows comparatively long appressed to decumbent pubescence on the first gastral tergite, which contrasts with the very short, strongly appressed pubescence of T. artemis . Tetramorium wardi shares most characters with T. artemis , but differs in cephalic sculpture and petiolar node shape. In T. wardi the cephalic sculpture between the frontal carinae consists of a strong median ruga and several irregular rugae between the median ruga and the frontal carinae. In T. artemis though, only one median ruga is developed between the frontal carinae. Also, the petiolar node of T. wardi (DPeI 267–333) is more compressed and transverse than in T. artemis (DPeI 232–250).

Etymology

This new species is named after the goddess "Artemis" from Old Greek mythology, which was the goddess of the hunt, wilderness, and animals. The name is a noun in apposition, and thus invariant.

Material examined

MADAGASCAR: Toliara, Réserve Spéciale de Cap Sainte Marie, 14.9 km 261° W Marovato, 25.59444 S, 45.14683 E, 160 m, spiny forest/thicket, 13.–19.II.2002 (Fisher, B.L. & C. Griswold).