Tetramorium malabarense

The type was collected on the grounds of Calicut University Campus.

Identification
A member of the Tetramorium scabrosum-species group.

Sheela and Narendran (1998) - This species comes between Tetramorium rugigaster and Tetramorium transversarium. It differs from rugigaster in that (1) anterolateral angles of gaster angular but not produced into tubercles or teeth (in regigaster anterolateral angles of gaster produced into fine tubercles) (2) first gastral tergite and sternite entirely finely reticulate (in rugigaster only basal half of first tergite and sternite regulose). The species differs from T. transversarium in that (1) petiole node normal (petiole node enormously developed in transversarium (2) dorsum of first gastral tergite finely reticulate (basal l/3 of first gastral tergite feebly rugulose and with traces of superficial punctation in transversarium).

Distribution based on Regional Taxon Lists
Oriental Region: India.

Nomenclature

 *  malabarense. Tetramorium malabarensis Sheela & Narendran, 1998a: 40, figs. 8-12 (w.) INDIA.

Worker
Holotype. Head deeply rugose-reticulate; occipital margin broadly emarginate, mandibles finely striate, masticatory margin broad with three distinct, acute apical teeth and three or four inconspicuous irregular, small denticles towards base; clypeus sub-triangular, anterior margin entire, almost transverse with a flange in front; posterior margin of clypeus arched, three distinct longitudinal carinae on mid lobe of clypeus; frontal area depressed, frontal lobes short, wide apart, frontal carinae extending beyond eyes; scrobe distinctly defined by sculpture within it. Antennae 12-jointed, scape slender, all flagellar segments except first one and club transverse, club 3-jointed, longer than remaining flagellar segments together (14:10); terminal club segment longer than preceding two together (8:6); eyes small, placed laterally on midline of head touching ventral margin of scrobe, elongately oval.

Thorax: Deeply sculptured like head, but median portion of propodeum smooth; evenly convex above, sides not margined, broad anteriorly, narrowing posteriorly; sutures absent; propodeal spines thick stout, acute at apex, prismatic, its length: distance between bases 8:6; in profile spine length 2.6x its basal width; spine let1gth in profile 2.16x length of anterior peduncle of petiole; metasternal teeth triangular, acute at apex, legs smooth short, thick, tibiae and tarsi with a few very long erect hairs, length of some of those hairs on tarsi almost equal to length of basitarsus; on tibiae-length of tibiae 2.5x length of hairs on it.

Abdomen: except anterior peduncle deeply sculptured like head and thorax, anterior peduncle smooth short; nodes subequal in length, length of petiole 2.3x length of peduncle; petiole broader than postpetiole but not as broad as pronotum; height of petiole equal to its length, height of postpetiole more than its length. Gaster biconvex first tergite and sternite finely, longitudinally reticulate, remaining segments shagreened apically, first tergite covering more than 3/4 its total length, anterolateral angles of gaster almost angular but not projecting forward as tubercles or teeth; lamelliform, appendage triangular, projecting at an angle from shaft.

Colour deep reddish brown, legs yellow, mandibles reddish yellow with masticatory margin black, antennae and legs reddish yellow, nodes of pedicel and gaster a little darker than head and thorax. Entire specimen covered with long, thin, erect, pale yellow hairs.

Total length- 3.12mm; Head length- 0. 74mm; Head width- 0.74mm; Cephalic index- l 00; Eye diameter- 0.15mm; Scape length- 0.34mm; Scape index - 46; Pronotal width- 0.59mm; Alitrunk length- 0.89mm.

Type Material
Holotype: Worker. India : Kerala, Calicut University Campus, Sheela S, 10.12.1991 (Department of Zoology, University of Calicut).

Etymology
The species name malabarensis indicate its type locality.

References based on Global Ant Biodiversity Informatics

 * Sheela S.; T.C. Narendran. 1998. On five new species of Tetramorium (Hymenoptera: Formicidae: Myrmicinae) from India. Entomon 23: 37-44.