Discothyrea sringerensis, Zacharias, M. & Rajan, P. D., 2004

Zacharias, M. & Rajan, P. D., 2004, Discothyrea sringerensis (Hymenoptera: Formicidae) a new ant species from India., Zootaxa 484, pp. 1-4 : 2-3

Discothyrea sringerensis sp. nov.

Description of holotype. Worker (Fig. 1). Total body length 3.05mm, Head length 0.80mm, Head width 0.54mm, Cephalic Index (HW/HL x 100) 67, scape length 0.46mm, petiole height 0.25mm, dorsal petiole length 0.10mm, dorsal petiole width 0.28mm.

Head from front broadly oval with almost straight posterior margin. Clypeus extending forward so that it overhangs the rear part of the mandibles when they are closed. Anterior margin of the clypeus crenulated. Palp formula 5, 4. Antennae 10 segmented; scape massively clavate. Second antennal segment 0.06mm long, sub globular. 3rd to 6th antennal segments almost equal in length (each 0.07mm). 7th-9th antennal segments distinctly wider than long. Apical antennal segment large, twice as long as wide (Fig. 2). Depressed scrobal area distinct. Frontal carinae extending back about two-thirds the length of the head, dilated and horizontally flattened in the middle. Posterior end of frontal lobe opened and rounded anteroposteriorly and continuous with the regular convex surface of the head. Eyes placed on side of head nearer to the base of the mandibles than to the posterior border of the head, composed of at least 12 ommatidia in each with hairs in between the ommatidia.

Mesosoma stout, with blunt, rounded humeral angles. Propodeum with more distinct propodeal teeth. Legs stout, spur of posterior leg pectinate, spur on middle leg absent.

Petiole in the form of a thick disc, 2.80 times broader than long dorsally and with two low rims running along the anterior and posterior margins of the petiole. The petiole is attached over a large portion of its posterior surface to the gaster and is lower in height than the gaster. In profile, petiole with weakly concave dorsal margin and a sloping anterior surface. Subpetiolar process on the ventral margin, a prominent compressed translucent tooth.

Head, mesosoma and abdomen coarsely punctate. The scrobal depressions sparsely punctate with horizontal striations that extend from the lateral walls of the frontal lobe. The entire body densely clothed with short suberect to erect whitish pubescence, which is slightly shorter on the head and antennae.

Body colour reddish brown with mandibles, antennae, legs and tip of gaster yellowish brown.

Holotype. Worker, India, Karnataka, Kumbarakodu Reserve Forest of Sringeri (13°29'19'' N and 75°11'52'' E). 26. iii. 2001. P.A. Sinu. Collected from evergreen forest leaf litter using pitfall trap.

Paratypes. 6 workers, data same as holotype.

Type repository. Holotype will be deposited at the Museum of the Zoological Survey of India, Calcutta and the paratypes will be deposited at the British Museum of Natural History and Insect Museum of Ashoka Trust for Research in Ecology and the Environment (ATREE), Bangalore, Karnataka, India.

Etymology. The species name sringerensis indicates its type locality.

Remarks

This species is similar to one Malaysian species, Discothyrea bryanti Wheeler , and one Australian species, Discothyrea velutina , in the following characteristics: (1) Antennae with 10 segments, and (2) absence of spur in middle tibiae. Discothyrea sringerensis is similar to D. bryanti in the following characters: (1) petiole with a prominent compressed translucent tooth on its ventral surface, and (2) more distinct propodeal teeth. However, the Indian species differs from D. bryanti in (1) the funiculus being distinctly longer than the antennal scape (Fig. 2), (2) the petiole being less than four times as broad as long, and (3) the cheeks without a prominent blunt tooth in front of the eyes. Discothyrea sringerensis shows some affinity to D. velutina in the following characters: (1) cheeks without a blunt tooth in front of eyes, and (2) funiculus longer than scape. However, it differs from D. velutina in the following characters: (1) distinct propodeal teeth, (2) petiole with a prominent compressed translucent tooth on its ventral surface, and (3) palp formula 5,4 ( D. velutina has a palp formula of 4,4). The maxillary and labial palps are variously segmented, according to species (Brown 1958). The palp formula of D. bryanti is unavailable.