Cerapachys seema, Bharti, Himender & Akbar, Shahid Ali, 2013

Bharti, Himender & Akbar, Shahid Ali, 2013, Taxonomic studies on the ant genus Cerapachys Smith (Hymenoptera, Formicidae) from India, ZooKeys 336, pp. 79-103 : 94-97

Cerapachys seema sp. n. Figures 8B, 29, 30, 31, 32, 33, 34, 35, 36, 37, 41, Table 1

Type material.

Holotype worker: India. Kerala, Periyar tiger reserve, Manalar, 9°35'N, 77°18'E, 1630m a.s.l., 24.x.2011, hand picking. Paratypes: 4 workers, 3 ergatoid queens and 1 gyne, same data as holotype (coll. Shahid A. Akbar). Holotype in PUAC and paratype in BMNH.

Worker description.

Measurements (holotype in brackets): HL 0.72-0.74 (0.74); HW 0.52-0.56 (0.56); EL 0.07-0.19 (0.19); WL 0.77-0.82 (0.77); MH 0.38-0.45 (0.45); PrW 0.37-0.40 (0.38); PL1 0.23-0.29 (0.26); PW1 0.36-0.41 (0.41); IIIAL 0.41-0.46 (0.41); IIIAW 0.51-0.54 (0.51); SL 0.33-0.41 (0.41); IVAL 0.70-0.74 (0.74); IVAW 0.62-0.69 (0.63). Indices: CI 72-75 (75); SI 63-73 (73); PI 141-157 (157) (n=9).

Head, longer than broad; sides converging posteriorly; vertexal margin transverse. Posterior lateral corners weakly acute. Parafrontal ridges prominent, raised. Eyes small. Mandibles subtriangular; masticatory margins deflexed and downcurved, with a row of small denticles. Lateroclypeal teeth prominent. Antennae 12 segmented; scapes clavate, reaching up to 2/3rd the distance to the posterior margin of head.

Mesosoma moderately stout, rectangular in dorsal view; dorsal surface flattened and gently rounded towards the sides. Declivous face of propodeum with cariniform margins across the top and along its lateral margins.

Metasoma, Petiole broader than long, lacking dorsolateral margins. Anterior and posterior faces transverse. Subpetiolar process well developed, located below the anterior 1/3rd of the petiole; fenestra present. Postpetiole broader than long with posterolateral angles uniformly rounded. Gaster elongate; base of cinctus of first gastral tergite with cross ribs; sting exerted.

Sculpture. Mandibles smooth with few punctures. Head with prominent punctures, spaced more widely than their diameter. Similar sculpture on dorsal surface of mesosoma. Petiole and postpetiole with larger punctures, forming a rugae-like surface on the dorsum. Gaster with similar sculpture to mesosoma. Cinctus of 1st gastral segment with prominent transverse ribs.

Vestiture. Whole body covered with dense decumbent or subdecumbent yellowish hairs, sides of head and mesosoma with fewer hairs; apical funicular segments and legs with standing hairs.

Colour. Dark brownish black with mandibles, antennae and legs castaneous.

Ergatoid queen measurements.

HL 0.73-0.82; HW 0.55-0.60; EL 0.14-0.18; WL 0.81-0.86; PL1 0.27-0.29; MH 0.36-0.41; PrW 0.41-0.44; PW1 0.36-0.39; IIIAL 0.44-0.50; IIIAW 0.51-0.53; SL 0.39-0.42; IVAL 0.75-0.76; IVAW 0.72-0.77. Indices: CI 73-75; SI 70-71; PI 133-134 (n=3).

Like the workers of the same colony, but larger, with a more stout body, especially the mesosoma and gaster. Ocelli present on vertex, prominent. The pilosity is much more prominent when compared with the workers. Distinction between ergatoid queens and workers is vague with size variation of workers very high.

Gyne measurements.

HL 0.77; HW 0.55; EL 0.08; WL 0.93; MH 0.44; PrW 0.41; PL1 0.27; PW1 0.36; IIIAL 0.38; IIIAW 0.49; SL 0.38; IVAL 0.76; IVAW 0.73. Indices: CI 71; SI 69; PI 133 (n=1).

Resembles the worker, with modifications expected for caste and the following differences; three prominent ocelli present on vertex, thicker body with heavy pilosity and prominent sculpture.

Etymology.

The species epithet is Hindi for border, in reference to its type locality, Manalar, a place which marks border between Kerala and Tamil Nadu.

Differential diagnosis.

Thespecies is characterized by the punctures on the dorsum of the head being relatively small, separated, with their diameter smaller than the average distance separating them. The new species sharesmost characters with Cerapachys schoedli . However the two species can be easily separated. Cerapachys seema has dull body colouration, sculpture much more prominent and course, pilosity denser, eyes not breaking the lateral margins of head and head almost oval, with anterior and posterior sections of the sides converging, while Cerapachys schoedli is brightly coloured, its sculpture and pilosity are reduced, its eyes break the lateral margins of the head and the head is rectangular with parallel sides.

Ecology.

Manalar, part of Periyar tiger reserve, the type locality of this species is a fascinating green hill station (with plenty of leaf litter) surrounded on all sides by the tea gardens of Tamil Nadu. This species was found nesting beneath the marker stone on the border which separates Kerala and Tamil Nadu. It is presumed that the nest was in its initial stages of establishment as there were hardly any galleries and underground chambers. A single queen, 3 ergatoid queens and 7 workers were collected. This species seems uncommon in the Western Ghats range, since it was not encountered again from any other locality.