Cerapachys anokha, 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 : 87-89

Cerapachys anokha sp. n. Figures 7B, 14, 15, 16, Table 1

Type material.

Holotype and 3 paratypes (worker): India: Kerala, Periyar tiger reserve, Thanikkudy, 9°.30'N, 77°.16'E, 1003m a.s.l., 15.x.2011, hand picking method (coll. Shahid A. Akbar). Holotype in PUAC and paratype in BMNH.

Worker description.

Measurements (holotype in brackets): HL 0.69-0.73 (0.72); HW 0.60-0.63 (0.63); EL 0.20-0.22 (0.22); WL 0.72-0.80 (0.80); MH 0.33-0.38 (0.38); PrW 0.42-0.47 (0.47); PL1 0.29-0.33 (0.33); PW1 0.38-0.41 (0.41); IIIAL 0.38-0.45 (0.41); IIIAW 0.44-0.55 (0.52); SL 0.29-0.32 (0.32); IVAL 0.85-0.92 (0.92); IVAW 0.57-0.64 (0.64). Indices: CI 86-87 (87); SI 48-51 (51); PI 124-131 (124) (n=4).

Head. Rectangular, longer than broad, widest at about mid-length; sides parallel; vertexal margin slightly concave, posterior lateral corners are weakly acute to rounded. Parafrontal ridges present. Eyes prominent, placed below midline of head. Mandible triangular with acute apices and sharp concave, edentate, masticatory margins; anterior clypeal margin with small apron shaped transparent structure. Lateroclypeal teeth small, blunt and projecting slightly inwards. Antennae 12 segmented; scape short and clavate, reaching up to 1/3rd of posterior margin of head.

Mesosoma. Stout, rectangular in dorsal view; dorsal surface convex, the dorsal surface gently rounded along sides without any distinct margin. Declivous face of propodeum lacking cariniform margins across the top and along sides.

Metasoma. Petiole highly convex, broader than long, with traces of reduced dorsolateral margins, anterior and posterior faces continuous with dorsum. Subpetiolar process prominent, wedge like, with apex directed backward; no fenestra present. Postpetiole wider than long, uniformly rounded. Gaster elongate; base of cinctus of first gastral tergite with cross ribs; sting exerted.

Sculpture. Mandibles smooth and shining. Head with few small punctures. Sculpture on dorsal surface of mesosoma, petiole and postpetiole consist of very small, uniform punctures, distributed throughout the surface. Gaster mostly smooth, with few scattered punctures. Cinctus of 1st gastral, with few cross ribs.

Vestiture. Body covered with decumbent or subdecumbent hairs. Longer hairs are also present on postpetiole and gaster. Head also consists of few long hairs; apical funicular segments and legs with standing hairs.

Colour. Black with mandibles, antennae and legs castaneous.

Etymology.

The species epithet is Hindi for “unique”, in reference to its unique nature of propodeal declivity.

Differential diagnosis.

This species is unique in having the declivous face of the propodeum lacking cariniform margins across the top and along the sides, features unique in described workers of the Cerapachyinae . The new species show interesting variation in the form of the petiole. The petiolar node has the inferior as well as the superior posterolateral angles produced, but not sharply angular. The sides of the petiole could not be considered either immarginate ( Cerapachys lineage) or marginate ( Phyracaces lineage). This makes the placement of this species somewhat transitional between the two lineages and easily distinguishes it from other reported species of the genus. When using Brown’s (1975) key Cerapachys anokha comes close to singaporensis Viehmeyer, 1916. The two species however can be easily separated. Cerapachys singaporensis has the body arrayed with long pale hairs; and copiously pubescent, and the dorsal sides of the petiole strongly marginate, while Cerapachys anokha has only decumbent or subdecumbent body hairs, little pubescence and the dorsolateral sides of petiole are not marginate. Cerapachys anokha could also be confused with Cerapachys nayana which has similar habitat preferences and body colouration; however the two species can be easily separated: Cerapachys nayana has larger eyes (EL 0.24-0.27 mm), the declivous face of the propodeum has cariniform margins across the top, and the petiole has marginate dorsolateral sides; while Cerapachys anokha has smaller eyes (EL 0.20-0.22 mm), the declivous face of its propodeum lacks cariniform margins across the top, and the petiole is without marginate dorsolateral sides.

Ecology.

This species seems to be infrequent. It is from the Western Ghats. Four specimens were collected by handpicking from the Thanikkudy region of the Periyar tiger reserve. Which is a primary, undisturbed tropical moist evergreen forest. The area is situated at 1003 meters elevation. It is a shady place with little sunlight penetration.