Parastylotermes krishnai Engel & Grimaldi

Engel, Michael S., Grimaldi, David A., Nascimbene, Paul C. & Singh, Hukam, 2011, The termites of Early Eocene Cambay amber, with the earliest record of the Termitidae (Isoptera), ZooKeys 148, pp. 105-123 : 106-107

Parastylotermes krishnai Engel & Grimaldi sp. n. Figs 1B3

Holotype.

Imago (sex unknown); Tad-277 (Fig. 1B), India: Gujarat: Tadkeshwar lignite mine, Cambay Formation (Paleo-Eocene), 21°21.400"N, 73°4.532"E, 17-22 January 2010 (BSIPL).

Additional material.

Imago; Tad-96, India: Gujarat: Tadkeshwar lignite mine, Cambay Formation (Paleo-Eocene), 21°21.400"N, 73°4.532"E, 7-12 January 2009 (AMNH). This specimen is a poorly preserved alate, with much of the specimen crushed and large portions of the upper body, wings, &c. missing. However, the front of the head is not deformed, with a good frontal view of the clypeus (Fig. 3B). The existing wing fragments show a venation very similar to that of the holotype, and the antenna has 14 antennomeres, as in the holotype. These features, along with the trimerous tarsi, strongly suggest that this is an additional individual of this species.

Diagnosis.

The new species can be distinguished from all other Parastylotermes by the apical branching of the medial vein in the forewing (branching in the apical quarter rather than being unbranched or branched only at the extreme wing apex), less reticulation, more CuA branches (10, versus 7-8 in Parastylotermes robustus ) and by the smaller number of antennal articles (14 in the new species, 16-17 in Parastylotermes robustus , unknown for Parastylotermes frazieri , Parastylotermes washingtonensis , and Parastylotermes calico , which are just forewings preserved as compressions). In all other respects, Parastylotermes krishnai matches the description and lectotype (visum) for Parastylotermes robustus in Baltic amber except for in general metrics and some aspects of coloration ( Weidner 1955; Emerson 1971; Engel et al. 2007a).

Description.

Imago: Total length without wings (as preserved) ~4.0 mm; forewing length 5.7 mm, width 1.7 mm; length of forewing scale 0.8 mm; three maxillary and labial palpomeres. Integument finely imbricate throughout; head dark brown with scattered long, erect, light brown setae, short setae exceptionally sparse; antenna brown, with 14 articles, each with scattered short setae and a few long setae apically; compound eyes round, of moderate size; ocelli not visible owing to preservation of head cuticle; Y-shaped ecdysial cleavage lines and fontanelle not evident (obscured by folding of head cuticle; however, in living Stylotermitidae the fontanelle is exceptionally small and often not visible). Pronotum brown, with scattered, long, fine, erect setae; anterolateral angle acutely rounded, posterior lateral angles broadly rounded, with small medial emargination along anterior border. Legs brown with sparse, short setae except more numerous and stout on tibiae and tarsi; tibial spur formula 2-2-2, perhaps with a single outer spine present on protibia (difficult to discern in holotype), articulating bases of spurs oblique; tarsi trimerous, apical tarsomere longer than combined lengths of basitarsus and second tarsomere, second tarsomere projecting apically beneath base of apical tarsomere; pretarsal claws simple, arolium absent. Forewing scale large, overlapping hind wing scale, humeral margin faintly convex, apical margin straight, CuP (claval fissure) gently arched, meeting posterior margin of scale well before suture, scale with numerous long, erect setae, particularly along humeral margin, without short setae; C and R more darkly pigmented than remaining veins; Sc apparently short, terminating within scale; veins more separated apically than proximally; Rs unbranched, running close and parallel to costal margin, slightly more widely separated from margin apically than proximally; M about midway between R and CuA, branching twice in apical quarter of wing, reaching to wing apex, apical branches of M strongly arched posteriad, such that apices meet wing margin posterior to wing apex; CuA with 10 primary branches reaching to posterior wing margin, apicalmost termination of CuA just posterior to wing apex; veins with sparse, minute setulae; membrane completely bare, between major veins reticulate and with strong, apically-slanting veinlets, particularly midway between R, M, and CuA. Hind wing scale with straight apical margin (suture). Abdomen brown to dark brown; largely crushed and obscured in holotype.

Etymology.

The specific epithet is a patronym honoring Prof. Kumar Krishna, world authority on living and fossil termites, in recognition of his many contributions to the subject.