Digitipes jangii, Joshi, Jahnavi & Edgecombe, Gregory D., 2013

Joshi, Jahnavi & Edgecombe, Gregory D., 2013, Revision of the scolopendrid centipede Digitipes Attems, 1930, from India (Chilopoda: Scolopendromorpha): reconciling molecular and morphological estimates of species diversity, Zootaxa 3626 (1), pp. 99-145 : 113-115

Digitipes jangii n. sp.

( Figs 46–56 )

Digitipes putative species 5. Joshi and Karanth, 2012: figs 2, 3, 6. Digitipes putative species 6. Joshi and Karanth, 2012: figs 2, 3, 6.

Type specimens. Holotype CES08912, male, from Kudremukh National Park, Karnataka, India, 13°20052 N 75°19289 E, leg. J. Joshi, vii.2008. Paratypes: CES08915, male, CES08907, CES08922, females, from type locality, same collection; CES07219, CES07223, CES07226, CES07230, from Anshi-Dandeli Tiger Reserve, Karnataka; CES07230, from Dodamanne Ghat, Karnataka; CES08288, from Talacauvery Reserve Forest, Karnataka; CES08930, from Bombay point, Mahabaleshwar Reserve Forest, Maharashtra; CES 091020, from Bisale Ghat Reserve Forest, Karanataka. All leg. J. Joshi, 2007–2010.

Etymology. For B. S. Jangi, in recognition of his work on the Scolopendridae of India, including the identification of Digitipes .

Diagnosis. Digitipes with basal three or four antennal articles glabrous both dorsally and ventrally. Forcipular tooth plates wider than long. Tergite paramedian sutures complete from TT4 or 5; tergites smooth, lacking longitudinal median ridge or keels. Coxopleural process long, slender, lateral spine usually present. Leg 20 without tarsal spur. Spines on ultimate leg prefemur moderate to strong. Distomedial process on ultimate leg femur of male short, blunt.

Description. Length to 47 mm. 17 antennal articles; basal three (five individuals) or four (six individuals) articles glabrous both dorsally and ventrally. Longitudinal median furrow on anterior 20% of cephalic plate. Short paired longitudinal furrows on posterior part of cephalic plate ( Fig. 46 ).

Anterior part of cephalic plate and basal (glabrous) part of antenna blue, remainder of cephalic plate usually brown; T1 variably light brown or mostly blue; tergites often mostly blue from T2 to middle of body and increasingly brown in posterior segments but may be dark brown from T2; legs usually light blue, in some specimens dark blue.

Forcipular coxosternal tooth plates wider than long ( Figs 47, 48 ), with four main teeth, inner two grouped together, the outer tooth smaller than the inner three; base of tooth plates defined by relatively obtuse oblique sutures diverging at 140–145°. Trochanteroprefemoral process with two distinctly defined teeth along inner margin.

Second maxillary claw with slender accessory spurs.

Tergites with paramedian sutures complete from TT4 or (usually) 5. Tergites marginate starting from 7 to 13, most commonly from 8 or 9. Tergites smooth ( Fig. 55 ), lacking median ridge or keels. Paramedian sutures 20–35% length of sternites in mid body region.

First three or four pairs of legs (two pairs in a single specimen) with two tarsal spurs, the subsequent up to 19 with one, 20 without tarsal spur (except one individual). Tibial spur on leg 1 only. Femoral spur usually lacking on leg 1, present in one individual.

Tergite of ultimate leg-bearing segment with gently convex lateral margins that converge posteriorly; posterolateral margins straight, variably pointed posteromedially ( Fig. 50 ). Sternite of ultimate leg-bearing segment with sides converging posteriorly, weakly convex outwards, posterior margin moderately concave ( Fig. 51 ).

Coxopleural process long, slender, with two apical spines, mostly with a lateral spine on each side ( Figs 49, 51 ), a few individuals with lateral spine on one side only, one lacking spines on both sides. Pores relatively dense, approximately bimodal mix of large and small pores; pore field extending close to but not reaching dorsal margin of coxopleuron ( Fig. 49 ); non-porose area on process narrow, at least half length to posterior margin of sternite of ultimate leg-bearing segment, sometimes extending to that margin. Ultimate leg prefemur with width at distal end about one-third its length; prefemoral spines usually large, distally curved ( Fig. 52 ): VL 3, VM 2, DM 1 or 2, apart from one individual with VL 1/2, VM 1, DM 0. Distomedial process in males blunt, not extending to distal end of femur on its dorsal side ( Fig. 53 ); groove on medial surface of femur confined to distal end of femur or as much as half length of femur ( Fig. 54 ); slightly flattened and variably depigmented area on medial surface of femur bearing dense field of fine pores. Distomedial end of ultimate leg tibia in male either bears (CES08912) or lacks (CES08915, CES 091020) a weak rounded process similar to that on femur. Ultimate leg tarsus 1 1.6–1.8 times length of tarsus 2; tarsus 1 2.4–6 times longer than pretarsus; pretarsus with pair of short accessory claws.

Discussion. Putative species 5 and 6 had previously been observed not to be differentiated on the environmental and morphological axis (Joshi and Karanth 2012). In the current revision we treat them as one species but recognise it as distinct from all previously named congeners. Its distinctive features include the presence of four glabrous antennal articles in some specimens, relatively short forcipular tooth plates, a slender coxopleural process, robust prefemoral spines, and a short femoral process on the male ultimate leg. It is also the only species in our sample apart from D. periyarensis with individuals (4 of 11 specimens, all from the same population) having two DM spines on the ultimate leg prefemur; other Indian Digitipes have at most one DM spine. A character of potential taxonomic importance is a small distomedial process on the ultimate leg tibia in the sole mature male of PS5 (the holotype of D. jangii ) versus its absence in two mature males of PS6. We are reluctant to attribute diagnostic value to this difference without additional samples.

Figures

FIGURES 46 – 51. Digitipes jangii n. sp. 46, 50, 51, CES 08912 (holotype male); 47 – 49, CES 08915 (paratype male). 46. Cephalic plate and T 1, dorsal view, scale = 2 mm. 47. Forcipular segment, ventral view, scale = 1 mm. 48. Tooth plates, ventral view, scale = 0.5 mm. 49. Coxopleuron, lateral view, scale = 1 mm. 50. Tergite of ultimate leg-bearing segment, dorsal view, scale = 1 mm. 51. Coxopleuron and sternite of ultimate leg-bearing segment, ventral view, scale = 0.5 mm.

FIGURES 52 – 56. Digitipes jangii n. sp. CES 08912 (holotype male) except Fig. 56, CES 08915 (paratype male). 52. Ultimate leg prefemur, ventral view, scale = 0.5 mm. 53. Ultimate leg femur, dorsal view, scale = 0.5 mm. 54. Ultimate leg femur, medial view, scale = 0.5 mm. 55. TT 18 – 20, dorsal view, scale = 0.5 mm. 56. Spiracle on segment 3, scale = 0.25 mm.