Dudgeodes palnius Selvakumar, Sivaramakrishnan & Jacobus

Selvakumar, C., Sivaramakrishnan, K. G., Jacobus, Luke M., Janarthanan, S. & Arumugam, M., 2014, Two new genera and five new species of Teloganodidae (Ephemeroptera) from South India, Zootaxa 3846 (1), pp. 87-104 : 95-99

Dudgeodes palnius Selvakumar, Sivaramakrishnan & Jacobus , n. sp.

Figs. 59–77 .

Materials examined. Holotype: Male larva, India, Tamil Nadu, Palni hills, Perumal Malai stream, 10o16’ 15.39 N, 77o33’ 15.83 E, 1484 m; 28.IX.2013, Colls. C. Selvakumar& K. G. Sivaramakrishnan [ZSI-I/E 13].

Paratypes: Four larvae, India, Tamil Nadu, Upper Kodaiyar, 08º31' 50.2" N, 77º 21' 33.0" E, 1299 m; 06.IX.2010, Colls. C. Selvakumar & K. G. Sivaramakrishnan [ZSI-I/E 14].

Two larvae, same data as holotype [UM]; One larva, India, Tamil Nadu, Tirunelveli, Gadana river, Kallar, 0 8o 48'04.5" N, 77o18'05.3" E, 144 m; 20.VII.2013, Colls. C. Selvakumar & K. G. Sivaramakrishnan [UM]. Three larvae, India, Tamil Nadu, Tirunelveli, Puliyarai, Kannupulimedu, 0 8o 56'20.35" N, 77o12'25.74" E, 164 m; 17.VII.2013, Colls. C. Selvakumar & K. G. Sivaramakrishnan [UM]. One larva, India, Tamil Nadu, Tirunelveli, Ramanathi river, 0 8o 50'53.4"N, 77o18'51.2" E, 237 m; 21.VII.2013, Colls. C. Selvakumar & K. G. Sivaramakrishnan [UM].

Description. Larva.

Body length up to 3.5 mm and 3.0 mm, without cerci, in female and male larvae respectively; cerci length subequal to body length. General colouration highly variable, ranging from light to dark brown; young specimens generally paler; legs light to medium brown, with femora bearing 4 characteristic maculae ( Fig. 59 ).

Head: Outer margin of head fringed with row of short, basally forked setae from in front of eyes to labrum insertion. Antennae length 1.2 times head width, flagellum with 15 segments. Dorsal part of male eyes blackish. Labrum compact, ca. 2 times wider than long, with smooth anterior emargination; dorsal face covered medially by scattered simple and long setae; anterior margin with row of small, thin setae ( Fig. 60 ). Hypopharynx with superlinguae oval with row of long, simple setae at apex ( Fig. 61 ). Mandibles slender with one thin seta in middle of outer margin; left mandible ( Fig. 64 ) with outer incisor consisting of one slightly concave teeth; inner incisor with two teeth inserted transversely, one smaller and pointed, one large and rounded, prostheca small; no setae below mola; right mandible ( Fig. 65 ) with outer incisor composed of one large tooth, slightly indented medially; inner incisor with two teeth; prostheca reduced, with appearance of cluster of thin setae; row of 7 long and thin setae below mola and several short setae above mola. Maxilla slender, with well-developed canina, two indented dentisetae and three long setae on inner apical region and cluster of long, simple setae at crown; inner margin at base of lacinia, with two feathered and long setae, one dorsally and one ventrally; maxillary palp highly reduced ( Fig. 62 ). Submentum well-developed laterally; glossae and paraglossae partially fused; paraglossae larger than glossae; labial palp three-segmented, segments 1 and 2 clearly visible, without constriction; segment 3 ca. 2.5 times as long as wide ( Fig. 63 ).

Thorax: Prothorax and mesothorax with 4 rounded tubercles on dorsal surface; outer margin fringed with row of short, basally-forked setae. Forefemur dilated, ca. 1.5 times longer than wide; outer margin covered by stout and long setae, meeting transverse row of both long and stout pointed setae across dorsal face; without thin setae at apex; inner margin with short row of long and thin setae proximally, reaching distally to transverse row ( Figs. 66, 67 ). Middle and hind femora similar, more slender, ca. 2 times longer than wide; dorsal and inner margins each with row of long and stout setae ( Figs. 69, 70 ). Tibia with row of long and stout setae on inner margin, and row of long and thin setae on outer margin ( Fig. 68 ). Tarsal claw hooked, bearing three or four blunt teeth medially, and two pointed teeth subapically; outer tooth well developed, inner one smaller; apex of claw with two rows of three or four thin setae laterally ( Fig. 71 ).

Abdomen: Terga each with moderately developed median tubercle on segments I and X, more highly developed on segments II–IX ( Fig. 72 ). No posterolateral projections on segments II–IV, but distinct on segments V–IX ( Fig. 73 ). Lateral margins of terga with long thin setae. Gills on segments II–V ( Figs. 74–77 ); gill II with dorsal lamella operculate, oval and with margin entire; gills III–V with dorsal lamella incised medially; ventral lobe flabelliform, well-developed and purple on gills II–IV. Cerci with stout setae every two or three segments; setae longer than length of corresponding segment.

Winged stages. Unknown.

Etymology. This species is named after the Palni hills of the Western Ghats from which type specimens were collected.

Diagnosis. Dudgeodes palnius , n. sp., can be distinguished from other species of Dudgeodes and from the apparently similar species of D. hutanis by the following combination of characters: (i) apex of forefemur without seta ( Fig. 67 ); (ii) a single ventral long seta on inner margin of galea-lacinia ( Fig. 62 ); (iii) labial palp segments 1 and 2 clearly visible, without constriction ( Fig. 63 ); (iv) left mandible with outer incisor consisting of one slightly concave teeth ( Fig. 64 ) and (v) right mandible with outer incisor composed of one large tooth, slightly indented medially, with a row of seven long and thin setae below mola ( Fig. 65 ).

Figures

FIGURES 59 – 71. Dudgeodes palnius, n. sp. 59. Larva, dorsal habitus; 60. Labrum; 61. Hypopharynx; 62. Maxilla; 63. Labium; 64. Left mandible; 65. Right mandible; 66. Foreleg; 67. Transverse row of setae on forefemur; 68. Foretibia with row of setae; 69. Midleg; 70. Hindleg; 71. Claw.

FIGURES 72 – 77. Dudgeodes palnius, n. sp. 72. Abdominal median tubercles; 73. Abdomen, ventral view; 74 – 77. Gills II – V.