Baetis (Tenuibaetis) panhai Suttinun et al. 2022

Kluge, Nikita, Srinivasan, Pandiarajan, Sivaruban, T., Barathy, S. & Isack, Rajasekaran, 2023, Contribution to the knowledge of the subgenus Tenuibaetis Kang & Yang 1994 (Ephemeroptera, Baetidae, Baetis s. l.), Zootaxa 5277 (2), pp. 201-258 : 246

7. Baetis (Tenuibaetis) panhai Suttinun et al. 2022

( Figs 230–241 )

Tenuibaetis panhai Suttinun, Gattolliat & Boonsoong 2022: 168 (larvae).

Material examined. THAILAND, river Pai upstream Pai, 5–14.II.2015, coll. N. Kluge & L. Sheyko: 1 L-S♁, 1 L/S♁, 10 larvae .

Additional descriptions

Larva. CUTICULAR COLORATION ( Figs 238–239 ; Suttinun et al. 2022: figs 1A–D): Head brown. Pronotum nearly uniformly brown ( Fig. 238 ). Mesonotum brown, either with wide, contrasting V-shape blank, or with less contrasting blank ( Fig. 238 ), or without it. Thoracic pleura brownish, sterna colorless. Legs brown with ochre; fore femur with proximal blank oval ( Figs 232–234 ). Abdominal terga I– III nearly uniformly brown; tergum IV from brown with more or less expressed lateral blanks ( Fig. 239 ), to entirely colorless; terga V – VIII nearly uniformly brown; terga IX –X either entirely colorless, or at least lighter than others. Abdominal sterna I– VIII from ochre to brown, with sternum VIII darkest; sterna IX –X colorless. Caudalii uniformly brown.

HYPODERMAL COLORATION: Not expressed; before molt to subimago, as in subimago ( Fig. 237 ).

SHAPE AND SETATION. Described and figured by Suttinun et al. 2022. Additional characters:

On each femur, stout two-channel setae forming row along outer side of femur (including two subapical setae) elongate, blunt, distally widened and flattened ( Figs 232–234 ). Anterior-apical margin of femur with small, two-channel setae, as on tibiae. Stout setae on anterior side of femur mostly elongate, distally widened and rounded, varying from large to small ( Figs 232–234 ).

Stout, two-channel setae on outer side of fore tibia small ( Fig. 235 ); stout, two-channel setae on outer sides of middle and hind tibiae significantly larger ( Fig. 236 ). Each tibia with stout, clavate, two-channel setae along patella-tibial suture ( Figs 235–236 ).

Denticles on posterior margins of abdominal terga II –X bluntly triangular ( Suttinun et al. 2022: fig. 3H); absent or sparse on tergum I. Denticles on posterior margin of sterna absent.

Subimago. CUTICULAR COLORATION: Mostly colorless, with some sutures of mesonotum and some pleural sclerites contrastingly brown ( Fig. 240 ).

HYPODERMAL COLORATION: Head, thorax, legs and abdomen ochre; abdominal terga I– IX with contrasting reddish-brown band bordering posterior margin, with more or less expressed lateral reddish lateral maculae ( Figs 237, 240 ).

Imago. Unknown.

Dimension. Forewing length 4 mm.

Distribution. Thailand.

Comments. The original description of Tenuibaetis panhai contains description and figures of the foreleg, but not of other legs. Photos of the holotype kindly sent by Ch. Suttinun, show that stout setae on outer side of middle and hind tibiae are enlarged (as in Fig. 236 ). The drawing of femoral patch ( Suttinun et al. 2022: fig. 3B–C) shows its setae directed proximally; actually they are directed distally, as in all other Baetofemorata ( Fig. 231 ).

Figures

FIGURES 230–236. Baetis (Tenuibaetis) panhai, exuviae of larval legs. 230–231, proximal-posterior portion of fore femur with villopore (230, anterior side; 231, posterior side); 232–234, fore, middle and hind legs; 235–236, fore and middle tibiae.

FIGURES 237–241. Baetis (Tenuibaetis) panhai. 237, abdomen of male subimago extracted from mature larva; 238, larval exuviae of half of pronotum and mesonotum; 239, larval exuviae of abdomen; 240, male subimago; 241, subimaginal gonostyli crumpled under larval cuticle.