Baetis (Tenuibaetis) fujitanii Kaltenbach & Gattolliat 2019

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 : 227-228

4. Baetis (Tenuibaetis) fujitanii Kaltenbach & Gattolliat 2019

( Figs 125–145 )

Baetis (Tenuibaetis) fujitanii Kaltenbach & Gattolliat, 2019 : (larva).

Material examined ( ZIN). INDONESIA, JAVA: Bogor, river Liwung , 31.VIII–2.IX.2012, coll. N. Kluge & L. Sheyko: 2 L-S-I♁, 1 L-S-I ♀ , 1 L-S ♀, 247 larvae; Bogor, river Sadane , 2.IX.2012, coll. N. Kluge: 4 larvae .

Additional descriptions

Larva. CUTICULAR COLORATION: Head brown ( Fig. 125 ). Pronotum brown to brown with blanks, with sigilla lighter than background; mesonotum and fore protoptera brown, with more or less contrasting blanks ( Fig. 126 ). Thoracic pleura brownish, sterna colorless. Legs with brown and colorless areas ( Figs 129–131 ); if fore femur with expressed proximal blank, shape of proximal blank subtriangular or comma-like, with inner-distal angle stretched distally ( Fig. 29 ). Abdominal terga nearly uniformly brown; tergum IV lighter laterally ( Fig. 127 ; Kaltenbach & Gattolliat 2019: fig. 1a). Caudalii brownish.

HYPODERMAL COLORATION: Either not expressed, or abdominal terga with dark brown line on posterior margin and other markings as in imago (as in Figs 135, 141 ).

SHAPEAND SETATION:Mouthpartsasinoriginaldescription( Fig.125 ; Kaltenbach&Gattolliat2019:fig.2a–h).

Hind protoptera present ( Kaltenbach & Gattolliat 2019: fig. 3d).

Stout two-channel setae forming row along outer side of femur (including two subapical setae) elongate, blunt, distally widened and flattened ( Figs 129–131 ). Anterior-apical margin of femur with small, pseudo-bifurcate setae, as on tibiae. Anterior side of femur with colorless oval scales in semicircular sockets ( Fig. 132 ) (as on abdomen). Stout setae on anterior side of femur two-channel, blunt or clavate, mostly short; on each leg, one or few most distal setae long and clavate ( Figs 129–132 ; Kaltenbach & Gattolliat 2019: fig. 3a).

Tibia of each leg with small, pseudo-bifurcate setae on outer side; stout setae along patella-tibial suture small, two-channel ( Figs 133–134 ).

Denticles on posterior margins of all terga I–X blunt ( Kaltenbach & Gattolliat 2019: fig. 3c), shorter on anterior terga and longer on posterior terga. Denticles on posterior margin of sternum triangular, present only on sternum IX, sometimes also on sternum VIII; in male, row of denticles not interrupted by protogonostyli. Paraproct with small denticles ( Kaltenbach & Gattolliat 2019: figs 3g –h). Tergalii with oval scales on semicircular sockets. Tergalius I much smaller than others ( Kaltenbach & Gattolliat 2019: figs 3e–f). Paracercus significantly smaller than cerci (ibid., fig. 1).

Subimago. CUTICULAR COLORATION: Head colorless, antennae brown. Pronotum colorless. Mesonotum in median part mostly colorless and ochre, laterally with lighter and darker brown areas ( Fig. 137 ). Thoracic pleura and sterna with light brownish and dark brown areas (as in Fig. 215 ). Legs with femora lighter, tibiae and tarsi darker ( Fig. 140 ). Abdominal terga I– VIII medially nearly colorless, laterally diffusively darkened; terga IX –X entirely light (as in Fig. 172 ).

HYPODERMAL COLORATION: As in imago.

Imago, male ( Fig. 135 ). Head ochre. Antennae ochre. Turbinate eyes orange. Thorax ochre with light brown. Forewing with membrane entirely colorless; veins from ochre (nearer to wing base) to brown; pterostigma with few oblique cross veins and disconnected vein fragments. Hind wing full-sized, colorless, with short and non-hooked costal projection, with 2 longitudinal veins ( Fig. 138 ). Legs uniformly ochre ( Figs 142–143 ). Middle and hind tarsi with 2 apical spines (on 1st+2nd and 3rd segments). Abdominal terga and sterna ochre with brownish or reddish, with lateral areas darker and median areas lighter; terga IX –X lighter than others; terga I– IX or some of them with contrastingly dark brown band bordering posterior margin and not reaching lateral margins ( Figs 135, 141 ). Cerci ochre. Gonostyli ochre; 1st segment relatively narrow, only slightly narrowing toward apex (nearly parallel-sided); 3rd (terminal) segment short and petiolate ( Figs 144–145 ). Gonovectes gently bent, light brownish. Sterno-styligeral muscle completely absent.

Imago, female ( Fig. 136 ). Coloration similar to that of male. Hind wing slightly smaller than in male ( Fig. 139 ). All tarsi with 2 apical spines (fore tarsus on 2nd and 3rd segments, middle and hind tarsi on 1st+2nd and 3rd segments).

Dimension. Forewing length 4 mm.

Distribution. Java.

Comparison. B. (T.) fujitanii is similar to B. (T.) frequentus , and there are no characters allowing to clearly separate these species. Larvae of B. (T.) fujitanii from Bogor (the type locality) have rather uniform dorsal coloration, similar in all individuals, while larvae of Ceylonese populations of B. (T.) frequentus have variable coloration. Probably, species-specific character of B. (T.) fujitanii is the fact that the most distal two-channel seta on anterior surface of each femur is much longer than others ( Fig. 132 ).

Figures

FIGURES 125–128. Baetis (Tenuibaetis) fujitanii. 125–127, larval exuviae: 125, head; 126, half of pronotum and mesonotum; 127, abdomen; 128, young larva in natural pose.

FIGURES 129–134. Baetis (Tenuibaetis) fujitanii, exuviae of larval legs. 129–131, fore, middle and hind legs; 132, anterior surface of hind femur; 133–134, middle tibia.

FIGURES 135–143. Baetis (Tenuibaetis) fujitanii. 135, male imago; 136, female imago; 137, subimaginal exuviae of half of mesonotum; 138, male hind wing; 139, female hind wing; 140, exuviae of male fore leg; 141, abdomen of male imago; 142–143, middle and fore legs of male imago.

FIGURES 144–145. Baetis (Tenuibaetis) fujitanii, genitalia of male imagines.

FIGURES 22–30. Baetis (Tenuibaetis) ursinus, larval exuviae (24–29, one and the same magnification). 22, labrum; 23, maxilla and labium; 24, abdomen, 25–27, middle and hind legs; 28, half of pronotum and mesonotum; 29, head; 30, paraproct.

FIGURES 215–224. Baetis (Tenuibaetis) bialatus sp. n. 215, subimaginal exuviae of mesopleuron; 216, subimaginal exuviae of half of mesonotum; 217–218, exuviae of fore and hind legs of male subimago; 219–220, fore and middle legs of male imago; 221, male imago; 222, female imago; 223, subimaginal exuviae of abdominal segments VIII–IX; 224, egg (215–220, holotype).

FIGURES 169–180. Baetis (Tenuibaetis) kaltenbachi sp. n. 169–170, male imago; 171, female imago; 172, subimaginal exuviae of abdomen; 173–174, fore and middle legs of male imago; 175–176, their subimaginal exuviae; 177, subimaginal exuviae of half of mesonotum; 178, hind wing of male imago; 179, the same, female; 180, blunt microlepides on fore tarsus of male subimago (169–170, 172–178, 180, holotype).