7. Branchiobaetis jhoanae sp. nov.

Figs 22, 23, 25b, 26e, 29

Type material.

Holotype. Philippines • S. Luzon, Sorsogon, Bulusan, San Roque; 12°44'N, 124°05'E; 290 m; 26. IX. 1996; leg. J. Mendoza; larva on slide; GBIFCH00592344; PNM. Paratypes. Same data as holotype; 1 larva on slide; GBIFCH00763660; MZL. Philippines • Cebu, Cebu City, Cantipla Uno; 10°20'48"N, 123°51'57"E; 100 m; 11. IX. 1996; leg. J. Mendoza; larva on slide; GBIFCH00592341; AdMU; larva in alcohol; GBIFCH00515474; AdMU • Cebu, Cebu City, Bgy. Tabunan, sitio Cantipla 1; 10°24'56"N, 123°49'02"E; 753 m; 16.XII.1998; leg. Panganthion; larva on slide; GBIFCH00654920; MZL; 2 larvae in alcohol; GBIFCH00515475, GBIFCH00980901; AdMU.

Differential diagnosis.

Larva. Following combination of characters distinguish B. jhoanae sp. nov. from other species of Branchiobaetis gen. nov.: A) labial palp segment II with small, rounded protuberance; segment III slightly pentagonal, apically pointed, ca. 0.7 × length of segment II, ca. 1.4 × as long as width at base, approx. as long as maximal width (Fig. 22h); B) dorsal margin of femur with row of long, spine-like setae (Fig. 23a); C) posterior margin of tergites: I smooth, without spines; II-IX with triangular spines (Fig. 23d); posterior margin of sternites: I-VI smooth, without spines; VII-IX with small, spaced, triangular spines; D) paraproct without short, stout, apically rounded setae along posterior margin (Fig. 23f).

Description.

Larva (Figs 22, 23, 25b, 26e). Body length 5.8-7.0 mm. Cerci: ca. ½ of body length. Paracercus: ca. 2/3 of cerci length. Antenna: ca. 2.5 × as long as head length.

Colouration (Fig. 25b). Head, thorax, and abdomen dorsally brown; head, thorax and abdomen ventrally light brown to brown. Legs light brown to brown, large brown areas along dorsal margin, apex and on medial surface of femur. Caudalii light brown, primary swimming setae dark brown.

Antenna (Fig. 23g). Scape distally with short, stout, apically rounded setae.

Labrum (Fig. 22a). Length 0.6 × maximum width. Submarginal arc of setae composed of 7-9 long, simple setae.

Right mandible (Fig. 22b, c). Incisor blade-like with three denticles; kinetodontium with four denticles. Margin between prostheca and mola straight, with minute denticles.

Left mandible (Fig. 22d, e). Incisor blade-like with four denticles; kinetodontium with three denticles. Margin between prostheca and mola straight, with minute denticles towards subtriangular process.

Both mandibles with lateral margins slightly convex.

Hypopharynx and superlinguae (Fig. 22f). Lingua as long as superlinguae. Lingua longer than broad; medial tuft of stout setae well developed, long. Superlinguae distally rounded; lateral margins rounded; fine, long, simple setae along distal margin.

Maxilla (Fig. 22g). Galea-lacinia ventrally with two simple, apical seta under canines. Medially with one pectinate, spine-like seta and 4-6 medium, simple setae. Maxillary palp approx. as long as galea-lacinia; palp segment II approx. as long as segment I; setae on maxillary palp fine, simple, scattered over surface of segments I and II.

Labium (Fig. 22h). Inner margin of glossa with eight or nine spine-like setae, increasing in length distally; apex with two long and one medium, robust, pectinate setae; outer margin with approx. five spine-like setae; Paraglossa with one simple seta in anterolateral area and one simple seta in posterolateral area; dorsally with three long, spine-like setae near inner margin. Labial palp with segment I 0.7 × as long as length of segments II and III combined. Segment I ventrally with short, fine, simple setae. Segment II with small, rounded, distomedial protuberance; distomedial protuberance 0.3 × width of base of segment III; ventral surface with short, fine, simple setae; dorsally with five or six spine-like setae near outer margin. Segment III slightly pentagonal, apically pointed; length approx. maximum width; ventrally covered with short, spine-like, simple setae and short, fine, simple setae.

Foreleg (Fig. 23a-c). Ratio of foreleg segments 1.3:1.0:0.6:0.2. Femur. Length ca. 3 × maximum width. Dorsal margin with row of 14-21 long, curved, spine-like setae, basally denser. Many short, stout setae scattered along ventral margin. Apex rounded, with pair of long, spine-like setae and some short, stout setae. Tibia. Dorsal margin with row of short, stout setae. On surface few such setae along patella-tibial suture. Ventral margin with row of short, curved, spine-like setae, on apex a tuft of fine, simple setae. Tarsus. Dorsal margin with row of short, stout setae and fine, simple setae. Claw with one row of nine or ten denticles.

Terga (Fig. 23d). Surface with irregular rows of U-shaped scale bases and fine simple setae. Posterior margin of tergites: I smooth, without spines; II-IX with triangular spines. Posterior margin of sternites: I-VI smooth, without spines; VII-IX with small, spaced, triangular spines.

Tergalii (Figs 23e, 26e). Tracheae extending to inner and outer margins; indistinct, broad, light brown band along main trunk of tracheae on anal side. Tergalius I as long as 1/2 of segment II, tergalius IV as long as length of segments V and 1/4 VI combined, tergalius VII as long as length of segments VIII and 1/4 IX combined.

Paraproct (Fig. 23f). Posterior margin with 14-18 stout spines. Without short, stout setae near posterior margin. Surface scattered with scale bases and micropores.

Etymology.

Dedicated to Dr. Jhoana M. Garces (Philippines) for her great contribution to the knowledge of mayflies from the Philippines.

Distribution.

Philippines: Luzon, Cebu (Fig. 29).

Biological aspects.

The specimens were collected on altitudes between 100 m and 750 m, on Cebu in stream runs on bottom gravel or rock surface.