Epeorus (Epeorus) bifurcatus Braasch & Soldan , 1979

Boonsoong, Boonsatien & Braasch, Dietrich, 2013, Heptageniidae (Insecta, Ephemeroptera) of Thailand, ZooKeys 272, pp. 61-93 : 68

Epeorus (Epeorus) bifurcatus Braasch & Soldan, 1979

Epeorus bifurcatus Braasch & Soldán, 1979: 266, 270, Figs 15-22. (orig.)

Epeorus (Epeorus) bifurcatus Braasch & Soldán, 1979 (comb.)

Larva.

Braasch and Soldán 1979: 266, 270, Figs 15-22; Nguyen and Bae 2004a: 21-22, Figs 7-12.

Adult.

Unknown.

Eggs.

Unknown.

Distribution.

Tak province, highway 1090, km 64.5, mountain creek, riffle and run habitats; limy, gravel; leaf packs, wood, secondary forest; 750 m asl, c 16°30'N, 99°00'E; 14.1.2009 (leg. Freitag).

Diagnosis.

The larva of Epeorus bifurcatus can be distinguished from that of itscongeners by pairs of small submedian dorsal tubercles on tergites with acute spines and gill 1 larger than gill 3. In the Figs 7-8 of Nguyen and Bae (2004a) some characters (the femoral spot, the rim of hairs of the hind margin of head and pronotum) are not described. Furthermore, according to our material, the head of the type species is smoothly trapezoid without markings in anterior median half, however, the head is transversely ellipsoid with a broad dark band between its front and hind margins.

Habitat and biology.

Nguyen and Bae (2004a) noted that the larva of Epeorus bifurcatus occur in mountain streams ranging between 200-600 m. They were found on the underside of stones in fast flowing sections of the streams.

Remarks.

Braasch and Soldán (1979) described this species based on larval specimens and original descriptions are written in Germany. Then, Nguyen and Bae (2004a) described the larva of Epeorus bifurcatus in English based on specimens from northern Vietnam, near the holotype locality.