Figs. 2E, 4E, 4J, 5B, 6 E–F, 7E, 9L, 100A
Material examined. Holotype (male): Thailand: Nakhon Nayok, Khao Yai, elev. 700 m (14°23'N, 101°23'E), 15– 18.x.1990, leg. S. Ingrisch— 1 male (Bonn ZFMK).
Other specimens: Same locality as holotype, 5.iv.1995, leg. S. Ingrisch— 1 female (paratype) (Bonn ZFMK).
Diagnosis. E. serricauda is the so far only species of the genus, in which the projections of the male ninth abdominal tergite are not tooth- or spine-like but disc-shaped with serrate margin; below that disc there is a small inconspicuous tooth (Figs. 6 E–F).
Description. Large species (Figs. 4E, 4J). Head: Face ovoid; fastigium verticis about twice as wide as scapus; ocelli indistinct; fastigium frontis separated from fastigium verticis by a very fine suture; a pair of distinct subantennal furrows, starting at internal angle of antennal scrobae, separates the central area of face from the lateral areas and fuse ventrally with clypeo-frontal suture; clypeo-frontal suture interrupted in middle; subocular furrows also distinct (Fig. 5B). Abdominal tergite three only with extremely minute stridulatory pegs.
Wings reaching about tip of stretched hind tibiae (Fig. 4E). Tegmen: Radius with two branches, both forked near tip; media anterior fused in basal area with radius; media posterior absent; cubitus anterior forks before midlength into two veins, CuA1 and CuA2; cubitus posterior undivided, free throughout; with 5 anal veins.
Legs: Fore coxa with a rather large spine at fore margin; fore and mid femora unarmed; fore and mid tibiae with four pairs of large, on mid tibiae comparatively short, ventral spines and one pair of smaller ventral spurs; hind femur with 5–10 external and 6–7 internal spines on ventral margins; hind tibia with spaced spines on both dorsal margins, ventral margins with one pre-apical spine each; with 3 apical spurs on both sides.
Coloration. General color uniformly green when alive (Fig. 100A); vertex unicolored; disc of pronotum unicolored, hind margin hardly darker. Legs of general color. Face unicolored green; eyes red brown; basal angles of clypeus black (female) or green and clypeo-frontal sutures darkened (male). Tegmen semi-transparent white with green veins; in center yellowish infumate; hind wing semi-transparent white with green veins; apart from marginal areas cells with large dark brown spots.
Male. Ninth abdominal tergite semi-globular: prolonged and down-curved laterally and apically; in descending posterior area furrowed in midline and before apex split and granular, on both sides of the split area with a small disc with granular margin and below that disc with a fine styliform projection, both projecting mediad (Figs. 6 E– F). Epiproct and paraproctes distinct. Subgenital plate almost twice as wide as long; apical margin wide, slightly obtuse-triangularly excised; styli inserted laterally at apical margin. Phallus membranous.
Female. Seventh abdominal sternite together with its apical projection appearing triangular with rounded angles; apical projection covering centro-basal area of subgenital plate. Subgenital plate elongate triangular with rounded apex; only margin and a small area at tip sclerotised, remainder membranous and shallowly grooved (Fig. 7E). Base of ovipositor with a small sclerite before base of ventral valves. Ovipositor of medium length, distinctly but not strongly curved dorsad, margins slightly and gradually narrowing towards tip; dorsal margin with a slight expansion before tip (Fig. 9L).
Measurements (1 male, 1 female).—body w/wings: male 54, female 58; body w/o wings: male 36, female 43; pronotum: male 8, female 9; tegmen: male 40, female 42; tegmen width: male 16; hind femur: male 18, female 19; antenna: male 110; ovipositor: female 17 mm.
Etymology. The name of the new species refers to the apical projections of the male ninth abdominal tergite. From Latin serre (serrated) and cauda (tail).