Borneo ♂ abd. + app. 29 - 33, hw. 23 - 25 mm. Sumatra ♂ abd. + app. 31 - 31.5, hw. 24.5 - 25 mm. M. A. Lieftinck: Descriptions and records of S. E. Asiatic Odonata. 343 Female. — The ♀ of impar is probably less rarely come across than that of E. tricolor and its allies. The anterior parts of the head are bright greenish-yellow instead of blue, the labrum having occasionally a pale blue tint. Pale frontal spots band-like, broadly connected in the median line. Dorsal thoracic fascia similar in principle to the male but dark reddishbrown instead of black. Sides dirty bluish- or olive-green with a diffuse brownish spot at the dorsal end of the humeral and second lateral sutures, and traces of brownish streaks near the lower margin of the mesepimeron, the metepimeron and round the spiracle. The dorsal margin of the pleurae is continuously bordered with dark brown. Venter of thorax pruinosed white. Wings hyaline, or almost so; bases faintly yellowish. Abdomen brownish-black. There are small but quite distinct dorso-lateral yellow spots placed transversely along the bases of segm. 3 - 7; these spots are almost fused posteriorly with a lateral system of pale marks, consisting merely of straight, longitudinal stripes, greenish-yellow in colour. Length: abd. + app. 2 5 - 2 7, hw. 23.5 - 25 mm. E. impar is decidedly a shade-loving insect, preferring brooks and small streams in the depth of the forest. Apparently widely distributed and not uncommon in such places, where the males may be found perched on twigs in sunlit-openings high overhead.
Sumber: Descriptions and records of South-East Asiatic Odonata (II)