Ephemeroidea Hampson
Genus Details
Type species: ariel Hampson, Burma.
The wings of the three species in this genus are predominantly transparent, those of the type species most extensively so except for dark veins and margins. The venation of the type species was illustrated by Hampson (1892 [1893]). The forewing cell is narrowed towards the base. Veins R1-4 arise independently from the cell, then the next three veins form a branching system ((R5, M1) M2). CuA1 and CuA2 diverge from M3 to converge on CuP. All hindwing veins are unstalked, and those from the cell are reduced in number from six to four. The male antennae are bipectinate, three-quarters of the length of the forewing in ariel and flavicincta Hampson (Burma), the pectination tapering away distad; the rami are bristly with fine setae in virescens Snellen, but the antennae are much shorter.
The male abdomen (virescens) has no modifications over the basal part, but the eighth segment has a tergite with a straight anterior margin and lateral apodemes, and extends distally in the form of a semi-oval. The sternite is a slender triangle that expands laterally at its anterior into splayed apodemes. The male genitalia have a simple uncus and a small saccus, but the valves are triangular with a highly complex sacculus and what appears to be an ‘Artona-finger’ (see p. 16) from the ventral angle of the triangle. There is a zone of long setae along the outer basal edge of the sacculus somewhat as in Palmartona catoxantha Hampson. The aedeagus vesica is as large as the aedeagus, expanding to a distal zone of very long cornuti, the largest a slender spine, the rest a series of increasingly fine ribbons and threads that have barbs along their length. Some of these features, particularly the presence of an ‘Artona finger’ and association with Gramineae (see below), suggest that placement in the Artonini might be a valid option, a suggestion endorsed by G.M Tarmann (pers. comm.). The valve structure in entirety shows similarity in its complexity to that of Artona gracilis Walker (Japan), as does that of the aedeagus vesica.
