The genitalia of the Dutch Aegeriidae

The Lepidopterous family Aegeriidae (Glass Wings) represents a compact natural group of species, easily recognisable by for the greater part hyaline wings (fig. 1). The group has been studied chiefly by F. le Cerf (1917) and G. F. Hampson (1892, 1919), and for North American species, by G. P. Engelhardt (1946). However, the genitalia received only moderate attention. Engelhardt figured those of the North American species, and Pierce & Metcalfe (1935), those of species occurring in the British Isles. Both these publications are not so easily available to the wider circle of Dutch lepidopterists; this may justify the publication of the present small iconography. The Aegeriidae are moths of moderate size, flying rapidly in bright sunshine. The head is with appressed scales or rather rough. Ocelli are present. The antenna are usually thickened and spindle-shaped, tapering to a point, with a minute pencil of cilia at the tip. The proboscis is usually developed. The labial palpi are moderate, curved and ascending. The posterior tibiae are roughly scaled or haired (fig. 2). The wings (fig. 1) are narrow, elongate, dilated and partly devoid of scales. Usually a discal mark (discoidal vein), costa, often also termen, are scaled; the disc of wing is variably scaled, with a longitudinal hyaline area. The hind wing is scaled only along the edge and along upper part of discoidal vein. The fore wing has normally twelve veins, the hind wing eight veins, but vein 8 merges with the costal margin. Characteristic is a specialized locking mechanism between the fore and hind wings formed by the folded dorsal and costal margins, respectively, gripping into each other. A frenulum is also