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Schrankia
Hübner
Type species:
taenialis
Hübner, Europe.
Synonym: Hypenodes Guenée (type species albistrigatis Haworth, Great Britain = taenialis) praeocc.
This genus is very similar in external appearance to Luceria, particularly the Holarctic and Hawaiian species. There is greater variation in facies in the numerous S.W. Pacific species described by Holloway (1977). The forewings are more a leaden grey or fawnish grey colour, sometimes with a vinous tinge. The reniform is present, dark, and the angled or stepped postmedial is often yellow.
The male abdomen has an eighth segment of the framed corematous type, but only weakly developed. The genitalia have a long, slender uncus, though three of the Pacific species have it more robust and highly modified. The inner margin of the tegumen often has a slight angle or lobe at its ventral extremity. The saccus is usually large, but the juxta is much smaller than in Luceria. The valves are irregularly tapered distally, and bear a complex set of up to three processes over the interior of the basal half, though these are reduced and simplified in some species. The aedeagus is typically long and very slender, with a basal bulb, though is shorter and broader in a few species.
The female genitalia show similar diversity to the valves of the males, particularly in the sterigma and the base of the long ductus bursae, and some species show modification of the seventh segment, where the sternite can be triangular or distally bilobed. The groundplan may approximate to that of Luceria. The corpus bursae is ovate, usually with a small, round signum invested with a few short spines.
The genus is probably diverse through the Indo-Australian tropics, with two species in Sri Lanka, and others undescribed from N.E. Himalaya, the Andamans and Philippines (Holloway, 1977). A group of five Hawaiian species appears to be related to the morphologically more uniform Holarctic fauna. Inoue (1979) described a morphologically more diverse series of five species from Japan. Fletcher (1961) described what he considered to be the first species from subSaharan Africa. The four Bornean species below have forewing facies typical of the genus. Two further ones (slides 20125, 20126), both montane, have facies of a similar type, but their male genitalia are atypical, and therefore they are not included.
The larvae of Palaearctic species (e.g. Bretherton et al., 1983) have lost the two anterior pairs of prolegs. The natural feeding habits are not clearly known; one British species has been reared in captivity on herb flowers, withered leaves of sallow, lettuce and runner bean tissue. Covell (1984) recorded a N. American species from bracket fungus.
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