decrescens Walker, Sri Lanka.
Synonym: Cryptothripa Hampson (type species
occulta Swinhoe, India), syn. Ochrothripa Hampson (type species
leptochroma Turner, Australia) may also be
referable (see below).
This genus is available for a number of species previously assigned to
Gadirtha that have distinctive features of the male genitalia such as more
elongate, entire valves and striking development of what appear to be socii on
the uncus, bearing dark spines at their apex. The uncus is relatively long and
slender, sometimes apically bilobed or bifid. The tegumen is also more elongate
and, in the type species of Cryptothripa and an undescribed species from
Java and Bali (slide 16865), has slender, sinuous, digitate processes on each
side, and there are shorter, broader ones in the type species of Plotheia.
Semper the tegumen is distinctly broadened on each side but lacks processes. The
aedeagus is simply curved, the vesica rather globular, and there may be
development of a juxta.
The female genitalia have a short, sclerotised ductus and often a very elongate
bursa within which the paired, spined bands are elongate and rather weak or
absent. The bursa may have a small, spherical appendix, separated by a narrow
The species are generally smaller than those in Gadirtha and have a
distinctive greenish forewing facies with a paler apical patch similar to that
of Arachnognatha in the Ariolicini.
As well as the species noted above and below, the genus also includes
Hampson comb. n. (New Guinea),
Prout comb. n. (New Guinea) and probably
Fletcher comb. n. (Solomons: Rennell I.). The South African species,
Hampson, has female genitalia typical of the Iscadia group, but more
robust than in Oriental species. Two Australian species may also be referable to
Plotheia, but no males were available for examination:
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