Type species: orientalis Westwood (Singapore, Peninsular
Synonym: Neocastnia Hampson (type species nicevillei Hampson,
This genus is the only Oriental representive of the Castniidae. The
three described species are virtually restricted to Sundaland, as the type
species of Neocastnia is only known from the Tenasserim region of Burma,
just north of Peninsular Malaysia. There is a fourth species, undescribed, with
the upperside entirely black, the forewing with an oblique white bar typical of
the genus, and the narrowly falcate apex as in the type species. It is
represented by a single specimen taken in Sumatra at Lebong Candis on a pass at
about 400m; the hindwings below are mainly rusty orange.
All four Tascina species have the oblique white bar to the
forewing narrow. The type species has the hindwing orange with a broad black
border as distinct from the blue iridescence in the Bornean species. The Bornean
species has only a weakly falcate forewing apex in the male, and the apex is
more rounded in the female. General characters of the genus are referred to in
the family account.
The male genitalia of the type species (Fig 6) and the Bornean species
differ from those in Castniinae in having a strong but undivided saccus and an
aedeagus that is straight, not reflexed. The uncus is broadly bilobed. The
valves are small, narrowly triangular. Unusual features are the great depth of
the vinculum, and fusion of the valves and gnathus closely around the anellus.
The female genitalia of the Bornean species have the ovipositor only
moderately extensile, though the lobes are acute, with long setae. The ductus
bursae is very long and slender, the corpus bursae twice as long as broad, the
two together extending the length of the abdomen. Unlike in most Neotropical
taxa, there is no signum or appendix bursae.
The Sumatran specimen has a note attached by C.J. Brooks, the collector,
stating that it resembled a skipper butterfly in flight and was originally
mistaken for such.
>>Forward <<Return to Contents page