Trisula Moore
Type species: variegata Moore, India.
Kobes (1992)
summarised the history of the classification of the genus Trisula,
currently residing in the Pantheinae on grounds of a reduced counter tympanal hood,
the characters of the larva and the displaced position of the base of vein M2
in the quadrifine array of the hindwing. The family‑group name Trisulini
was published by Wiltshire (1990) without diagnosis and is therefore invalid
(Speidel & Naumann, 2005). The clypeofrons appears to be scaled, and the
abdominal features also suggest this may be a basal member of the ‘trifine’
clade. Hacker & Zilli (2007) have suggested that the genus may be a member
of their new subfamily Thiacidinae (see also p. 5). They indicated that the
position of this group within the Noctuidae s.l. was enigmatic, with it
showing features associated with both trifine and quadrifine clades. The
counter‑tympanal hood is unusually prespiracular.
The wing facies
is generally as illustrated for the Bornean species and resembles that of some
of the larger pantheines noted for Sumatra by Kobes (1985), though the
hindwings are duller and have a diffusely darker border and discal spot, the
latter more clearly defined on the underside. There is a black bar on the
forewing that cuts off the apex, running from the costa at two thirds to the
centre of the distal margin, and is just exterior to the postmedial from the
costa to where the postmedial curves round basad. The male antennae are strongly
fasciculate, and the labial palps are upcurved, with a short third segment.
The male abdomen
lacks a pair of lobes in the diaphragma between the first and second tergites,
and the eighth segment is unmodified apart from very short, broad apodemes on
both tergite and sternite. The genitalia have the uncus strongly hooked,
opposed by a scaphium. The inner margin of the tegumen is characteristically
concave ventral to an obtuse central angle. There does not appear to be a
paratergal sclerite. The valve is simple, narrow, though expanded subapically,
and has a harpe that is more of the ‘basal trifine’ type, though semi‑detached
from the rather square basal portion of the sacculus. The juxta is a pentagonal
plate. The aedeagus vesica is elongate, tapering, with two or three small lobes
basally.
In the female,
the ostium is situated between the seventh and eighth segments. The basal third
of the ductus is sclerotised and scrolled on each side. The distal third is
corrugate, membranous and scobinate, expanding slightly to join the corpus
bursae slightly subbasally, the basal lobe giving rise to the ductus seminalis.
The bursa expands from this point in a slightly pyriform fashion, but curves
distally such that the apex is directed laterally to the main axis. The bursa
is finely corrugate and scobinate throughout.
The genus contains two described
species as discussed below.
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