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Darna
Walker
Type species: plana Walker, a junior subjective synonym of metaleuca
Walker.
This genus, containing many species of economic importance, is here
treated in a broad sense, defined by Darna-type venation (Fig 38), male antennae bipectinate to the apex, and male genitalia with either
or both the following apomorphies: a divided uncus bearing distinctive rows of
dark scales on the ventral surface of each portion; a process from the basal
region of the valve costal area. The larva is generally of a rather humped (at
around Al) form, also seen in Trichogyia to an extreme, and is
characterised by small blade-like structures on the lateral scoli of A2 and A7 (M.J.W.
Cock, pers. comm.).
Darna metaleuca
Within this broad generic definition a number of other generic names
become incorporated as subgenera:
Subgenus Ploneta Snellen stat. n.
Type species: diducta Snellen.
Sexual dimorphism is extreme, females tending to have uniform brown forewings
and the smaller males having a fine, paler submarginal on generally darker
ground. The males of the type species have the forewing venation distorted by an
infolding of the margin, an autapomorphy.
In the male genitalia the uncus and gnathus are more or less fused together, the
dark scales reduced or lost. The Sundanian trio (diducta Snellen, flavina
Hering and bradleyi sp. n.) have prominent socii from the tegumen.
The costal process to the valve is not as sclerotised as in other subgenera,
more cylindrical than flattened, and runs dorsal to the costa rather than down
across the interior face of the valve.
The female genitalia have the ductus straight, relatively short. The bursa
contains a narrow, transverse, slightly bilobed signum in diducta and an
undescribed Indian species (slide 733) but is immaculate in bradleyi and jasea
Swinhoe.
The larva of P. diducta is described in the specific account. The larva
of one of the Indian group, jasea Swinhoe, was described by Bell (MS) but
misidentified as Natada (Parasa?) unicolor Moore, a species that should
be transferred to Aphendala, comb. n. It is slug-like, wood-louse
shaped, T1 pale orange with a shining blackish diamond shaped depression
anteriorly, dorsally, that is bisected by a thin white line. The lateral
tubercles are even in length (1.5mm), directed out from the margin horizontally,
and perpendicularly to the surface of origin. Those on T3, A2 and A7 are lilac
and those in between translucent green as is the area surrounding them; the rest
are colourless. The dorsolaterals are complete, shorter than the laterals, those
from A3 to A6 little apricot yellow buttons with lilac spines, the rest
colourless, somewhat longer. The ground colour is light violet, sometimes veined
with white, with a lateral semicircular green patch from A3 to A6 that reaches
the dorsolateral tubercle on A5. There is a thin white dorsal line traversed by
thin white lines across each segment before and behind the tubercle bases; these
excluded from the green semicircle. Bell noted variations of this theme. The
host-plant was not given. This description matches those for diducta and bradleyi
closely.
Subgenus Oxyplax
Hampson stat. n.
Type species: ochracea Moore.
The species have brown forewings, often tinged yellowish or golden, with an
oblique white or dark submarginal/postmedial fascia. There is little sexual
dimorphism.
The male genitalia have the processes of the bifid uncus and the gnathus robust,
the former well endowed with the rows of dark scales. The valve process arises
subcostally and extends obliquely downwards, simple, tapering, slender,
straight, over the interior face of the valve. The most widespread species, pallivitta
Moore, lacks the process, the only Darna to do so.
In the female genitalia (ochracea examined) the ductus is straight and
the bursa immaculate.
The only larva described is that of pallivitta (Piepers & Snellen,
1900), mentioned in the specific account.
Subgenus Darna Walker
There is little sexual dimorphism, the three species being at least
partly pale dull orange or pinkish orange.
The definitive features are in the male genitalia: the gnathus is very slender,
fused over almost its entire length; the uncus processes are delicate,
balloon-shaped, and thickly invested with rows of scales. The process from the
valve costa is a single flexed spine in nararia Moore but broader, of
even width throughout and with an apical patch of setae in the other two
species.
In the female genitalia (metaleuca) the ductus bursae is very short, the
bursa somewhat pyriform, the signum a single subapical spine. The ostium is set
in a V-shaped groove in the lamella postvaginalis, which is invested broadly
with fine, short setae.
The larva of metaleuca is described in the specific account. That of nararia
has been described by Horsfield & Moore (1850), Austin (1931-2),
Sevastopulo (1939, as suffusa) and Bell (MS). Only Bell described early
instars which are somewhat different from the mature larva. The mature larva is
green with the dorsum maroon, fluctuating in width with a broad portion on the
thoracic segments, narrowing on A4; there is an hour-glass shaped maroon band
over A6-8. There is a thin white dorsal line and similar dorsolateral ones.
Horsfield & Moore's description of N. Indian material omits mention of this
maroon band, but the adults show great variability and no doubt the larvae do
also. The dorsolaterals are reduced to hemispherical buttons, though those of T3
and A8 are slightly larger, those on T2 the same size as the laterals and those
of A9 somewhat longer. The laterals of T3 and all four processes of T2 are flesh
pink to red; the rest of the laterals green; the laterals on T2 are longer than
the rest and directed sideways.
The egg stage lasts six days, the larval stage five weeks and the pupal stage 14
days (Bell). The host-plants noted in the four accounts were Careya (Barringtoniaceae),
Crescentia (Bignoniaceae), Lagerstroemia (Lythraceae), Terminalia
(Combretaceae), Ziziphus (Rhamnaceae), Eucalyptus (Myrtaceae) Gliricidia,
Tephrosia, Erythrina, Crotalaria (Leguminosae), Citrus (Rutaceae), Ficus
(Moraceae), Cedrela (Meliaceae).
Subgenus Orthocraspeda Moore stat. n.
Type species: trima Moore.
Synonym: Thoseoides Shiraki (type species: fasciata Shiraki).
This group has species with similar facies to those of Darna (the
sordida pair) but the processes of the uncus are not balloon-shaped and
have lost the rows of scales ventrally. The valve processes arise from the very
base of the valve costa rather than being displaced distally as in typical Darna
and in Oxyplax.
The female genitalia have a pair of sclerotised plates on the lamella
vaginalis either side of the ostium. The signum in the bursa is variable but,
when present, is a scobinate zone or ridge set longitudinally within the bursa.
There are three species-groups.
The pair sordida
and bornesordida has a male forewing facies like a dark pinkish grey D.
metaleuca, though the female is more akin to Ploneta species in
pattern. In the male genitalia the saccus is angled, the valve process simple,
the uncus processes short, ventrally rugose, the gnathus also relatively short
and robust. The larva is described in the specific account.
The Sulawesi species catenatus Snellen has males and females with
a pale yellowish brown forewing, uniform apart from a regular dark marginal band
and a faint discal spot; the hindwings are dark grey-brown. The uncus is not
cleft to the base and the gnathus is rather slender though not as much or as
fused as in typical Darna. The valves have a slightly angled sacculus, a
stepped costa and a very long slender costal process that is longer than the
valves. The larva was described and illustrated by Kalshoven (1981). It is of Darna
shape though somewhat oblong, greenish with a violet or grey dorsal band
that contains a medium black stripe that is much more distinct in young larvae.
The rows of spined tubercles are complete, small, and uniform in size. The
host-plants recorded have been various palms, especially Cocos.
The remaining group contains the type species, one of five with rather
similar facies. The forewings are variably banded with dark grey, the bands
divided by narrow, transverse, almost black fasciae; sexual dimorphism is
slight, though females tend to have more variegated forewings than males. In the
male genitalia the uncus is usually deeply cleft, the processes long, without
scaling. The gnathus is bifid either apicallv or over a greater depth. The
costal process of the valve is also somewhat divided. The larva is typically
brownish red with white patches along the flanks, the posterior two pairs of
laterals being longer than the rest, and the dorsolaterals shorter than the
shortest laterals. A more detailed account will be found in the specific account
for trima.
The check-list of Darna species with synonymy is currently as
follows; with genus of original description in square brackets:
Ploneta
Darna [Ploneta] diducta Snellen comb. n. Sundaland.
Darna [Macroplectra] flavina Hering comb. n. Sumbawa.
Darna bradleyi sp. n. Borneo.
Darna [Thosea] cotesi Swinhoe comb. n. N.E. Himalaya.
Darna [Thosea] jasea Swinhoe comb. n. S. India ?t. loc.
Darna sp.
slides 902 ( ),
733 ( ).
N.E. Himalaya.
Oxyplax
Darna [Aphendala] ochracea Moore comb. n. India, Sri Lanka.
Darna [Natada] fulvidorsia Hampson comb. n. Sri Lanka.
Darna [Natada] fulvimixta Hampson comb. n. Sri Lanka.
Darna sp.,
Slide 729 ().
Peninsular Malaysia.
Darna [Miresa] pallivitta Moore comb. n. China, Taiwan, Sundaland.
Darna
Darna metaleuca Walker.
Sundaland
= plana Walker
Darna [Thosea]
sybilla Swinhoe
comb. n. Thailand.
Darna [Parasa]
nararia Moore
comb. n. India, Sri Lanka
= suffusa Moore [Susica]
= signata Moore [Susica]
= fraterna Moore [Susica]
= cosmiana Swinhoe [Susica]
= sericea Hampson [Susica] syn. n.
Orthocraspeda
Darna
[Birthama] senescens West
comb. n. Philippines.
Darna [Limacodes]
catenatus Snellen. Sulawesi, Sangihe.
Darna [Orthocraspeda]
sordida Snellen. Thailand, Peninsular Malaysia, Sumatra, Java.
= luticrista Tams
syn. n.
Darna
bornesordida sp.
n. Borneo.
Darna [Orthocraspeda]
trima trima Moore. Java.
trima ajavana ssp. n. Borneo, Sumatra, Peninsular Malaysia.
Darna [Natada]
tuaranensis Holloway comb. n. Borneo.
Darna [Natada]
furva Wileman comb. n. Taiwan, China, N.E. Himalaya, Thailand
= fasciata Shiraki [Thoseoides] syn.
n.
Darna sp.
slides 422, 811, 837 ().
Philippines: Mindanao.
Darna sp.
slides 931, 932. Philippines: Luzon.
A tentative scheme of relationships within Darna is shown in Fig. 41
below. The
numbered spots on the stalks represent presumed apomorphies as follows:
1. A process from the base of the valve costa and/or rows of non-deciduous
scales on a bifid uncus. Larva with blades on laterals of A2 and A7.
2. Strong sexual dimorphism. Uncus and gnathus fused, with scales reduced or
absent. Process on valve costa arises from costal margin, held dorsally to the
valve, and cylindrical rather than blade-like, (the sub-costal position and
extent outwardly and ventrally across the anterior face of the valve is presumed
plesiomorphic; if apomorphic it would place Ploneta as sister-group to
the rest, defined by it; larval characters, such as a fine white reticulate
pattern, may indicate Ploneta and Oxyplax to be sister-groups).
Figure
41.
Cladogram for the genus Darna indicating the subgenera recognised.
Numbers instead of species at the branch ends refer to BM genitalia slide
numbers of specimens belonging to undescribed species. The groupings within the
cladogram are defined by apomorphies listed in the text under the numbers on the
diagram. Distributions of the species are indicated by the following
abbreviations: B. Borneo; C, China; IN, India; J, Java; M, Peninsular Malaysia;
NEH, N.E. Himalaya; N.IN, North India; PH, Philippines; SL, Sri Lanka; S.IN,
South India; SUL, Sulawesi; SUMB, Sumbawa; SUN, Sundaland; TH, Thailand.
3. Uncus and gnathus reduced. A pair of prominent socii on the tegumen.
4. Tegumen broad. Gnathus darkly sclerotised and concave dorsally. Socii set
well apart but incurved towards uncus.
5. Sexual dimorphism weak with facies consisting of an oblique postmedial/submarginal,
usually white, on bronzy brown forewings.
6. Process from valve costa an elongate, simple triangle, (absent in pallivitta).
Species robust.
7. Forewing discal spot present. Forewing with dark submarginal parallel to
margin, though present only as a dark bar at the costa in some species. Oblique
postmedial absent (if presence is apomorphic then Ploneta and Oxyplax are
sister-groups, then sister to Darna and Orthocraspeda)
8. Gnathus very slender, fused over almost entire length. Uncal processes
scaled, balloon-like. Facies of forewing pale dull orange with paler triangle.
9. Costal process of valve broad, apically setose.
10. Signum of bursa longitudinal when present (transverse in Ploneta, a
single spine in Darna metaleuca). Ostium bursae flanked by two
sclerotised flaps on the lamella vaginalis. Scales on uncus processes reduced to
small knobs or lost. Costal process of valve crosses down over its interior
surface but arises basally rather than subbasally.
11. Forewings dark pinkish grey in male, markings typical of Darna + Orthocraspeda
group; females more as in Ploneta species. Sacculus strongly produced
and angled. Costal processes of valve single, tapering gently to a point.
12. Grey forewings with several dark transverse fasciae. Scales on uncus
completely absent (rugose areas present in sister group).
13. Gnathus more or less bifid. Costal process of valve more or less divided.
14. Gnathus deeply cleft. Costal process of valve completely divided.
15. Processes of gnathus long and slender. Uncus processes set on triangular
basal portion (absent in other species of genus). Longer costal process of valve
flexed twice rather than once.
The Luzon species of the trima group was found after the cladogram was
drawn up but is sister to that from Mindanao, sharing modification to the
gnathus and production of the posterior lamella of the sacculus into a dorsally
directed rod.
The Philippines species Birthama senescens West is misplaced in that
genus, and examination of the male genitalia suggests that it belongs to the Orthocraspeda
group of Darna, comb. n. Females are unknown so its location on the
cladogram is uncertain; it may be best considered as a fourth group of the
subgenus.
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