FAMILY LIMACODIDAE
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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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