Skip to main content

Eastern Asia moth (Dryadaula orientalis) from Japan is very similar to Dryadaula epischista Meyrick 1936

Dlium Eastern Asia moth (Dryadaula orientalis) from Japan is very similar to Dryadaula epischista Meyrick 1936

NEWS - Dryadaulidae is assigned to two genera, Dryadaula and Brachydoxa, based on molecular phylogenetic analysis, although both genera were formerly included in Tineidae. Three genera, Eschatotypa, Eugennaea and Sagephora, have been suggested to be included in Dryadaulidae based on asymmetrical male genitalia.

Dryadaula currently has 50 described species and has a pan-global distribution, 14 species in the Palearctic, 16 in the Neotropics, 1 in the Nearctic, 2 in the Afrotropics, 4 in Indomalaya, 12 in Australia, and 2 in Oceania, while Dryadaula pactorlia Meyrick 1901 has been recorded from New Zealand and Europe. Only 2 species are from Japan: D. epischista (Meyrick, 1936) and D. trapezoides (Meyrick, 1935).

The researchers conducted a field survey at the type site to determine the true genital morphology of D. epischista. During the study, they observed that "D. epischista" from Hong Kong did not represent true D. epischista and discovered another unknown species from Japan.

D. orientalis male has a forewing length of 3.0 mm, antenna length of 2.4 mm in holotype. Forewing length of 2.7–3.7 mm (N = 11); antenna length of 1.9–2.6 mm in paratypes (N = 9). Similar to D. epischista except forewing ground color varies from bright orange to dull brown.

Male genitalia, asymmetrical. Uncus elongated and weakly curved to tip, and weakly twisted at middle. Tegumen twisted to the left and slightly wider in the center, fused with vinculum. Vinculum narrowly arched; saccus equipped with an obtuse triangular lobe at middle. Gnathos absent.

Right and left valva clearly asymmetrical. Right valva flat; basal half with broad triangular lobe, protrusions varied from sharp to rounded; apical half densely covered with relatively long setae; basally with small setose curved rod-shaped projection. Left valve thick, but slimmer than right valve, tip paddle-like shaped, with lobate process; lobate process near apical part bearing spinose setae on dorsal surface.

Sternite VIII hollow and curved claw-like shaped; apical spine short and thick; ventral margin with two slender projections, basal projection longer than central projection. Juxta rounded triangle and connected to left valva and phallus.

Phallus asymmetrical elliptical with a curved, thick, and sharp spine apically; and with basal side of projection with or without a straight or curved thin projection; rounded projection attached to juxta; cornuti absent. Intersegmental membrane between seventh and eighth tergite with a pair of free sclerites laterally; right free sclerite broad U-shaped; left free sclerite V-shaped.

Females have a forewing length of 3.0–3.6 mm in paratypes (N = 7), Antenna length 2.2–2.3 mm in paratypes (N = 4). Almost all the same as male, but white spot of subapical part of costal margin narrowed and connected to white line of costal margin in female.

Female genitalia, sternite VIII covered with bristles, strongly sclerotized, right side markedly swollen posterolaterally; terminal swelling passing the ventral edge; ostium bursae opening the posterior end of swelling. Right side of “seventh segment” slightly bulged. Right side of “sixth segment” with posteriorly protruded bulge.

Median dent spherically and strongly concaves between right side of sixth and seventh segments. The analytical papillae are slim and short, the same length as the apophyses posterioris. Apophysis posterioris relatively short, slightly longer than eighth abdominal segment.

Ductus bursae and corpus bursae membranous. Ductus bursae thin tubular, 4× as long as apophysis posterioris. Corpus bursae elliptical, densely wrinkled from ductus bursae side to the end.

Coloration is similar to D. epischista, but the new species can be distinguished by characteristics of male and female genitalia. Male genitalia lack spines on left valve (vs. present in D. epischista); female genitalia have lateral abdominal swellings reaching the end of the abdomen on the eighth segment (vs. not reaching the end of the abdomen in D. epischista).

Adults were observed between May and September. Females lay flat eggs on dead leaves of monocotyledonous plants (Sasa sp.). The name of the new species is derived from the Latin ‘Orient’ (east) because of its restricted distribution in eastern Asia. The phallus, right valve and body coloration show geographic variation.

D. epischista and D. orientalis are within the clade that includes D. heindeli and D. terpsichorella, but the former two species differ in many characteristics, including narrow trapezoidal wings, a flat right valve, and a curved, twisted, and elongated uncus, whereas most species in this genus have broad trapezoidal hind wings.

Original research

Park J, Yagi S, Kobayashi S, Hirowatari T (2024). A new species of the genus Dryadaula Meyrick (Lepidoptera, Dryadaulidae) from Japan, with a redescription of D. epischista (Meyrick, 1936). ZooKeys 1217: 327-342, DOI:10.3897/zookeys.1217.122695

Dlium theDlium

Popular Posts

Fern tree (Filicium decipiens)

Kerai payung or fern tree ( Filicium decipiens ) is a plant species in Sapindaceae, a tree that is always green with thick and round canopies such as umbrellas, 5-10 m high but old specimens in nature can exceed 25 m, upright stems, gray bark ash to reddish brown, smooth when young but rough and cracked when mature. F. decipiens has large, fern-like and conspicuous leaves, up to 40 cm long and made of elongated longitudinal, glossy green leaflets arranged in pairs. Leaves on stems with a length of 3-10 cm, alternating, imparipinnat, 15-30 cm long and 12-15 cm wide. Winged rachis with 6-12 pairs of opposite or sub-opposite leaflets, sessile, oblong-lanceolate with full margins and slightly wavy, 6-12 cm long and 1-3 cm wide, coriaceous, dark green and glossy above. Flowers grow on stems with a length of 7 cm as panicles for lengths of 15-30 cm which carry many small, unisexual flowers and hermaphrodites with a diameter of 0.4-0.6 cm. Pentaparted petals with imbricate ovate lobes, fi...

Porang (Amorphophallus muelleri)

Porang or iles-iles ( Amorphophallus muelleri ) is a plant species in Araceae, the petiole is a pseudo stem with a height of 40-180 cm, 1-5 cm in diameter, round, green or purple with irregular white spots, each branching point grows brown bulbil and yellow bulb. A. muelleri has all leaves or stems or stems that are light green to dark green or gray and has greenish-white patches, smooth or smooth surface. The leaves are elliptical in shape with pointed leaf tips, smooth and wavy surface. When flushing has 3, 4-5, 5-6 and finally 6 minor leaves branching with 3 minor petioles. Young leaves have light purple or green edges and will end in yellow and 0.3-0.5 mm wide. The whole canopy is 50-150 cm wide. The stems grow above the tubers with a diameter of 25-50 mm and a height of 75-175 cm. Tubers have a brownish yellow or gray color on the outer surface and brownish yellow on the inside, are slightly oval in shape, fibrous roots, weigh 450-3350 grams, smooth tissue, 4-5 months of dormanc...

Golden-armed mantis (Hierodula venosa)

Golden-armed mantis ( Hierodula venosa ) is an animal species in the Mantidae, winged praying mantis with females 65-75 mm long and males 45-65 mm, large but not the largest in the genus Hierodula and generally bright yellow with green and chocolate variations. H. venosa has a fully rotating head. The head is dominated by a pair of very large and brownish yellow eyes. The jaw forms a triangle. The back is very wide with thickened margins. A pair of long antennas. Wide wings with rounded tips, striped surface, thick margins, two small white plots on the right and left. The belly is large and jointed, curved downward, the upper part is completely covered by the wings, but partially visible from the side. The pair of forelegs are large and have three segments. The upper segment has rows of spikes on the front and back. The middle segment has a row of many spines on the back and a black tip. The third segment has a row of many spines, long, black and tipped with a long palm. The middle ...