Metaeuchromius singulispinalis Li & Li

Li, Weichun, Li, Houhun & Nuss, Matthias, 2009, Notes on the genus Metaeuchromius Bleszynski (Lepidoptera: Crambidae: Crambinae) from China, with description of two new species, Zootaxa 2287, pp. 55-63 : 57-59

Metaeuchromius singulispinalis Li & Li , sp. nov.

( Figs. 1 , 5–8 )

Type material. Holotype 3, CHINA: Chenjiashan, Daozhen (28°53´N, 107°36´E), Guizhou Province, 1300 m, 19.viii.2004, leg. Yunli Xiao, genitalia slide No. LWC07386. Paratypes: 2 ♀♀, same data as holotype; 1 ♀, Dashahe, Daozhen, Guizhou Province, 1350 m, 24.viii.2004, leg. Yunli Xiao; 1 ♀, Huguosi, Fanjingshan (27°55´N, 108°41´E), Guizhou Province, 1300 m, 1.viii.2001, leg. Houhun Li and Xinpu Wang.

Diagnosis. This species is similar to Metaeuchromius changensis Schouten in appearance, and in the male genitalia by the valva ending with a long spine, but can be distinguished from it by the symmetrical valvae and the phallus bearing a single strong spinelike cornutus. Whereas in M. changensis Schouten , the valvae are asymmetrical and the phallus carries a group of long and thin needlelike cornuti. This species also resembles M. yuennanensis (Caradja) in appearance and in the male genitalia, but can be separated by the straight medial fascia of forewing, symmetrical valvae and single cornutus in the male genitalia, and by the unsplited ductus bursae in the female genitalia. While in M. yuennanensis (Caradja) , the medial fascia is more or less incurved, the valvae are asymmetrical, the phallus bears a group of long and thin needlelike cornuti, and the ductus bursae is split into two parts.

Description. Adult ( Fig. 1 ): Wingspan 14.0–15.0 mm. Frons white. Vertex white to yellowish white. Labial palpus about twice length of eye’s diameter, yellowish white to pale yellow except yellowish brown to brown distally. Maxillary palpus pale brown, white basally and distally. Antenna scapus white; flagellomere with dorsal surface pale yellow and brown alternately, ventral surface yellow ciliated with white. Patagium yellowish white to pale brown. Thorax white to pale brown on dorsal surface, glossy white on ventral surface. Tegula pale yellow to pale brown, inner margin white, posterior margin with long and thin white scales. Forewing sparsely suffused with pale brown to blackish brown scales; costa with longitudinal pale brown stripe extending from base to near medial fascia; medial fascia straight, running to about middle of dorsum, golden, edged with pale brown; discoidal cell with two short blackish brown stripes at about two thirds; apex with two oblique golden stripes, inner stripe lined with brown on both sides, between two golden stripes situated white stripe; subterminal line pale brown; seven terminal black dots running from middle of termen to tornus, fomula 2-3-2, each group divided by white, each dot of group divided by golden; cilia shiny, pale brown to blackish brown. Hindwing ground colour white, suffused with pale brown scales, with pale brown spot at basal 1/3 near costa; subterminal fascia absent; cilia yellowish white to pale brown. Legs white to yellowish white, slightly suffused with pale brown on outer side; tarsi with blackish brown rings.

Abdomen ( Fig. 5 ). Scent organ incorporated in male sternite III, oblong, opening towards outer side; wall of scent organ with pits, a cluster of slender scales attached to pits on outboard tip.

Male genitalia ( Figs. 6–7 ). Uncus slender, curved downward, tapering to blunt apex. Gnathos curved upward slightly, rounded distally. Tegumen nearly as long as gnathos. Valva narrow triangular, broad basally, tapering to apex; distal one fourth spinelike. Juxta with basal one third oblong, distal two thirds narrowed slightly, nearly rectangular. Pseudosaccus developed, elongate ovate, a bit smaller than juxta, rounded anteriorly, pointed posteriorly. Saccus developed, slightly shorter than uncus, rounded anteriorly. Phallus with distal part slightly thin and curved; cornutus strong spinelike, about one fourth length of phallus.

Female genitalia ( Fig. 8 ). Anal papilla ovate, about half length of apophyses posteriores, notched caudally. Tergite VIII nearly as long as apophyses anteriores. Apophyses anteriores about three fourths length of apophyses posteriores. Antrum tubular, straight, strongly sclerotized, its diameter about two thirds that of ductus bursae, covered with tiny spines anteriorly. Ductus bursae straight, posteriorly with wrinkled and sclerotized ovate protuberance, clothed with spines, its diameter a bit greater than that of ductus bursae. Ductus seminalis arising from medial part of ductus bursae, thick, basal diameter one third that of ductus bursae. Corpus bursae oval, laterally with granules, about half length and twice width of ductus bursae; signum absent.

Distribution. China (Guizhou).

Etymology. The specific name is derived from the Latin prefix singul- = singular and the word spinalis = spinose, in reference to phallus with a single spinelike cornutus.

Figures

FIGURES 1 – 4. Adults of Metaeuchromius spp.; 1, M. singulispinalis sp. nov., paratype, female; 2, M. anacanthus sp. nov., holotype, male; 3, M. inflatus Schouten, male; 4, M. flavofascialis Park, female.

FIGURES 5 – 8. Metaeuchromius singulispinalis sp. nov. 5, Abdominal scent organ of sternite III; 6, Male genitalia; 7, Phallus (5 – 7, genitalia slide No. LWC 07386, holotype); 8, Female genitalia, paratype (genitalia slide No. LWC 07445).