Isodemis quadrata, Sun, Yinghui & Li, Houhun, 2011

Sun, Yinghui & Li, Houhun, 2011, Review of the genus Isodemis Diakonoff (Lepidoptera, Tortricidae) from China, with description of three new species, ZooKeys 77, pp. 51-64 : 58-59

Isodemis quadrata sp. n. Figs 6-71519

Type material.

Holotype ♂ - China, Xizang (Tibet) Autonomous Region: Hanmi, Medog County (29°13'N, 95°18'E), 2380 m, 9.VIII.2003, coll. Xinpu Wang and Huaijun Xue, genitalia slide no. WXP03332. Paratypes: 1 ♂, 2 ♀♀, same data as for holotype.

Diagnosis.

The male is similar to Isodemis illiberalis superficially, but can be separated by the median fascia extending from the costal margin to the dorsum, the subapical blotch reaching across 1/3 width of wing and the quadrate uncus. In Isodemis illiberalis , the median fascia extends from the lower edge of costal fold to the dorsum, the subapical blotch reaches the tornus, and the uncus broadens from the basal 1/3 to the apex. The female genitalia are close to those of Isodemis stenotera , but can be distinguished by the ductus bursae being longer than the corpus bursae and the signum without tiny spines on its ventral surface; in Isodemis stenotera , the ductus bursae is about the same length as the corpus bursae and the signum consists of tiny spines on its ventral surface. In addition, the female can be easily separated from Isodemis stenotera by the ground color being yellowish brown mixed with ochreous, the median fascia extending from the costal margin to distal 1/3 of the dorsum, and the subapical blotch nearly inverted triangular; in Isodemis stenotera , the ground color is yellow with scattered pale ochreous scales, the median fascia reaches the middle of termen and is interrupted or indistinct medially, and the subapical blotch is narrowly stripe-shaped.

Description. Adult: Male (Fig. 6) wingspan 19.5-20.0 mm. Head, antenna and labial palpus yellowish brown, with scattered ochreous brown. Thorax and tegula ochreous brown mixed with yellowish brown. Forewing yellowish brown with sparse ochreous scales; costal fold tinged with brownish black, about 3/5 length of costal margin; markings brownish black mottled with ochreous: median fascia extending from costal margin to distal 1/3 of dorsum, slightly interrupted near costal fold, with a large rounded gray patch present on its outer side posteriorly; short stripe from basal 1/3 of dorsum extending anteriorly and joining inner side of median fascia at anterior 1/3, forming an irregular semicircular pattern above dorsum, leaving a rounded subtriangular patch of groundcolour at middle of dorsum; subapical blotch inverted triangular, extending from distal 1/3 of costal margin to before apex, reaching across 1/3 width of wing; cilia yellowish brown. Hindwing dark gray, distally with a pale grayish brown patch tinged with yellowish brown; cilia dark gray. Legs dark yellow, tinged with brownish black on ventral side of foreleg and on outer side of mid- and hindlegs. Abdomen grayish brown.

Female (Fig. 7) wingspan 21.0-22.5 mm. Head and labial palpus dark grayish brown. Antenna brownish black tinged with yellowish brown. Forewing broader than in male, nearly rectangular, apex slightly protruding anteriorly; costal margin tinged with brownish black; posterior 4/5 of median fascia ochreous brown with sparse brownish black scales; lower edge of subapical blotch slightly rounded; with small diffused patch placed near middle of termen. Hindwing gray, anterodistally with a yellowish brown patch mottled with brownish black.

Male genitalia

(Fig. 15). Tegumen developed. Uncus nearly quadrate, straight on posterior margin. Gnathos arm slender and long; terminal plate nearly triangular, about 1/3 length of arm. Valva with length about 1.5 times width, rounded terminally; transtilla spine-shaped, disconnected medially. Sacculus weakly sclerotized; terminal process nearly thumblike, reaching plica. Vinculum somewhat concave at middle on anterior margin, with two small spines near middle of anterior margin. Juxta approximately oval, slightly concave at middle anteriorly. Phallus slightly longer than length of valva, straight, dilated basally, with ten deciduous cornuti and a single non-deciduous cornutus that is about 1/3 length of phallus.

Female genitalia

(Fig. 19). Papilla analis narrow and long. Apophysis anterioris slightly longer than apophysis posterioris. Sterigma inverted subtriangular. Antrum short, with inner sclerite anteriorly; ductus seminalis coming from anterior margin of antrum; ductus bursae longer than corpus bursae, curved perpendicularly at posterior 1/3; cestum placed between posterior 1/3 of ductus bursae and anterior margin of antrum. Corpus bursae rounded; signum horn-shaped, dentate marginally, its globular process about 1/3 length of signum.

Distribution.

China (Tibet).

Etymology.

The specific name is from the Latin quadratus (= square), referring to the rectangular uncus in the male genitalia.