Cyana bianca (Walker, 1856)

Volynkin, Anton V., Černý, Karel & Ivanova, Maria S., 2018, A review of the Cyana bianca (Walker, 1856) species-group with descriptions of a new species and a new subspecies from Indochina (Lepidoptera, Erebidae, Arctiinae), Zootaxa 4497 (1) : -

The Cyana bianca species-group

Diagnosis. The species-group is similar to the Cyana insularis ( Draudt, 1914) species-group partly reviewed by Lourens (2017). The pattern of both sexes is similar to that of members of the C. insularis species-group, but moths of the C. bianca species-group are larger, and in males the posterior black spot of the cell is streak-shaped (while in the C. bianca species-group it is rounded). The male genitalia of the C. bianca species-group differ from those of the C. insularis species-group in the presence of ampulla (absent in the C. insularis species-group), the more robust distal saccular process with a short thorn-like tip (while in the C. insularis species-group the distal saccular process is weaker distally and has a long thorn-like tip), the presence of the lateral lobes of the vinculum (absent in the C. insularis species-group), and the vesica armed with broad fields of short, but robust cornuti (while in the C. insularis species-group two or three narrow diverticula of the vesica are armed with dense clusters of long, spikelike cornuti). The female genitalia of the C. bianca species-group differ from those of the C. insularis speciesgroup in the presence of the posterior sclerotized plate of the corpus bursae and the absence of a rugose sclerotization of the anterior section of the ductus bursae.

Description. External morphology of adults. Length of forewing 14.5–19 mm in males and 19–21 mm in females. The sexual dimorphism well expressed: males smaller than females, have narrower forewings with androconial lobes on underside, and three black spots in cell, whereas females have broader forewings without androconial pockets and with only two black dots in cell. Antennae ciliate in both sexes. Head white. Thorax white, with broad red bands on tegulae and patagia margins, and red transverse bands on medial and posterior parts. Abdomen whitish with numerous pale red scales. Forewing ground color white. Subbasal line red, wavy; antemedial line broad, red, its outer margin slightly wavy and bordered by thin black line; postmedial line broad, slightly S-like curved, its outer margin bordered by thin black line; terminal line red, with diffuse inner margin; in males there is short black streak connecting costa and outer black margin of postmedial line; three black round spots of different size in cell in males and two large black round spots in females; cilia whitish. Hindwings pale red, without pattern, slightly lightened along costal margin; cilia pale red. Male genitalia. Uncus elongated, slender, distally narrowed, apically tapered, basally connected with scaphium. Anal tube broad, scaphium broad, membranous; subscaphium broad, weakly sclerotized, setose. Tegumen of moderate length, narrow; vinculum short, broad, U-like, with lateral lobes; juxta trapezoidal, with broadly trigonal bottom concavity. Valve lobe-like, with strongly curved costal margin, distally narrowed, apically rounded; sacculus broad, moderately sclerotized; distal saccular process long, robust, curved dorsally, with spine-like tip, well separated from distal part of valve, its tip almost reaches valve apex; ventral plate of costa short, narrow, with well-developed ampulla directed ventrally. Aedeagus long and broad. Vesica broad, consists of four largest diverticula with small subdiverticula; medial posterior and distal diverticula covered with numerous small cornuti; medial anterior diverticulum granulated or with setose scobination; medial dorsal diverticulum with four small subdiverticula, granulated; vesica ejaculatorius broad, projected ventrally. Female genitalia. Ovipositor short and broad. Papillae anales rectangular with rounded angles; apophyses thin, apophyses anteriores of equal length or slightly shorter than apophyses posteriores; ostium bursae broad, antrum broad, funnel-like, weakly sclerotized; ductus bursae moderately broad, membranous, slightly rugose; corpus bursae sack-like, with broad sclerotized area posteriorly, medial lateral sclerotized band and two-three signa anteriorly; appendix bursae broadly conical, membranous, situated dorso-posteriorly.