Diagnosis of Deserticossus Yakovlev, 2006

Species of Deserticossus are of medium size, dark coloured. Antenna is not pectinate. Fringe of fore wing is mottled. Fore wing has dark undulated pattern, often with strokes in postdiscal area. Hind wing is unicolorous. Females of constituent species are larger than males, their colour in general similar to that of males. Fore wing is slightly wider than in males.

Male genitalia. Uncus is triangle-shaped, gnathos arms are thin, quite long; gnathos is of medium size, with undistinguished zone where the arms are fused. Valva is elongate, narrow, with distinct border between membranous and sclerotized part and a process on the costal edge. Transtilla processes are thick, uncinately bent, tapered at apices, with wide base. Juxta is small, rhomboid, with small lateral processes. Saccus is quite large, semicircular. Phallus is slightly curved, its distal aperture in dorso-apical position. Apex is slightly bent and tapered. Vesica does not contain cornuti.

Female genitalia. Ovipositor is long, with elongate, distally rounded papillae anales. Posterior apophyses are two times as long as apophyses anterior, ostium is surrounded by crescent-shaped sclerotized plate, antrum is cuplike, ductus bursae is membranous, bursa copulatrix is membranous, pouch-like, without signa. Ductus seminalis is incepted in basal part of bursa.

The diagnostically important features for the determination of the genus are the external characters, in particular the pattern on the fore wing, the form and size of the process on the costal edge of the valva, and the form of the phallus. Female genitalia do not have any diagnostic features.