Digonis Butler, 1882

Ramos-González, Mario I., Venegas-González, María Francisca, Zamora-Manzur, Carlos & Parra, Luis E., 2024, Revision of the genus Digonis (Lepidoptera, Geometridae): new species and new genera, ZooKeys 1216, pp. 173-200 : 173-200

Digonis Butler, 1882

Digonis Butler, 1882: 360; Bartlett-Calvert 1886: 333; Angulo and Casanueva 1981: 12; Scoble 1999: 229; Pitkin 2002: 248.

Type species.

Digonis aspersa Butler, 1882 . By original designation.

Diagnosis.

Digonis resembles Digonodes Warren, 1895 , Gonogala Butler, 1882 , and the newly proposed genus Phasmadigonis gen. nov. particularly due to the mucronate shape of the wings. However, it is distinguished from Digonodes by the presence of a mucronate outer margin on the M 3 of the hindwings and the presence of filiform (not bipectinate) antennae. It is recognized as distinct from Gonogala by the absence of bipectinate antennae and M 2 in the hindwings. It differs from Phasmadigonis by the presence of two accessory areoles in the forewings, R 2 arising from R 3 + 4, and the absence of a vein connecting Sc + R 1 to the discal cell in the hindwings. The monophyly of Digonis is supported by the following genital characters: a U-shaped gnathos with a plate or a pair of denticulate lobes, a concave, sclerotized process on the costa with an extended cucullus, a furca armed with spines, an aedeagus without cornuti, and a strongly denticulate annular signum.

Redescription.

Antennae serrate in males and filiform in females. Thorax and abdomen with brown to grayish scales. Forewings castaneous yellowish, gray, brown, or coppery; costal margin in the apical area slightly arched; outer margin concave between apex and M 3 vein. Wing venation (Fig. 1 ). Two accessory cells; Sc in contact with first accessory cell, R 1 originates near apex of second accessory cell, R 2 + 3 + 4 from apex of second accessory cell, R 3 and R 4 stalked, R 5 terminates at termen; M 2 equidistant between M 1 and M 3, M 3 slightly arched and ending in small mucronate apex; CuA 1 originates 1 / 10 before end of cell, CuA 2 originates near the midpoint of the cell. Hindwings paler than forewings, with multiple dark brown scattered spots; medial band conspicuous or faint; outer margin slightly mucronate. Sc + R 1 in contact with radial stem up to middle of cell, Rs originates 1 / 10 before end of cell, M 2 absent. Male genitalia with conical uncus; gnathos “ U ” shaped, with a pair of prominences or a denticulated plate; subrectangular valvae with a strong sclerotized and concave costal process; spiny furca; aedeagus unarmed. Female genitalia with subpyriform corpus bursae, annular and strongly denticulated signum.

Distribution.

This genus is distributed between latitudes 30 ° S and 47 ° S, spanning the provinces from Elqui to Capitán Prat in Chile.

Figures

Figure 1. Wing venation of Digonis Butler, 1882. Scale bar: 10 mm.