Synopsia Hübner, 1825

Type species: Geometra sociaria Hübner, 1799 [Europe].

Synopsia Hübner, [1825] 1816 . Verzeichnis bekannter Schmetterlinge, 317.

Synopsidia Djakonov, 1935 . Lambillionea 35, 147. Type species: Synopsia znojkoi Djakonov, 1935 . Herewith regarded as new synonym of Synopsia based on morphological examination (see below).

Taxonomic remark. Synopsidia has been described as subgenus of Synopsia referring to the absence of a proboscis (which is also rudimentarily developed in Synopsia (see figs 1 A–D)), a simplified wing pattern, a blunter and broader uncus, as well as a smaller number of cornuti on the vesica (Djakonov 1935). Also, within the diagnosis of Synopsidia (see Djakonov 1935), all characters and similarities with Synopsia were stated (e.g., the congruent wing venation (fig. 3) and details of the genitalia structures). Later, Synopsidia was raised to genus rank referring only to the absence of the proboscis (Brandt 1938, Wehrli 1954). Our investigation supports the view that Synopsidia needs to be regarded as a new synonym of Synopsia based on similar morphology (see diagnosis).

Description and diagnosis. Wings and body. Medium-sized moths (wingspan between 26–44 mm). Antennae bipectinate in males, filiform or bipectinate in females (if bipectinate, length of branches from 0.1 mm to 0.48 mm) (figs 1–2). Proboscis reduced or represented by barely visible rudimentary slats (Djakonov 1935) (see fig. 1 A–D). Wings brown with light grey areas, bright beige or white to darker yellow with some brown spots (wings white with dark brown veins in Siona; wings light yellow, strongly intermixed with brown in Hypoxystis; varying combinations of yellow and orange in Angerona; varying shades of brown in Phthonandria; golden brown-yellow in Chariaspilates) (figs. 5–26; see Skou & Sihvonen 2015, pages 487, 495, 499 & Müller et al. 2019, page 587). Frons, thorax and abdomen concolorous with wings. Chaetosemata developed as two small separate patches.

Venation (figs 3–4). In the forewing Sc and R1 arising from a common stalk (similar condition in Hypoxystis, Angerona, Phthonandria and Chariaspilates; Sc arising separately from the wing base and continuing to the costal margin of the wing, R1 free, originating from the cell in Siona). In Synopsia R2 arising on a separate stalk; in its second half shortly anastomosing with common stalk of R3 and R4, (similar condition in Chariaspilates; Phthonandria; Angerona; Hypoxystis; R2 touching the common stalk of R3 and R4 without anastomosis in Siona) (fig. 4). R3–5 arising from a common stalk originating from the cell. R3–4 on common stalk distally of origin of R5. In the hindwing Sc+R1 fused, strongly curved in basal area, anastomosing with Rs and with vein M2 reduced.

Male genitalia (figs 27–36; Skou & Sihvonen 2015, pages 529, 537, 543 & Müller et al. 2019, page 651). Uncus strongly sclerotized and slightly to strongly bifurcate, sometimes tip only concave in the centre (uncus absent in Siona; short and stout in Hypoxystis; as a shallow plate in Angerona; small and bifid in Phthonandria; tapering in Chariaspilates). Gnathos strongly sclerotized, upturned, tongue-shaped, width of tongue differing (upturned and tapered in Siona; plate-shaped in Hypoxystis; upturned and tapered in Angerona; large and upturned in Phthonandria; as a large medial plate in Chariaspilates). Costa of valva with projection at the centre (similar condition in Hypoxystis and Chariaspilates; basal projection in Siona, Angerona and Phthonandria).

Costal projection bearing one or more spines (only one spine in Siona; spines absent in Hypoxystis; spinose in Angerona; bearing spines in Phthonandria and Chariaspilates). Saccus wide and round, sometimes with extensions (without extensions in Siona, Hypoxystis, Angerona, Phthonandria and Chariaspilates).

Aedeagus with several strongly sclerotized cornuti on the vesica (a small row in Siona; small and dentate in Hypoxystis; one cornutus in Angerona; cornuti variable in number in Phthonandria; patch of microcornuti in Chariaspilates) (fig. 36).

Female genitalia (figs 37–40; Skou & Sihvonen 2015, pages 571, 579, 585; Müller et al. 2019, page 716). Ductus bursae sclerotized (short, laterally sclerotized in Siona; membranous short and wide in Hypoxystis and Angerona; short in Phthonandria and Chariaspilates). Corpus bursae anteriorly membranous (anterior part membranous in Siona; large and membranous in Hypoxystis and Phthonandria; anteriorly elongated in Angerona; anteriorly subtriangular in Chariaspilates). Signum present, serrated (elongated, with dentate margins in Siona; rectangular in Hypoxystis; rectangular with hollow centre in Angerona; oval with hollow centre in Phthonandria; elongated with sclerotized margins in Chariaspilates).