Lythria (Lythria) Hubner 1823
Creators: name: Makhov, I. A.
name: Gorbunov, P. Yu.
name: Lukhtanov, V. A.
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Lepidoptera
Geometridae
Lythria

description: Lythria (Lythria) Hübner, [1823]
Type species. Phalaena purpuraria Linnaeus, 1758.
Diagnosis. In male, the vinculum is deeply concave ventrally, with the pointed dorso-distal corners; the valva bears a distal membranous part (valvula), the valva-genital segment articulation is flexible; the juxta and sclerotized anellus are absent; sclerotized tegumen is not developed; in female, the corpus bursae without signum.
Species included. L. (L.) cruentaria (Hufnagel, 1767); L. (L.) sanguinaria (Duponchel, 1842); L. (L.) purpuraria (Linnaeus, 1758) and L. (L.) plumularia (Freyer, 1831).
Identification key to Lythria species
Wing pattern:
1. Forewing pattern dark (dark brown or purple brown), contrasting with dark cream or beige ground colour, basal area markedly darkened........................................................................................... 2
– Ground colour of forewing yellowish orange to brownish yellow; pattern reddish, often with olive-grey scales, basal area barely darkened........................................................................................... 3
2. Hindwing without submarginal fascia; fringes of both wings dark brown, almost black (Pl. 1: 1a–1c)...... L. (M.) venustata
– Hindwing with dark submarginal fascia or its distinct trace reaching costal margin; fringes of both wings dark reddish (Pl. 2: 5a–5h)............................................................................... L. (L.) plumularia
3. Medial fascia of forewing commonly reduced to a costal spot, at equal distances from antemedial and postmedial fasciae, never fused with them (Pl. 2: 4a–4i)............................................................. L. (L.) purpuraria
– Medial fascia of forewing usually present, well developed, sometimes confluent with antemedial fascia................ 4
4. Postmedial fascia of forewing continuous; medial fascia of forewing usually closer to postmedial one or confluent with that; antemedial fascia commonly broad and reaches veins Cu 2 (occasionally transverse fasciae absent) (Pl. 1: 2a–2o)................................................................................................. L. (L.) cruentaria
– Postmedial fascia of forewing usually broken into a row of reddish dashes or spots on veins; medial fascia not fused with postmedial one; antemedial fascia often marked on costa only (Pl. 1: 3a–3d)....................... L. (L.) sanguinaria
Genitalia structure:
1. In male (Figs 7A–7F) valvae and genital segment articulated rigidly, distal membranous part of valva (valvula) absent, juxta well developed; in female (Fig. 8B) corpus bursae with rhombic lamellar signum...................... L. (M.) venustata
– In male valvae-genital segment articulation flexible, distal membranous part of valva (valvula) developed, juxta not developed; in female signum absent................................................................................ 2
2. In male vesica with a single cornutus, valva roughly rectangular, valvula long and narrow; in female lamella antevaginalis not developed, ductus bursae distinctly narrower than posterior part of corpus bursae................................... 3
– In male vesica with two cornuti, valva roughly triangular, valvula short, rounded sack-like; in female lamella antevaginalis well developed, sclerotized, ductus bursae equal in width with posterior part of corpus bursae or broader.................... 4
3. In male (Figs 7G–7I) coecum of aedeagus swollen, cornutus smaller than in L. sanguinaria; in female (Figs 8C, 8E) ductus bursae long, almost equal in length to broader posterior part of corpus bursae......................... L. (L.) cruentaria
– In male (Figs 7J–7L) coecum of aedeagus not swollen, cornutus longer and stouter than in L. cruentaria; in female (Fig. 8D) ductus bursae short, no longer than ½ length of broader posterior part of corpus bursae............... L. (L.) sanguinaria
4. In male (Figs 7O, 7P) valva short: length of its costal margin approximately equal to its greatest width; in female (Figs 9A–9C) posterior edge of lamella antevaginalis not straight: clearly round or with distinct medial projection (often pointed apically), ostium C-shaped....................................................................... L. (L.) purpuraria
– In male (Figs 7M, 7N) valva longer: length of its costal margin clearly exceeding its greatest width; in female (Figs 9D, 9E) posterior edge of lamella antevaginalis almost straight, without any projections, ostium not C-shaped.... L. (L.) plumularia
description: Published as part of Makhov, I. A., Gorbunov, P. Yu. & Lukhtanov, V. A., 2024, Lythria (Microlythria subgen. nov.) venustata Staudinger, 1882 (Lepidoptera: Geometridae): distribution and description of the female, with a brief review of the genus, pp. 29-48 in Zootaxa 5448 (1) on pages 38-40, DOI: 10.11646/zootaxa.5448.1.2, http://zenodo.org/record/11231079