Tortrilema Volynkin, 2021

Volynkin, Anton V., 2024, Revised status of the genus Tortrilema Volynkin with descriptions of a new genus and a new species (Lepidoptera: Erebidae: Arctiinae: Lithosiini), Ecologica Montenegrina 77, pp. 169-179 : 170-171

Genus Tortrilema Volynkin, 2021 , stat. rev.

Manulea Wallengren, 1863 subgenus Tortrilema Volynkin, 2021 , Ecologica Montenegrina , 48: 10. Type species: Lithosia postmaculosa Matsumura, 1927 , by original designation.

Note. The genus is herein restricted to the ‘ Manulea (Tortrilema) postmaculosa species-group’ sensu Volynkin (2021).

Diagnosis. Species of the genus ( Figs 1–12 ) are morphologically similar to Parabitecta (type species: Parabitecta flava Draeseke, 1926 ) ( Figs 17–20 ) but the imagoes can be distinguished by the lack of the subbasal androconial patch on the male forewing upperside, and the more substantial sexual dimorphism with female having reduced forewing pattern. Compared to Parabitecta ( Fig. 26 ), the male genitalia of Tortrilema ( Figs 21–23 ) are characterised by the combination of the following features. (1) The vinculum is solid whereas in Parabitecta the vincular arms are ventrally connected by the membranous commissure. (2) The intravincular membrane lacks the corema and caselli, which are present in Parabitecta . (3) The tendons are thin, ribbon-like and fused with each other whereas in Parabitecta , they are short, plate-like and separated from each other by the diaphragmal membrane. (4) The valva lacks the lamella centralis and apical sclerotised protrusion, which are present in Parabitecta . (5) The distal saccular process bears a short, denticle-like basal protrusion whereas the saccular process of Parabitecta is smooth. (6) The phallus is markedly narrower than in Parabitecta and has a shorter coecum. (7) The vesica is considerably broader and longer than in Parabitecta and bears clusters of scobination. The female genitalia of Tortrilema ( Figs 27–29 ) differ from Parabitecta ( Fig. 31 ) in the following features. (1) The antevaginal plate is absent whereas it is well-developed and pocket-like in Parabitecta . (2) The ductus bursae is dorso-ventrally flattened and bears large dorsal and ventral sclerotised plates whereas it is membranous and tubular in Parabitecta . (3) The anterior section of the corpus bursae bears a small elliptical signum or lacks it whereas Parabitecta has two long ribbon-like longitudinal signa. (4) The appendix bursae is very short and conical whereas it is markedly larger and elongate sack-like in Parabitecta . The detailed comparison with another similar genus, Tortribitecta gen. n. is provided below in the diagnosis of the latter species.

Distribution. Species of the genus are known from southwestern and southern mainland China,

Taiwan Island and northern Mainland Southeast Asia (northern Vietnam).

Figures

Figures 1–12. Adults of Tortrilema ssp. Depositories of the specimens: 1–8, 11 and 12 in MWM/ZSM; 9 and 10 in AFM.

Figures 13–20. Adults of Tortribitecta gen. n. (13–16) and Parabitecta (17–20) ssp. Depositories of the specimens: 13, 14, and 17–20 in MWM/ZSM; 15 and 16 in AFM.

Figures 24–26. Male genitalia of Tortribitecta gen. n. (24, 25) and Parabitecta (26) ssp. Depositories of the specimens dissected: 24 and 26 in MWM/ZSM; 25 in AFM.

Figures 21–23. Male genitalia of Tortrilema ssp. The specimens dissected are deposited in MWM/ZSM.

Figures 27–31. Female genitalia of Tortrilema (27–29), Tortribitecta gen. n. (30) and Parabitecta (31) ssp. Depositories of the specimens dissected: 27 and 29–31 in MWM/ZSM; 28 in AFM.