Diarsia reserva, Gyulai & Saldaitis, 2019

Gyulai, Peter & Saldaitis, Aidas, 2019, Notes on the genus Diarsia with the description of seven new species from China (Lepidoptera: Noctuidae), Ecologica Montenegrina 22, pp. 128-151 : 137-145

Diarsia reserva sp. n.

( Figs 17–20 , 55, 56 , 76 ).

Type material. Holotype: male ( Fig. 17 ), China, prov. Yunnan, Bailakou pass, 3500 m, 63 km of Zhongdian, 1–3.VIII. 2010, leg. S Murzin, slide GYP 5022, (coll. PGM, later to be deposited in the HNHM).

Paratypes: 4 males, 1 female with the same data as holotype, (coll PGM) ; 3 males, China, prov. S. Sichuan, 20 km S of Xichang , 3000 m, 20–23.VII.2005, leg. S. Murzin (coll PGM), slides: GYP 2604 (male), GYP 5025 (male), GYP 5026 (male), GYP 5029 (female) .

Diagnosis. The most recent investigations on the chalcea species group revealed the existence of another species in Yunnan and Sichuan, which is described here as new to science. Very likely, further one or two species are hidden in this species group, being close relatives to the D. mandarinella (Hampson, 1903) (= Graphiphora mandarina Leech, 1900 ; = Agrotis mandarinella (Hampson, 1903) (replacement name) ( Figs 21, 22 ), D. dichroa Boursin, 1954 ( Figs 23, 24 ), D. metadichroa Varga & Ronkay, 2007 , D. scotodichroa Varga & Ronkay, 2007 and D. hanmienses Xiong & Han, 2010 . The holotypes of the latter four species are figured in colour by Varga & Ronkay (2007) and Xiong & Han (2010). The male syntype of D. mandarinella is figured here ( Fig 21 ), its genitalia by Boursin as the type (1948c, plate 11, fig. 47); however this figure is poor and the vesica is not everted exactly; furthermore it was impossible to find in London, since had been deposited in a vial by Tams, without correct marking (personal comm. by A. Zilli). Later, Boursin found a further male in ZFMK, Bonn, which was published by him in 1954, with a footnote, mentioning, that it proved to be also D. mandarinella . However, its genitalia was not dissected, the specimen is somewhat worn and faded, and externally somewhat differs from the male syntype; thus conspecifity is debatable. Additionally, the above mentioned species are very similar to one another, in both the external features and genitalia structures, thus authors describe here only D. reserve , which well differs in the genitalia from all but one in this species group. The ground colour and wing pattern of the new species are apparently almost the same as in the closest relatives, but the orbicular and reniform stigmata are conspicuously encircled with yellow or rarely pale reddish–brown; additionally, the terminal section of the palpi is conspicuously clear white, while these are whitish, pale ochre, or light brown in the close relatives. Furthermore, it well differs from the male syntype of D. mandarinella , by the variegated, reddish–brown ground colour of forewings, while these are more unicolorous in the D. mandarinella . In the male genitalia, the structure is apparently very similar in the species group; the key features for separation are in the shape and size of ampulla, juxta, aedeagus and vesica armature. D. reserva ( Figs 55, 56 ) compared to the closest relative species ( Figs 57, 58 ) has more or less broader and deeper dorsal incision in the juxta; huge, strongly curved ampulla, which resembles only to those of the D. mandarinella (see: Boursin, 1948 c, plate 11, fig. 47 and Fig. 57 in this article), in the species group. The most conspicuous differences are in the shape and structure of aedeagus and vesica. Only the new species has straight or almost straight aedeagus with the absence of the acute, strong, thorn–like ventral process; additionally, the aedeagus bears an unique, longitudinal strongly sclerotized configuration, starting broadly then converging, finally running parallel, then meeting in a slight or obtuse node (which is best visible in the lateral view, however is not an acute, strong, thorn–like process, as in the close related species), continuing with a sclerotized thin bar onto the basal part of vesica and ending in a strongly sclerotized, subbasal dentate plate. The vesica is less elongate than in the similar species, more broadly covered by the large number of tiny spiculi and lacks the other structures and the small subterminal diverticulum, which are typical in most of the relative species. In the female genitalia, D. reserva ( Fig. 76 ) can be easily distinguished by the structure of the ductus bursae. The new species has the broadest anterior section of the ductus bursae, which is strongly sclerotized and not rugulosus, as in all of the close relatives ( Fig. 77 and Varga & Ronkay (2007); the female genitalia of the D. mandarinella was not available).

Description. ( Figs 17–20 ). Wingspan 30–33 mm. Antennae are thin, filiform, palpi dark brown, distally white; vertex pale ochre. Ground colour of the head and thorax vesture and of the forewings is variegated; red–brown, however somewhat darker suffused in the inner edge. The wing pattern is well recognizable, defined with blackish or dark brown. The basal– and antemedial lines are slightly zigzag, the postmedial lines arched and crenated, subterminal lines wavy, pale ochre or reddish brown. The orbicular and reniform stigmata are typical, completely outlined with yellow or pale reddish–brown; the claviform stigmata conjectural. Hindwings are brown, discal spot is a darker brown arch. Male genitalia. The main features of D. reserva ( Figs 55, 56 ) are the followings: rather long, almost evenly thin, terminally tapering uncus; falcate, terminally tapering harpe; huge, curved ampulla; shield–like juxta with dorsal appendage, which is divided to two symmetrical, diverging extensions by a deep medial incision; ventro–medially broaden valva with somewhat detached large, hairy cucullus and corona, with numerous thin setae; straight aedeagus, having a longitudinal strongly sclerotized configuration, starting broadly then converging and running parallel then meeting in a slight or obtuse node, continuing with a sclerotized slim bar onto the basal part of vesica and ending in a large, strongly sclerotized, subbasal dentate plate; cylindrical vesica, which is broadly and densely covered by a large number of tiny spiculi. Female genitalia. The main characters ( Fig. 76 ) are the setose, elongate papillae anales, short apophyses anteriores and long apophyses posteriores; strongly sclerotized, antrum with large, bilateral symmetrical lobi and a flap–like antero–medial appendage; large, long, medially slightly constructed ductus bursae; small, not detached appendix bursae and spacious, saccate corpus bursae with two longitudinal and a small signa.

Biology and distribution. The new species is known from the Chinese provinces of Yunnan and Sichuan only; a mid–summer species.

Etymology. The Latin “reserva ” means “reserve ”, “spare”, indicates that this new species was found among the debatable specimens of the chalcea group.

Figures

Figures 17–24. Diarsia spp. adults. 17. D. reserva sp. n., holotype, male, China, Yunnan (PGM); 18. D. reserva sp. n., paratype, male, China, Yunnan (PGM); 19. D. reserva sp. n., paratype, male, China, S. Sichuan (PGM); 20. D. reserva sp. n., paratype, female, China, Yunnan (PGM); 21. D. mandarinella, syntype, male, China, Sichuan (NHMUK); 22. D. mandarinella, male, China, W Sichuan (PGM); 23. D. dichroa, male, China, Yunnan (PGM); 24. D. dichroa, female, China, Sichuan (PGM).

Figures 54-58. Diarsia spp. male genitalia. 55. D. reserva sp. n., holotype, China, Yunnan, GYP 5022 (PGM); 56. D. reserva sp. n., paratype, China, Yunnan, GYP 2604 (PGM); 57. D. mandarinella, China, W Sichuan, GYP 4164 (PGM); 58. D. dichroa, China, Yunnan, RL 8935 (PGM).

Figures 72-77. Diarsia spp. female genitalia. 72. D. rubrifusa sp. n., paratype, China, Fujian, GYP 2959 (PGM); 73. D. unica, Taiwan, Nantou, slide GYP 5012 (PGM); 74. D. alexanderi sp. n., paratype, China, W Sichuan, slide GYP 4925 (ASV); 75. D. excelsa, Nepal, Kanchenjunga, GYP 5031 (PGM); 76. D. reserva sp. n., paratype, China, Sichuan, GYP 5029 (PGM); 77. D. dichroa, China, Sichuan, GYP 3266 (PGM).