Subleuconycta sola, Gyulai & Saldaitis, 2017

Gyulai, Péter & Saldaitis, Aidas, 2017, Three new taxa of Noctuidae from China (Lepidoptera: Noctuidae), Zootaxa 4311 (2), pp. 292-300 : 292-293

Subleuconycta sola , sp. nov. ( Figs. 1 , 13 )

Holotype: Male ( Fig. 1 ), China, W. Sichuan, road Yaan / Kangding , Erlang Shan Mt. , H – 2200 m, N29°87’340”, E102°30’ 970”, 2.vii.2011, Floriani & Saldaitis leg., slide No. PGY 2935m (coll. PGM, later will be deposited in the HNHM).

Diagnosis. Subleuconycta sola ( Fig. 1 ) is easily distinguishable from its three congeners both by external and genitalia features. By the single known specimen, it is the largest within the genera, wingspan 38 mm, versus those of Subleuconycta palshkovi ( Filipjev, 1937) ( Fig. 2 ) 31–33 mm, Subleuconycta sugii Boursin, 1962 with 33–37 mm, and Subleuconycta calonesiota Kiss, Wu & Matov, 2017 ( Fig. 3 ) with 33–35 mm. Externally, only S. palshkovi ( Fig 2 ) and S. calonesiota ( Fig 3 ) resemble the new species. Beside the somewhat larger size, S. sola can be easily distinguished from S. palshkovi by its much stronger, longer, black streak between the orbicular and reniform stigma in the forewings, and the evenly brownish suffused whitish hindwings, with much prominent discal spot. From S. calonesiota , the new species differs in the shorter, less expanded black streak between the orbicular and reniform stigma, not exceeding the reniform stigma below, and the less contrasting forewing pattern, with less discernible, mostly conjectural transversal crosslines in the forewings; the darker, evenly brownish suffused hindwings with more prominent discal spot and less conspicuous medial line. The separation is easier from both of S. palshkovi ( Fig. 14 ) and S. calonesiota ( Fig. 15 ) by the comparison of the male genitalia. Subleuconycta sola ( Fig. 13 ) has evenly broader valvae, broader corona and the most pointed saccular processus; in the vesica it has the largest, most prominent basal diverticulum, while the subterminal diverticulum lacks the cornuti field, being only slightly sclerotised–setosed; additionally, the new species has much longer uncus than in S.

calonesiota and somewhat longer than in S. palshkovi . Some of the external characters of S. sola sp. nov. (considerably finer, slenderer body; much stronger and expanded black streak between the orbicular and reniform macules and whitish ground coloured forewing, etc.), as well as some of the genitalia features (much longer uncus, basally with half width saccular extension) are so distinctive from the greyish brown coloured Taiwan S. sugii , the third described taxa of the genus, (figured in the revision of Kiss et al. 2017), that confusion is impossible. The correct identification is supported by the distributional pattern of the four congeners. Subleuconycta palshkovi have the widest range, known from the Russian Far East, Northeast China, Korean Peninsula and Japan ( Kiss et al. 2017), when S. calonesiota and S. sugii are endemic to Taiwan, whereas S. sola is known only from Sichuan.

Description ( Fig. 1 ). Wingspan 38 mm, length of forewing 17 mm. Antennae are filiform, basally white, distally brown; the frons whitish, collar brown, slightly whitish outlined; patagia whitish, brown outlined, being in connection with the three brown crossing lines of the whitish thorax. The vesture of the body and the ground colour of the forewings are grey and brown suffused whitish, however somewhat darker in the basal area. The most remarkable external features of the new species are the forewing with somewhat elongated but not pointed apex; the incompletely defined, but from the ground colour somewhat lighter orbicular and reniform stigmata with brown patch and a very conspicuous black streak between them, of which the inner end forms an asymmetric lying “V”, edging the orbicular spot, while the distal end is pointed below the reniform stigma; the more or less black outlined, double zigzagged basal line; the crenellate, mostly conjectural antemedial and postmedial crosslines; the interrupted subterminal line, formed by whitish small arrowhead–like spots and the blackish slight patches in the costa. The hindwing evenly brown suffused in which the cellular spot brown, well discernible, the medial (postdiscal) line diffuse. The underside of forewing brownish with the shade of the black streak between the spots, while the hindwing whitish with conspicuous brown shade of the cellular spot and the medial line.

The male genitalia ( Fig. 13 ) can be characterized by the rather long, evenly thin, straight, hooked uncus, apically with pointed tip; developed, elongated tegumen; broadly subdeltoidal juxta, laterally the broadest and pointed, dorsally with two slight appendages; V–shaped vinculum; the absence of the harpe; distally somewhat dorsally curved valvae, with almost parallel margins, conspicuous, long, apically pointed saccular process and broad corona; medially sicker, distally enlarged and more sclerotized aedeagus with two sclerotized distal bars inside and ample, membranous, somewhat dorsally everted vesica with a large prominent basal diverticulum and a subterminal diverticulum lacking the cornuti field, being only slightly sclerotised–setosed.

Biology and distribution. The new species is known from the Erlang Shan, at the eastern edge of the Tibetan plateau in China's Sichuan province. A single male was collected at ultraviolet light on beginning of July at altitude ranging 2200 m. The new species was collected in virgin mixed forest habitat dominated by various broad–leaved trees such as oaks ( Quercus dentata Thunberg , Quercus glauca Thunberg ), poplars ( Populus cathayana Rehder , Populus simonii Carrière ), elm ( Ulmus parvifolia Jacquin ), rhododendrons ( Rhododendron brachycarpum G. Don , Rhododendron dauricum Linnaeus ), and bamboos ( Phyllostachys ssp., Borinda ssp., Fargesia spp.).

Etymology. The new species is named “ sola ”, which means in Latin single, due to the fact that it was the single specimen in that well known locality at Erlang Shan mountains.

Figures

FIGURES 1 – 8. Subleuconycta & Isochlora spp. adults. 1. S. sola male, HT, China, W. Sichuan, PGY 2935 m (PGM / HNHM); 2. S. palshkovi, male, S. E. Russia, Vladivostok reg., PGY 4689 m (PGM); 3. S. calonesiota, male, HT, Taiwan, Tai – Tung prov., KA 1046 m (HNHM); 4. I. grumi multirosea ssp. n., male, HT, China, W. Sichuan, PGY 4467 m (PGM / HNHM); 5. I. grumi multirosea ssp. n., male, PT, China, W. Sichuan, PGY 4468 m (PGM); 6. I. grumi multirosea ssp. n., male, PT, China, W. Sichuan (AFM); 7. I. grumi grumi, male, Russia, Chita region, PGY 4490 m (PGM); 8. I. grumi grumi, female, China, Qinghai.

FIGURES 13 – 15. Subleuconycta spp. male genitalia. 13. S. sola. HT, W. Sichuan, PGY 2935 m (PGM / HNHM); 14. S. palshkovi, S. E. Rusia, Vladivostok reg., PGY 4689 m (PGM); 15. S. calonesiota, HT, Taiwan, Tai – Tung prov., KA 1046 m (HNHM).