Diarsia huilini, Gyulai & Saldaitis, 2020

Gyulai, Peter & Saldaitis, Aidas, 2020, Notes on the genus Diarsia with description of a new species from China (Lepidoptera: Noctuidae), Zootaxa 4810 (2), pp. 395-400 : 395-399

2. Diarsia huilini sp. n. ( Figs 3–5 , 9, 10 )

Holotype. Male ( Figs 3, 5 , 9 ), China, W. Sichuan, road Yaan / Kangding , Erlang Shan Mt. , H- 2000 m, N 29°87.340”, E102°30.970 ”, 27.VI.2019, Butvila & Saldaitis leg, slide no. GYP 5104m (coll. PGM, later to be deposited in the HNHM).

Paratypes. 2 males ( Figs 4 , 10 ), with the same data as the holotype, slide GYP 5208m (colls AFM & ASV) .

Diagnosis. The new species is remarkably dissimilar from all the close relative species by the dark bluish thoracic scales, the black legs with fine yellow rings on the segments and the unicolorous sallow—ochre and fawn, with slight bluish (particularly in the basal area) and pale reddish suffusion (in the marginal area) of forewings. Thus, the separation from the relative species is very easy for the first sight. The male genitalia structure of the new species ( Figs 9–10 ) reveals the closest affinity to the Diarsia pallens Chen, 1993 ( Figs 6–8 & 11–12 ) (occurs also only in Sichuan and collected sympatric with the new species), from which the new species well differs externally by its dark bluish thoracic scales, unicolorous sallow—ochre and fawn ground colour of forewings, obscure wing pattern, much darker, brown ground colour of hindwings and the reddish cilia of the wings. In the male genitalia, D. huilini can be distinguished from D. pallens by its tighter uncus; smaller, less dorsally curved cucullus; conspicuously smaller, shorter ampulla; very different juxta, in which the deep dorsal medial incision is u-shaped, the diverging dorsal extensions are curved, the ventral–medial part more extended and triangular, while those are v-shaped, the diverging dorsal extensions straight, the ventral–medial part less extended in the D. pallens ; the ventral medial costa of the valvae in the new species is less extended and rounded. The differences between the two species are very significant in the vesica structure: in the new species, the basal, cuff-shaped part of the vesica is densely covered by strongly sclerotized acute bristles, forming a plate-shaped belt extending to the globular medial section of vesica, is much larger and longer; the bunches of spines are very extended in the basal-subbasal-medial sections of the vesica and conspicuously stronger, longer than in D. pallens , in which the spines are very fine, much shorter, however more dense, covering almost the whole inner surface of the globular part of the vesica; additionally the aedeagus tighter, longer.

Note. The holotype male primary type of D. pallens ( Fig. 6 ) is undissected. However, the genitalia drawing of a dissected male ( Fig. 12 ) presented in the original description by Chen (1993) reveals the identity with the dissected D. pallens ( Fig. 11 ) particularly by the very large, long ampulla. Obviously, the holotype of D. pallens ( Fig. 6 ) and the specimens figured here ( Figs 7, 8 ) belong to the same species.

Description. ( Figs 3–5 ) Forewing length 14–15 mm. Antennae are thin, brown, red-brown, filiform; palpi black, last segment yellowish. Head and thoracic vesture are dark bluish, reddish on the abdomen, while on the under side there are large black tufts around the eyes, the body is covered by dense red vesture; legs are black with fine yellow rings on the segments. Ground colour of forewing is unicolorous sallow—ochre and fawn, with slight bluish suffusion, particularly in the basal area and pale reddish suffusion in the marginal area. The wing pattern is fine, macules are slightly defined, due to the absence of the outlines and the ground colour of them is the same as of forewings; claviform spot is present as a black dot only. Transverse lines fine, double, brown, medial fascia pale brown, diffuse. The antemedial lines are slightly zigzag, the postmedial lines arched and crenated, subterminal lines conjectural. The starting points in the costa of the transverse lines and the subapical dash are fine, black. Hindwings are brown, discal spots darker brown, the cilia is pinkish. Under side ( Fig. 5 ) of wings is dark brown with strong red suffusion. Male genitalia. The main features of the new species ( Figs 9, 10 ) are as follows: rather long, almost evenly slender, terminally acute uncus with a large tuft of long hairs; slightly curved, terminally finely rounded harpe; large, strong, finger-like, slightly curved, terminally rounded ampulla; shieldlike juxta, which dorsally is divided by a medial u-shaped incision to two diverging, slightly curved appendages, while the ventral part broadly triangular with bilateral small symmetrical extensions; ventro–medially broaden, rounded valva with somewhat detached large, hairy, distally elongated, terminally tapering cucullus and corona, with numerous large setae; curved aedeagus, with large, strongly sclerotized dentate belt –like plate running from the aedeagus carina and extending onto the subbasal section of the vesica, while the basal-subbasal-medial sections of the vesica are densely covered with very extended bunches of strong, long spines.

Female is unknown.

Biology and distribution. The new species is known only from the Erlang Shan Mountains at the eastern edge of the Tibetan plateau in China’s Sichuan province. Three males were collected at ultraviolet light in end of June at altitude ranging 2000 m. The new species was collected in a 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 in honour of Mr. Han Hui-Lin, specialist of Asiatic Noctuidae .

Figures

FIGURES 1–8. Diarsia spp. adults. 1. D. zillii, holotype, male, China, Sichuan (PGM/HNHM); 2. D. zillii, female, China, Sichuan (AFM); 3. D. huilini sp. n., holotype, China, Sichuan (PGM/HNHM); 4. D. huilini sp. n., paratype, China, Sichuan (ASV); 5. D. huilini sp. n., holotype, China, Sichuan, underside (PGM/HNHM); 6. D. pallens type, China, Sichuan (IZC; photo by Han Hui-Lin); 7. D. pallens, China, Sichuan, (PGM). 8. D. pallens, China, Sichuan (ASV).

FIGURES 9–11. Diarsia spp. male genitalia. 9. D. huilini sp. n., holotype, male, China, Sichuan, GYP5104m (PGM/HNHM); 10. D. huilini sp. n., paratype, male, China, Sichuan, GYP5208m (ASV); 11. D. pallens, male, China, Sichuan, GYP 2849m (PGM).

FIGURES 12–13. Diarsia spp. male and female genitalia. 12. Original drawing from description of D. pallens by Chen, 1993; 13. D. zillii, female, China, Sichuan, GYP5029f (AFM).