Diarsia alexanderi, 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 : 134-137

publication ID	https://doi.org/ 10.37828/em.2019.22.10
publication LSID	urn:lsid:zoobank.org:pub:DCE06D38-9F41-4F84-8200-D9EC92966367
persistent identifier	https://treatment.plazi.org/id/F9F964F8-3027-4487-973C-DB7A543C848D
taxon LSID	lsid:zoobank.org:act:F9F964F8-3027-4487-973C-DB7A543C848D
treatment provided by	Felipe
scientific name	Diarsia alexanderi
status	sp. nov.

Treatment

Diarsia alexanderi sp. n.

( Figs 10, 11, 12 View Figures 9–16 , 50 View Figures 50-54 , 74 View Figures 72-77 )

Type material. Holotype: male ( Fig. 10 View Figures 9–16 ), China, W Sichuan, road Yaan / Kangding, Erlang Shan Mt. , H – 2161 m, N29°87’340”, E102°30’970”, 11–12.IX.2017, Saldaitis leg, slide GYP 4882, (coll. PGM, later to be deposited in the HNHM).

Paratypes: 1 male, 5 females, with the same data as holotype ; 1 male, 1 female, China, W Sichuan, 25km. N. from Batang, H – 3100 m, dry valley, N30°12.049’, E099°14.078’, 19–20.IX.2017, Saldaitis leg, (colls AFM & ASV), slide GYP 4925 (female) GoogleMaps .

Diagnosis. The new species ( Figs 10, 11, 12 View Figures 9–16 ) belongs to the hoenei species group, although externally the most resembling species is the Diarsia coenostola Boursin, 1954 ( Figs 5, 6 View Figures 1–8 ), from which it can be separated by the less elongate forewing apex, crenated antemedial line (which is tortuous in D. coenostola ), arcuate postmedial line and obsolescence subterminal line, which is a considerable yellow line in the D. coenostola . It is more distinctive from the D. robusta Boursin, 1954 ( Figs 13, 14 View Figures 9–16 ); beside by the above mentioned features, in the new species the reniform stigmata are brownish, whereas those are yellowish coloured in the D. robusta . The brown ground colour of the forewing with light ochre–brown basal and medial area and much darker brown subterminal–terminal fields provide an easy separation also from the further species of the D. hoenei species group, which are resembling in most features of the genitalia (the most similar genitalia structure have the Diarsia excelsa Hreblay & Ronkay, 1998 ) ( Figs 15, 16 View Figures 9–16 ), however have reddish, red– brown, or rarely dark ochre and less variagate forewings. In the male genitalia, the most remarkable differences in comparison D. alexanderi ( Fig. 50 View Figures 50-54 ) to D. coenostola ( Fig. 52 View Figures 50-54 ) are included: the new species have longer uncus and very differently shaped, shield – like juxta, in which the slight dorsal incision separates two dorsal, symmetric small extensions with uneven dorsal surface, bearing both of them one–one tiny peaks in the middle; while this is V–shaped with a broad but shallow depression in the D. coenostola . This juxta shape is unique and the best key for separation from the rest of the taxa of the hoenei species group and also from those of the D. robusta ( Fig. 53 View Figures 50-54 ), which have broadly triangular juxta and the two tiny dorsal thorns are in the middle, close one to another. In the hoenei species group, the most corresponding species by the genitalia structure to D. alexanderi is the D. excelsa ( Fig. 54 View Figures 50-54 ), (which have red–brown forewings), however in the new species the ampulla is much recurved, tha harpe somewhat longer, the valva more extended medio–ventrally and the dorsal surface of juxta broader, more uneven, slightly pointed in the middle of both symmetrical extensions; while the dorsal section of juxta bears two flap–like symmetrical extensions in the D. excelsa . In the female genitalia, the most conspicuous differences are, in comparison D. alexanderi ( Fig. 74 View Figures 72-77 ), to D. excelsa ( Fig. 75 View Figures 72-77 ), are the shorter, however much broader, less sclerotized ductus bursae, significantly larger, globular appendix bursae and the remarkably larger corpus bursae. No reliable female genitalia of the externally and in the male genitalia more different and remote D. robusta and D. coenostola were available.

Description. A large species ( Figs10, 11, 12 View Figures 9–16 ), wingspan 36–39 mm; females are slightly larger than the males. Antennae are thin, filiform in both sexes. The vesture of the head and thorax is brown. The forewings are varied brown coloured with light ochre–brown basal and medial area and much darker, brown subterminal–terminal area; while these are more unicolorous in the females. The orbicular and reniform stigmata are the same as the ground colour, being incompletely encircled with black definition. The wing pattern is dark brown, the ante– and postmedial transverse lines are double, the former one crenated, the latter one arched, the subterminal line obsolescent; the medial fascia broad, arched, diffuse. Hindwings are brown, discal spot defined by a darker brown, fine arch. Male genitalia. The most typical features ( Fig. 50 View Figures 50-54 ) are the rather long, pointed uncus; strong, somewhat curved harpe; laterally erected, long, medially dorsally recurved ampulla; shield –like juxta, in which the slight dorsal incision separates two dorsal, symmetric flap– like small extensions, bearing both of them one–one tiny peak in the middle; medially broaden valva with somewhat detached large cucullus with broad “neck” and long corona covered with numerous long setae; curved, short aedeagus and ample, globular vesica with a strongly sclerotized, long serrate bar of the carina extending toward the basal, slightly sclerotized part of the spacious vesica, in which a large field of scobinate ventral surface structure visible. Female genitalia. The main characters ( Fig. 74 View Figures 72-77 ) are the broad, setose papillae anales and the short apophyses anteriores; strongly sclerotized, U–shaped, broad, postero–medially deeply depressed antrum with two sclerotized, lateral, lobate, posteriorly tapering extensions; broad, more or less sclerotized, longitudinally ribbed ductus bursae; large, ample, globular appendix bursae and long, spacious, saccate corpus bursae, with one long and two shorter signa in its wall.

Biology and distribution. The new species is known from two valleys at the eastern edge of the Tibetan plateau in Chinese Sichuan province. The holotype male and few females were collected at ultraviolet light at altitude ranging 2200 m, in middle of September. Diarsia alexanderi 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. ).