Erannis caspica, M, 2003

M, Gy., 2003, New Species Of The Genus Erannis Hübner, [1825] 1816 From The North-West Himalaya And Iran (Lepidoptera, Geometridae), Acta Zoologica Academiae Scientiarum Hungaricae 49 (2), pp. 153-158 : 156-158

Erannis caspica sp. n.

( Figs 5–8 , 10 )

Holotype: male, “ Iran, Prov. Gilan, 15 km SW of Rast, Disku , 200 m, 17–18.XI.2000, leg. B. Benedek & Gy. Fábián ” (coll. HNHM).

Paratypes: 12 males, with the same data as the holotype ; 10 males, Azerbaijan, Talysh , Massali, Isty-su, 22–25.X.1987, leg. Kazarjan (coll. GY. M. LÁSZLÓ, Budapest; GY. FÁBIÁN, Budapest; HNHM Budapest; ZMKU Kiev) .

Slide No. LG 1744.

Diagnosis: The new species is closely related to Erannis defoliaria (CLERCK, 1759) , but easily distinguishable by its generally smaller size: the wingspan and the length of forewing of E. defoliaria vary between 36–50 and 20–26 mm, respectively, while those of E. caspica are 31–38 and 16–20 mm. The forewing of the new species is considerably narrower and more elongated than that of E. defoliaria . The brownish irroration on the wings of E. caspica is much weaker than in E. defoliaria , in some specimens even completely absent. The discal spot on the forewing of the new species is situated considerably closer to the postmedial line than in E. defoliaria . Most specimens of the new species have variably strongly marked, almost straight transverse line on the hindwing, while the crossline of the hindwing of E. defoliaria is regularly absent. There are remarkable differences between the two species in the configuration of certain parts of the male genitalia, too. The triangular costal lobe of valva of E. caspica has slightly concave distal margin, covered with somewhat thinner spines, while that of E. defoliaria has straight distal margin, covered with stronger, thicker spines. Moreover, the medio-distal plate of juxta of E. caspica is considerably narrower, more elongated than that of E. defoliaria .

Description: Wingspan 31–38 mm, length of forewing 16–20 mm. Male. Head and collar dark brown, antenna bipectinate, red-brown. Thorax narrow, red-brown, tegulae covered with long, yellowish and red-brown hair-scales. Abdomen dorsally red-brown, laterally and ventrally yellowish brown. Forewing relatively narrow, elongated, apically rounded, outer margin more or less straight. Ground colour variable, pale yellow or pale ochreous-brown, with usually fine, scarce brownish irroration; median area and inner part of marginal field usually covered with darkbrown or or - ange-brown scales. Basal line poorly visible, marked only if even at ventral margin; subbasal line evenly, antemedial line sinuously arcuate, indistinct, diffuse. Medial line indistinct, poorly visible, represented by a row of brownish scales. Discal spot rounded, more or less strongly marked by dark brown scales. Postmedial line usually well defined, relatively narrow, distinct, its ventral half slightly sinuous, almost straight, costal half starting with an obtuse angle towards terminal area, its costal third strongly sinuous. Praeterminal line indistinct, shade-like, rather sinuous, sometimes poorly visible. Subterminal line interrupted, sinuous, usually consisting of elongated darkbrown patches, some - times may be absent. Terminal line very narrow, continuous, pale brown, cilia relatively long, yellowish grey, usually chequered with greyish-brown. Hindwing yellowish white, sometimes with rather sparse brownish irroration, veins marked with yellowish scales; transverse line indistinct or absent, interrupted, slightly arcuate. Discal spot strongly marked; terminal line as on forewing; cilia pale yellow. Underside of wings pale ochreous-grey, discal spots and transverse lines visible.

Male genitalia ( Fig. 10 ). Uncus triangular, broad at base, apically truncate. Gnathos ribbonlike, with a relatively large, apically rounded, triangular plate medially. Tegumen triangular, robust. Juxta large, well sclerotized, shield-like, with a rather elongated, relatively narrow, rounded dorsal lobe. Vinculum relatively short, saccus broadly rounded. Valva rather short, broad, ventral margin strongly sinuous, costal margin angled, apically rounded. Basal half of costal margin strongly sclerotized, with large, distally concave, apically rounded lobe projecting towards valval apex, covered distally with medium strong, relatively short spines. Medio-basal part of valva with small, strongly sclerotized, tapering, apically pointed extension. Transtilla quadrangular, weakly sclerotized, relatively short and broad. Aedeagus short, broad, apically with tongue-shaped plate; vesica short, with a cornuti field consisting of rather long cornuti, appearing as a single large cornutus.

Female unknown.

Bionomics and distribution. The new species occurs in the north-western chains of the Elburz mountains. The species inhabits the rather wet forests of the northern slopes at relatively low altitudes (200–1000 m). The specimens were collected at light between the end of October and the middle of November. The female and the preimaginal stages are unknown, the larval foodplants are most probably various deciduous trees and bushes.

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Acknowledgements – The author is greatly indebted to Dr AXEL HAUSMANN (Munich) and Dr DIETER STUENING (Bonn) for the possibility to work in their museum collections, checking the type material, and for the loan of specimens for the studies. I am also grateful to Mr MANFRED SOMMERER (Munich), Dr IGOR KOSTJUK (Kiev), Mr GYÖRGY FÁBIÁN and Mr GÁBOR RONKAY (Budapest) for the opportunity to study their Erannis material. Special thanks are due to Dr LÁSZLÓ RONKAY for the kind help and advice in the preparation of the material and manuscript.

Figures

Figs 1–8. Erannis males. E. kashmirensis: 1 =holotype; 2–4 =paratypes: 2 =Pakistan, Kashmir, Deosai Mts, 3 =Pakistan, Kashmir, Deosai Mts, 4 =Pakistan, Indus valley, Barseen. 5–8 = E. caspica: 5 =holotype; paratypes: 6 =Iran, Prov.Gilan, Disku, 7 =Iran, Prov. Gilan, Disku, 8 =Azer -

Figs 9–10. Erannis male genitalia capsule. 9 = E. kashmirensis, holotype; 10 = E. caspica, paratype (Iran, Prov. Gilan, slide No. LG 1744). (Aedeagus with larger magnification)