S. Mahunka szerk.: Folia Entomologica Hungarica 61. (Budapest, 2000)

Plebejus fyodor sp. n. from the Tibetan Plateau (Lepidoptera: Lycaenidae) Zs. Bálint, Y. F. Hsu and K. Johnson Plebejus fyodor sp. n. from the Tibetan Plateau (Lepidoptera: Lycaenidae) — A new species of "blue butterfly" (Lycaenidae, Polyommatini), Plebejus fyodor, is described from Sichuan Province, China, and distinguished from other members of the íífas-species group. With 7 original figures. Key words: taxonomy, Lepidoptera, idas-species group, Tibet. INTRODUCTION During field work on the high mountain plateau of Tibet, the junior author discovered a distinct species of "blue butterfly" in Sichuan Province, China. This new species is described below in the context of its closest relatives, members of the /oas-species group (= subgenus Lycaeides Hübner, [1819] of Plebejus Kluk, 1802. Plebejus fyodor Hsu, Bálint et Johnson sp. n. (Figs 1-6) Holotype — male, China, Sichuan Prov., Aba Zhou, Hongyuan Xian, Qiongxi, 3500 m, VI.7.1992, leg. Y. F. Hsu, deposited in Zoological Institute of Academia Sinica, Beijing, China. Paratypes — three males, two females deposited in Hungarian Natural History Museum (HNHM), with data of Holotype (gen. prep. Bálint glycerin vial nos 848, 849 (males), 850, 851 (females), Bálint, HNHM, respectively). 7 male and 3 female paratypes: Department of Biology, National Taiwan Normal University (Taipei, Taiwan); holotype male and paratype female, plus 4 male paratypes: Zoological Institute of Academica Sinica (Beijing, China); 3 male and 1 female paratypes: the Natural History Museum (London, UK); 3 male and 1 female paratypes: American Museum of Natural History (New York, USA); 3 male paratypes: Chongqing Natural History Museum (Chongqing, China). Diagnosis — P. fyodor averages smaller in size than all the other look-alike P. idas or P. argyrognomon subspecies. The only similar taxa in size are P. subsolanus boreas and P. christophi christophi but the wing dorsum of P. subsolanus boreas is brown on both sexes (see Key) and the underside ground colour of P. christophi is much lighter (whitish