Bekchanov Muzaffarbek Xudaybergenovich Announcement of the defense of the doctoral (PhD) dissertation I. General Information. Theme of the dissertation, specialty code (the name of the discipline to which the degree is awarded): "Bioecology of butterflies of the Khorezm oasis (Lepidoptera: Pieridae) and problems of their conservation", 03.00.06 - Zoology (biological sciences). Dissertation subject registration number: B2018.1.PhD/B158 Supervisor: Abdullaev Ikram Iskandarovich, Doctor of Biological Sciences, Professor. Name of the institution where the dissertation was completed: Urgench State University Name of the institution (institutions) where the IC operates, IC number: Institute of Zoology, National University of Uzbekistan, DSc.29.08.2017.V.52.01. Official opponents: Medetov Maxsetbay Japakovich, Doctor of Biological Sciences; Khusanov Alisher Karimovich, Doctor of Biological Sciences (PhD), Associate Professor. Leading organization: Karakalpak State University.