The chromosomes of some dragonflies from the Langtang Valley, Central Nepal

The male germ cell complements are described of Drepanosticta sp. (Platystictidae), Indolestes cyanea (Sel.) (Lestidae), Anisopleura comes Sel. (Euphaeidaé). Neallogaster sp. aff. hermionae (Fraser) ( Cordulegasteridae), and Orthetrum japonicum internum McLachl. (Libellulidae). In all of these the chromosome number is n <5 = 13, while a pair of m-elements is lacking in Drepanosticta sp. and in Neallogaster. Save for O. j. internum none of the species has been previously studied cytologically. I. cyanea is characterized by an extremely large autosome pair (bivalent). The karyotype of A. comes is similar to that of Bayadera indica (Sel.), but differs considerably from the complement of the more ’’primitive” member of the family, Epallage fatime (Charp.). Neallogaster sp. is the first cordulegasteride species lacking definitely the m-chromosomes. The latter and Drepanosticta sp. are new to the Nepalese fauna.