Some dragonfly karyotypes from the Voltaic Republic (Haute Volta), West Africa

From Bobo-Dioulasso and the broader surroundings the male germ cell complements were examined of the following 9 spp.: Coenagrionidae: Pseudagrion whellani Pinhey; Libellulidae: Orthetrum b. brachia!e( P, de Beauv.). O. chrysostigma IBurnt.). O. guineense Ris. O. monardi Schmidt, Palpopleura lucia portia (Dru,). Trithemis atra Pinhey, T. imitata Pinhey and T. kirbyi ardens Gerst. All of them possess 13 elements in the haploid set; an m-bivalent is present in all libellulids. The P. ii /tc/Zan/complement apparently originates from an n = 14 set, but it is not clear whether or not the original X participates in the fusion, hence the identity of the small element and the mode of sex determination are uncertain. O. brachiale is the only sp. earlier studied cytologically. While the karyotype of a Kenyan specimen is clearly of a secondary origin (n 6 = 11, no m. increased chiasma frequency; cf. KIAUTA. 1969. Arnoldia. Rhodesia 4 [15]: 1-8). those of the 2 spec, from Upper Volta are of the usual Orthetrum type.