Karyotypes and testis structure of 14 species representing 9 genera (Latissus, Bubastia, Falcidius, Kervillea, Mulsantereum, Mycterodus, Scorlupaster, Scorlupella and Zopherisca) of the planthopper tribe Issini (Issidae) are presented. All the karyotypes are illustrated by meiotic and occasionally mitotic figures. The male karyotypes of most of the species analyzed are 2n = 26 + X, the exception being Falcidius limbatus, which has a karyotype of 2n = 24 + neo-XY. The latter is the first report of the neo-XY system in the family Issidae. The species studied are found to be similar in having NORs on the largest pair of autosomes, but differ significantly in the amount and distribution of C-heterochromatin along the chromosomes. In contrast to the conserved chromosome numbers, the highly variable follicle number in the testes suggests rapid evolution of the tribe Issini. On the basis of its specific follicle number, it is proposed that Zopherisca tendinosa skaloula Gnezdilov & Drosopoulos, 2006 be upgrade to a species: Z. skaloula stat. n. The cytological and taxonomic significance of results presented are discussed.
The aim of this study was to obtain information on the karyotypes, testes and ovaries of three fulgoroid families, mainly in the Issidae but also in the Caliscelidae and Acanaloniidae. For the Issidae, the data is for 19 species belonging to 11 genera of the subtribes Issina (2 species, 1 genus), Hysteropterina (14 species, 9 genera) and Agalmatiina (3 species, 2 genera) of the tribe Issini. The male karyotypes are shown to be quite uniform across the tribe, with 2n = 26 + X in all species studied except Latilica maculipes (Melichar, 1906) with 2n = 24 + X. The modal karyotype, 2n = 26 + X, matches the most probable ancestral state in the Fulgoroidea. In the majority of cases the number of seminal follicles in males and ovarioles in females are stable within but fairly variable among the species, the modal value of the follicle number is 10 per testis. Contrary to what might be expected from other fulgoroid families, such as the Dictyopharidae and Delphacidae, the variability in these characters revealed neither regular trends nor evident correspondence with the taxonomy of Issidae. In the Caliscelidae, all species studied had testes consisting of 6 follicles each and karyotypes of 2n = 24 + X and 26 + XY, respectively, in 3 and 1 species. The only representative studied of the Acanaloniidae, Acanalonia bivittata (Say, 1825), had 2n = 24 + X and 13 follicles in its testis. The variability in all the characters investigated is discussed and compared to other fulgoroid families, primarily to the most extensively studied families, Delphacidae and Dictyopharidae.