Meiotic karyotypes and structure of testes of nineteen species of jumping-lice (Hemiptera, Psylloidea) from South Africa.

The karyotypes of 19 species of Psylloidea from South Africa belonging to subfamilies Paurocephalinae, Euphyllurinae, Diaphorininae, Euphalerinae, Acizziinae, Ciriacreminae (Psyllidae), Calophyinae (Calophyidae) and Triozinae (Triozidae) were studied for the first time. In 16 species the modal diploid number of chromosomes was found to be 2n=24+X, while 3 species have other chromosome numbers. In Colophorina sp. the chromosomal set consists of 2n=22+X while in Peripsyllopsis speciosa 2n=8+X; the latter being one of the lowest numbers of chromosomes described in psyllids so far. On the other hand, Pauropsylla tricheata is the first species characterized by a chromosomal number higher than the modal one, 2n=26+X. The male gonads of 18 species were described. In 15 of these each testes consisted of two follicles and spermatocystes were arranged in one row. This structure is typical for the majority ofpsyllid species. Polymorphism in the number of testicular follicles in Calophya shini (2-3 follicles) was revealed. In two species, Trioza carvalhoi and T. thibae, each testis consists of a single follicle with spermatocystes arranged in two rows.