Chromosome numbers of two sucking louse species (Insecta, Phthiraptera, Anoplura)

Sucking and chewing, or biting lice !/ Anoplura and Mallophaga (Phthiraptera) !/ are highly exceptional insects in respect to their chromosome systems. Representatives of these groups display holocentric chromosomes and achiasmatic male meiosis. In addition, spermatogenesis is of unique type with several mitotic divisions after the first meiotic division resulting in the formation of cysts with functional and nonfunctional ‘‘tertiary spermatids’’ (TOMBESI and PAPESCHI 1993; TOMBESI et al. 1999). The numberof ‘‘tertiary spermatids’’ in a cyst, 64 or 128, is considered as a species specific character (TOMBESI and PAPESCHI 1993). So far, only few cytogenetic studies on Phthiraptera have been carried out, and only 7 species of Anoplura and 6 species of Mallophaga have been karyotyped (TOMBESI and PAPESCHI 1993). In this study, we represent the first data on karyotypes and spermiogenesis of two anopluran species, Polyplax serrata Burm. (Polyplacidae) and Hoplopleura sp. (Hoplopleuridae).