[Determining of new karyotypes: value of a statistical method].

For the authors, Ectemnorrhininae (coleoptera, curculionidae) from Southern Indian Ocean islands constitute the subject of systematic karyological studies, in order to get further information as to the phylogeny of this group of insects. A previous study had been carried out about 3 different species, Ectemnorrhinus drygalskii, E. viridis and Dusmoecetes richtersi, through direct observation of the only few mitotic metaphase plates, completely isolated from each other, which could be found in adult testis squashes. But a new sort of technique is now available, and which involves a program of data statistical analysis, allowing the sorting out of objects which are characterized by 2 different parameters (in this case, the objects are chromosomes, defined by their length and centromeric index). So that almost all chromosomes can be fully examined in a given preparation, and this can be done in a standardized manner. Applying these new principles, a new determination of the mean values of the parameters characterizing the different chromosomes of the same 3 species is now being worked out. These values will be more accurently determined, and it will then be possible to compare such values, more efficiently, with those of other species of the same group when determined according to the same principles.