Karyological studies of mediterranean stick-insects belonging to the genera Clonopsis and Leptynia (Insecta Phasmatodea)

SUMMARY

Karyotypes of three species of Clonopsis and of various populations of Leptynia hispanica and L. attenuata complexes were analyzed. The taxonomic status of the latter complexes is still uncertain. These genera include bisexual and parthenogenetic polyploid species and populations. The chromosomal numbers are: 2n = 32 in bisexual C. algerica, 2n = 22 in bisexual C. maroccana, 3n = 54 in telytokous C. gallica, 2n = 38 in bisexual Leptynia hispanica, 3n = 57 in telytokous triploid populations of L. hispanica, 4n = 76 in telytokous tetraploid populations of the same complex, 2n = 36 in a bisexual taxon of L. attenuata complex, 2n = 38 in an other bisexual taxon and 4n = 76 in a parthenogenetic tetraploid taxon of the same complex. All the karyotypes are described. It is postulated that pericentric inversions and centric fusions have played a relevant role in chromosomal evolution of these genera. Because hybridization is the more frequent mode of speciation in these stick-insects, the polyploidy, connected with parthenogenetic reproduction is probably an allopolyploidy.