Revision of the stick insect genus Leptynia: description of new taxa, speciation mechanism and phylogeography

Leptynia specimens were analyzed by karyotype analysis, mi-tochondrial gene sequencing and SEM of bodies and eggs. Here we describe a new species, Leptynia annaepaulae, and three subspecies of L. attenuata Pantel (L. attenuata attenuata, L. attenuata iberica, L. attenuata algarvica). The phylogeny of the genus Leptynia is congruent with a karyotype trend toward a reduction of chromosome number and the shift from the shared XX/X0 sex chromosome formula to the unusual XX/XY one. Chromosome repatterning appears to occur ahead of ge-netic differentiation, following a chromosome model of clado-genesis. Chromosome and genetic differentiation, in turn, ap-pears to precede morphological distinction, thus realizing a condition of incipient species for most of the Leptynia taxa. Actually, morphological analyses revealed that, only rarel