Of special interest for basic research is how chromosomal evolution and regulation work during parthenogenetic and clonal reproduction are typical for many species of stick insects. In some species, parthenogenetic populations may be observed in parallel to sexual populations ; how this is regulated and if and how they interact is still not known. Additionally, it needs to be considered that parthenogenetic reproduction may lead to diversity and selection of the most adapted clones. This has been shown by the breeding of stick insects over generations: some cultures reproduced successfully and stayed phenotypically unchanged, while others underwent unexpected changes. For example, changes in normally red wing color to white or pink in Peruphasma schultei in captivity have been reported recently . In a parthenogenetic lineage, new genetic and karyotypic variants normally do not derive from the recombination of the existing genetic and karyotypic elements within the population. Considering the possibility of different egg maturation mechanisms, as observed in Clonopsis gallica, restricted recombination may be possible also here . Still, in most cases parthenogenetic reproduction can be suggested to diminish possible genetic diversity, reducing genotypic and phenotypic variability for natural selection. It should be expected that this kind of evolutionary scenario leads to genomes adapted to long parthenogenetic reproduction, and possibly an accumulation of harmful mutations. In this context, structural chromosome re-patterning, such as fissions, translocations, and polyploidy have been observed . Thus, one major adaptation of parthenogenetic strains is probably whole or segmental polyploidy or amplification of some genomic elements, or both. In alternate or intermixing parthenogenetic and sexual reproducing populations, sexual reproduction can address problems in correct chromosome pairing and recombination during meiosis. This could require special genome and karyotype organization, preventing multivalent formation and ensuring genetic balance.