Merçot H, Charlat S (2004) Wolbachia infections in Drosophila melanogaster and D. simulans: polymorphism and levels of cytoplasmic incompatibility. In: Drosophila melanogaster, Drosophila simulans: So Similar, So Different Contemporary issues in genetics and evolution. (eds Capy P, Gibert P, Boussy I), pp. 51–59. Springer Netherlands, Dordrecht.