Abstract
The tropical bush cricket Eneoptera surinamensis (De Geer, 1773) shows a peculiar karyotype with 2n = 9 for males, and 2n = 10 for females, with X1X2Y♂ sex mechanism systems whose origin remains unclear, probably arisen by a two-step chromosome rearrangements, including an X acrocentric and two pair of autosomal acrocentric chromosomes (Mesa & Bran 1964; Ferreira & Cella 2006). This sex system contrasts with the less derived X0♂ found in the majority of the Orthoptera species (White 1973; Hewitt 1979).