An unexpected sex chromosome mechanism in a South African mantid Polyspilota aeriginosa Goeza

SUMMARY

A male Polyspilota aeriginosa from the Eastern Transvaal lowveld, was studied cytogenetically. A chromosome number of 2n ♂ =28(X¹X²Y¹Y²) was found to occur. This unique sex chromosome mechanism has not been reported previously in the Mantidae. The chromosome number of 2n = 28 was also unexpected since almost all other members of the subfamily Mantinae show 2n ♂ =27 (X¹X²Y). This makes it very difficult to explain the origin of the sex chromosome mechanism of this individual. Some possible mechanisms are discussed.