RESUMO
This paper presents the first record of B chromosomes in some adult male individuals of the African pest grasshopper Taphronota thaelephora collected from Balepa - Mbouda in the Western Province of Cameroon. Of the twenty individuals examined; thirteen had the characteristic Pyrgomorphidae karyotype of 2N= 19(18A+XO) while the remaining seven had a diploid chromosome number of 2N= 20(18A+XO+1B) indicating the presence of a single B chromosome. The B chromosome in this population was short; acrocentric in morphology and stained to the same intensity as the autosomes throughout meiosis. It did not associate with any chromosome in meiosis. In some cells it migrated to the same pole as the X-chromosome while in other cells it migrated to the pole opposite to that of the X-chromosome indicating irregular behaviour in meiosis. The presence of the B chromosome did not affect chiasma frequency in the species