The B chromosome polymorphism of the grasshopper Eyprepocnemis plorans in North Africa. I. B variants and frequency

Polymorphism for B chromosomes has been detected in all nine populations of the grasshopper Eyprepocnemis plorans ssp. plorans sampled in Morocco. The most frequent B chromosome in all populations showed a C-banding pattern a nd size similar to those of the B-1 variant found in the Iberian Peninsula. In addition. other B chromosome variants (B-liso1, B-liso2, B-ld1, B-ldi1, B-3 and B-ldd1) were discovered in these populations, although at a very l ow frequency, No significant differences in B chromosome frequency were Fou nd either in the nine populations or, for some of them, in up to three cons ecutive years. These results are discussed in the light of current hypothes es on the evolution of this B chromosome polymorphism in the Iberian Penins ula.