ENZYMATIC VARIABILITY IN 3 SPECIES OF SITOPHILUS (COLEOPTERA, CURCULIONIDAE)

Electrophoretic analysis of esterases was carried out on a total of 37 strains of Sitophilus oryzae, S. zeamais and S. granarius. Polymorphi sm rate was higher in S. zeamais than in the two other species. Estera se characters allow the three species to be distinguished and confirm that S. oryzae and S. zeamais are doser to each other than to S. grana rius. They also allow differentiation between populations of the same species, but do not indicate the geographical origin of all population s. A high mixture of populations due to the transport of cereals all o ver the world could explain such a result.