GENETIC DIVERSITY OF BEAUVERIA-BASSIANA AND RELATEDNESS TO HOST INSECT RANGE

Thirty-eight strains of the entomopathogenic Beauveria bassiana, isola ted from diverse species of Lepidoptera (Pyralidae) or Coleoptera (Cur culionidae, Chrysomelidae, and Scolytidae) from various geographical s ites, were examined by RFLP and RAPD analyses. Similar groupings were recovered from both approaches and these showed clear relationships be tween the population structure of B. bassiana and some defined host sp ecies. Strains isolated from members of the Pyralidae were recovered a s two main groups, one group consisted of all strains isolated from Os trinia irrespective of their origin. The second group consisted primar ily of strains isolated from Diatraea in Cuba. All strains isolated fr om the curculionid genus Sitoma clustered as a single distinct group. separated from strains from other curculionids. In contrast, strains i solated from the pyralid genus Maliarpha, and the coleopteran Chrysome lidae, gave heterogenous patterns and were not recovered as distinct g roups. Groups from duster analysis and nonhierarchic ordination method s were compared and the relative merits of the different grouping stra tegies are discussed.