Selection of isolates of Beauveria bassiana pathogenic to cotton boll weevil

The objective of this work was to screen pathogenic isolates of Beauveria b assiana (Balsamo) Vuillemin from different hosts and geographic regions, pa thogenic to the cotton boil weevil. Twelve isolates were evaluated. Isolate s originally obtained from bell weevil showed low pathogenicity against thi s host. Insect mortality began on the second day after inoculation by funga l suspension, ranging from 15% to 83%, with a TL50 of 5.30 to 11.06 days. V ariability among isolates concerning conidial germination in artificial cul ture medium was verified, and TG,, did not correlate with pathogenicity. On e of the most virulent isolates of B. bassiana against cotton bell weevil i s CG138.