ABSTRACT
The entomopathogenic fungus Beauveria bassiana has been used in the control of many pests affecting important crops in Brazil. It is pathogenic to the sugar cane borer Diatraea saccharalis which is considered one of the major pests of this crop. The objective of this work was to evaluate the effect of the concentrations: 5 x 106, 1 x 107, 5 x 107, 1 x 108 and 5 x 108 conidia/mL of the IBCB 66 strain of Beauveria bassiana to this borer. With the support of a Potter tower 1 mL of the fungus suspension was applied on the larvae of D. saccharalis that later were put indivudualy in tubes with a piece of young sugar cane. These tubes were kept in a climated room at 25.5 ± 0.5º C and RH around 70% and the evaluations of mortality were done daily until the sixth day. The dead larvae were put in humid chamber in order to confirm their death by the entomopathogen. The fungus was pathogenic to D. saccharalis in all the concentrations evatuated and the LC50 for the sixth day was determined in 1.58 x 107 con./mL.
KEY WORDS
Beauveria bassiana
;
Diatraea saccharalis
; pathogenicity; microbial control