Desempenho do fungo Beaveria bassiana (Bals.) Vuill. e do óleo de mamona para controle de Plutella xylostella (L.) (Lepidoptera : Plitellidae)

Abstract

The diamondback moth (DBM), Plutella xylostella (L.) (Lep.: Plutellidae) is considered the most important pest of brassicas productive systems. Due to the high use of pesticides for DBM control, alternative methods to be applied against DBM are necessary. The use of the enthomopathogenic fungus Beauveria bassiana (Bals.) Vuill. and vegetable oils present as promising alternatives to control DBM. Thus, 17 isolates of B. bassiana were studied aiming to select isolates to be used for DBM control. The commercial formulation Boveril® WP (isolate ESALQ-PL63) was also included in the bioassays. Among the evaluated isolates, the isolates CCA/UFES-4, 18, 31 e 35 were selected because they caused mortality confirmed for 2nd-instar larvae greater than 90%. The standard isolate ESALQ-447 and the commercial formulation (Boveril® WP) had similar results and were also selected. In addition, the isolates CCA/UFES-4, 18, 31, ESALQ-447 and Boveril® WP were considered efficient for DBM control based on the lethal concentrations LC50-values. The castor bean oil has its efficacy and stability evaluated, as its compatibility with B. bassiana upon P. xylostella as well. The castor bean oil 1-d old caused53.9% mortality for P. xylostella. The insecticidal activities, however, were unstable over timewhich requires further studies. The results also indicate compatibility between the oil of castor bean and B. bassiana.