BIOLOGICAL ACTIVITY OF Bacillus thuringiensis CULTURE SUPERNATANT ON Bemisia tabaci AND ITS PARASITOID Eretmocerus eremicus

Abstract

<p>The effects of <em>Bacillus thuringiensis</em> culture supernatants and their derived products were evaluated on whitefly<em> Bemisia tabaci</em> and its parasitoid <em>Eretmocerus eremicus</em>. Evaluated variables on <em>B. tabaci</em> included adult repellence, oviposition deterrence and nymphal mortality. The most active products were evaluated on mortality of <em>E. eremicus</em>. Residual solid of strain ITCBT62 supernatant showed significant effects on adult repellence (RI, 0.42) and oviposition deterrence (ODI, -70.1). Residual solid of strain ITCBT62 supernatant and ethanol extract of strain ITCBT61 supernatant caused higher mortality of <em>B. tabaci</em> nymphs (53.8 % and 51.2 %, respectively). None of these supernatant derived products had toxic effects on the parasitoid <em>E. eremicus</em>. The analysis of ethanol extract of strain ITCBT61 supernatant by liquid chromatography/high resolution mass spectrometry (LC-HRMS) showed the presence of various compounds, with one particularly abundant metabolite of molecular formula C<sub>15</sub>H<sub>20</sub>N<sub>2</sub>O, which has not been previously reported as product of the liquid culture of <em>B. thuringiensis</em>.</p>