Susceptibilidad de Plutella xylostella (L.) a extractos acuosos de hojas de sauce llorón y eucalipto, bajo condiciones in vitro.

Abstract

The objective of this research was to evaluate the toxicity of two plant extracts on second instar larvae of Plutella xylostella (L.), under laboratory conditions. For the treatments, the leaf extracts were used at concentrations of (100,000mg/L), (75,000mg/L), (50,000mg/L) and (25,000mg/L) and a control which did not have any type of concentration. Completely randomized experimental design, for the two extracts; each with five concentrations and each concentration with 5 replicates and each replicate with five P. xylostella larvae. To obtain the mortality of the larvae or the emergence of moth adults, starting the observations every 12 hours during the course of the days. The data, analyzed by means of the SPSS Software and Duncan tests to determine significant differences between the treatments. To calculate the LC50, the concentrations were transformed to log10 and the mortalities to Probit, and with the accumulated mortalities of the hour of death, the TL50 was found, by means of Regression Analysis. It was obtained that the concentration of 100,000mg/L of aqueous extracts of willow leaves caused 100% of larvae with significant differences; the concentration 100,000mg/L of Eucalyptus extracts with 80% mortality; with significant differences with the other concentrations. The LC50 determined were for Willow 46.250mg/L, for Eucalyptus 76.910mg/L, to kill 50% of the larvae population of the bioassay. The TL50 for the Willow extracts in its concentration of 100,000mg/L was 61 hours, for the Eucalyptus extracts it was 102 hours.