Toxicity of the seed organic extract of Annona muricata L. on Tetranychus evansi Baker & Pritchard (Acari: Tetranychidae) in tomato plants

Abstract

The aim of this study was to evaluate the toxicity of the seed organic extract of Annona muricata L. (Annonaceae) against nymphs and adult females of Tetranychus evansi Baker & Pritchard (Acari: Tetranychidae) on tomato leaves (Lycopersicon esculentum Mill. (Solanaceae)). Experimental design was completely randomized in a factorial scheme (3x5), consisting in three time periods of mortality evaluation (24, 48 and 72 hours), five concentrations of A. muricata seed organic extract (0.0; 0.5; 1.0; 2.0 and 5.0%) and five replications. For the immature forms, each replicate comprised ten protonymphs; for the adult stage, it comprised ten adult females. The effect of the extracts was assessed by direct observation of mortality of immature individuals and adult females of T. evansi for 24, 48 and 72 hours. The results were subjected to regression analysis. In protonymphs and adult females, after 24 hours application of the A. muricata seed extract at concentration 5.0%, a mean efficiency of 98% mite mortality was reached. Concentration 5.0% of the organic extract was capable of causing 100% nymph mortality after 48 hours. Such mortality rate was found among the adults, after the same period, from concentration 1.0% on of the A. muricata extract.