Lethal and sublethal effects of hexane extract and microencapsulation of Annona squamosa L. (Annonaceae) seeds to Tetranychus urticae (Koch, 1836) (Acari: Tetranychidae)

Abstract

ABSTRACTPest mites that survive the exposure of acaricides can suffer from sublethal effects. The objective of this work was to evaluate the sublethal toxicity of the ovicidal, repellent, and residual effects as well as instantaneous population growth rate (ri), of A. squamosa hexane extract and microencapsulation of A. squamosa seeds to Tetranychus urticae (Koch, 1836) (Acari: Tetranychidae). The microencapsulation in LC99 had the lowest egg viability at 7.50 ± 2.70%. The repellent effect was observed from LC95 and LC50 for extract and microencapsulation, respectively. The instantaneous rate of population growth for both products decreased with increasing concentrations. Efficient residual effect was observed for LC99 up to 8 and 15 days after spraying (DAS), for the microencapsulation and extract, respectively, in greenhouse. For the field experiments 1 and 2, the microencapsulation at LC99 was efficient up to 6 and 9 DAS, respectively, and the hexane extract until 7 and 10 DAS. Thus, A. squamosa hexane extract and the microencapsulation extract cause sublethal effects to T. urticae and can be used to manage this pest.