Toxicity of aqueous, ethanolic and hexanic extracts of Annona muricata, Minthostachys mollis, Lupinus mutabilis, and Chenopodium quinoa against Tetranychus urticae and Chrysoperla externa

The assessment of the compatibility of plant extracts that have insecticidal properties with pest biological control is essential for the development in integrated pest management strategies. Toxicity of aqueous, ethanolic and hexanic extracts of leaves of Minthostachys mollis (Kunth) Griseb, "muña", and seeds of Annona muricata L. "soursop", Lupinus mutabilis Sweet "tarwi" and Chenopodium quinoa Willd "quinua" were evaluated against adult females of the two-spotted spider mite Tetranychus urticae Koch, 1836, and first instar larvae of green lacewing Chrysoperla externaHagen, 1861. The extracts were applied at concentrations of 10 and 20% with exposure periods of 24 and 72 h. The parameters of toxicity were observed in the NOEC (no observed effect concentration) and LOEC (lowest observed effect concentration) values. Both the aqueous extract of M. mollis and the ethanolic extract of C. quinoa at a concentration of 20% resulted in mortality rates of 28.9 and 29.6% of T. urticae, respectively. The ethanol extract of M. mollis recorded the highest toxicity against C. externa of all extracts evaluated after a 72 h-exposure, with a mortality of 75.7%. According to the RCRS (relative quotient risk of selectivity) obtained at 48 h of exposure, the aqueous extracts did not show toxicity against C. externa. The aqueous M. mollis extract and C. quinoa ethanolic extract at a concentration of 20% could be used in an integrated T. urticae management program.