ABSTRACT
Toxicity of pesticides on natural enemies of agricultural pests

Robinson Vargas M.1 y Alejandrina Ubillo F.1
 

A simple, precise and economic method was developed to evaluate the residual toxicity of a pesticide to natural enemies. The highest commercial dose recommended by the manufacturer was sprayed on Petri dishes using a Potter tower or immersing the dishes in a diluted solution of the pesticide. The relative toxicity of a pesticide was compared using mean lethal time (TL50's) in 4 categories. The first category comprised the most toxic responses between 0h< TL50< 2h, and included: Azinphosmethyl on Neoseiulus chilenensis (Dosse) and Phytoseiulus persimilis Athias-Henriot; Chlorfenvinphos on Amitus spiniferus (Brèthes), Lysiphlebus testaceipes (Cresson), Pauridia peregrina Timberlake and Scutellista caerulea (Fonscolombe); Chlorpyrifos on A. spiniferus, L. testaceipes, Metaphycus flavus (Howard); P. peregrina and P. persimilis; Diazinon on M. flavus and P. persimilis; Esfenvalerate on P. persimilis; Formetanate on Orius insidiosus (Say); Imidacloprid on A. spiniferus, L. testaceipes, M. flavus, P. peregrina, S. caerulea; Methamidophos on O. insidiosus; Methomyl on O. insidiosus; Permethrin on N. chilenensis and P. persimilis. The second category consisted of TL50's between 2h< TL50 < 5h and included: Chlorpyrifos on S. caerulea. The third category consisted of TL50's between 5h< TL50< 24h and included: Copper oxychloride on A. spiniferus and L. testaceipes. The fourth category consisted of TL50's after 24h>TL50 and included: Copper oxychloride on S. caerulea. The results of this study agree with those obtained by other researchers who used methods accepted by the International Organization for Biological Control of Noxious Animals and Plants (

Keywords: selectivity, ecotoxicology, integrated pest management, beneficial insects, residual toxicity.
1 Instituto de Investigaciones Agropecuarias, Centro Experimental de Entomología La Cruz. Casilla 3, La Cruz, Chile. E-email: rvargas@inia.cl.