Toxicity of Schinus molle L. (Anacardiaceae) on four biological control agents of agriculture pest in Peru.
Schinus molle L. (Anacardiaceae) "pepper tree" is an ethnobotanical important plant belonging to Andean zone and is used as a botanical insecticidal agent for agricultural pest control. The ecotoxicological effects of aqueous extracts of the pepper tree on the following four non-target organisms were evaluated: Ceraeochrysa cincta (Schneider) (Neuroptera: Chrysopidae) eggs and firstinstar larvae, Chrysoperla asoralis (Bank) (Neuroptera: Chrysopidae) eggs and first-instar larvae, Telenomus remus Nixon (Scelionidae: Hymenoptera) adults, and Orius insidiosus Say (Anthocoridae: Hemiptera) adults. Five concentrations with increasing amounts of an aqueous extract from S. molle leaves (w/v) were employed: 1.5%, 2.5%, 5%, 10% and 20%. The parameters of acute toxicity employed were the lethal concentration (LC50) and the effective concentration (EC50). The following sequence in decresing order of ecotoxicity in terms of EC50/LC50 were found: C. cincta larval mortality (LC50 at 48 h=3.7%) > not hatched C. cincta eggs (EC50=5.1%) > O. insidiosus adults (LC50 at 48 h=14.2%) > C. asoralis larval mortality (LC50 at 48 h=32.2%) > not hatched C. asoralis eggs (EC50=34.3%) > T. remus adults (LC50 a 48 h=40.9%). Potential ecological risks of employing this botanical insecticide in Peruvian agroecosystems are discussed. A list of all eukaryotic species with toxicity and repellence of the pepper tree evaluated is included.