Effect of insecticides on aphids and beneficial insects of pecan in the Comarca Lagunera

Abstract

Pecan (Carya illinoinensis) is a crop of high economic importance in northern Mexico, whose productivity is limited by the aphid complex that reduces photosynthesis, weakens trees, and decreases yield. In addition, the indiscriminate use of insecticides may negatively affect natural enemies and disrupt ecological balance. In this context, the objective of this study was to evaluate the efficacy of conventional and biorational insecticides for aphid control and to determine their effects on associated beneficial insects. Four field trials were conducted in orchards of the Comarca Lagunera with no prior insecticide applications, using a completely randomized design with four replications, evaluating different products, doses, and plant extracts. Aphid and predator densities were quantified before and after application, and efficacy was determined using the Henderson-Tilton formula and analysis of variance (ANOVA). Results showed that sulfoxaflor and flonicamid produced rapid and high reductions in aphid populations, with efficacy ranging from approximately 73 to 98%, whereas several biorational products (neem, pyrethrum, chicalote, and citrus extracts) exhibited moderate to low control (20-70%). In general, selective insecticides maintained stable predator abundances, with few significant differences among treatments. In conclusion, efficacy and selectivity depend on the insecticide used: selective conventional products provided greater population control, while biorational products favored the conservation of beneficial fauna. The integration of selective products into integrated pest management programs allows effective aphid control while conserving natural enemies, contributing to the sustainability of the production system.