Óleos essenciais de C. Tricolor e ensaios de toxicidade de contato e índices nutricionais em Tribolium Castaneum

Abstract

INTRODUCTION. Regarding the adaptive capacity of plants in the face of environmental factors, the relevance of secondary metabolites in responding to stress conditions stands out. Essential oils (EO), derived from aromatic plants and recognized for their non-toxic properties and volatility, emerge as promising agents in the control of insect pests. GOAL. The focus of this study is on Tribolium castaneum, a pest beetle of stored products, exploring the insecticidal potential of essential oils from the Croton tricolor plant. The central objective is to evaluate the insecticidal and repellent efficacy of essential oils from leaves and branches of Croton tricolor Klotzsch ex Baill against T. castaneum, identifying toxic concentrations and analyzing nutritional indexes of insects after exposure to LD50. METHODOLOGY. The effects of essential oils on the nutritional indices, metabolism and reproduction of T. castaneum were evaluated. The extraction of essential oils was carried out by hydrodistillation, and a contact toxicity bioassay was conducted with different concentrations of essential oils from leaves and branches diluted in acetone. Calculations of nutritional indices, such as Relative Consumption Rate (RCR), Relative Growth Rate (RGR) and Ingested Food Conversion Efficiency (ECI), based on the initial and final weight of insects and wheat flour complemented the evaluation . RESULTS. The RCR results had the highest concentration of OEFCT at 5%, while OERCT at 10%. As for RGR, the 10% concentration was the highest, both for OEFCT and OERCT. And the last index evaluated concentrations of 2.5% and 10%, of the respective OEFCT and OERCT had a higher percentage of ECI. CONCLUSION. The insecticidal efficacy of Croton tricolor essential oils, especially from the branches, highlights their potential as a valuable tool in this context, aligned with an ecologically conscious approach, as an alternative to synthetic chemical insecticides, contributing to sustainable strategies.