Efeito dos óleos essenciais e de seus compostos majoritários sobre parâmetros biológicos, nutricionais e celular de Spodoptera frugiperda (Lepidoptera: Noctuidae)

Abstract

The study had the following objectives: 1. To test the oil action of Eucalyptus staigeriana F., Ocimum gratissimum L. and Foeniculum vulgare Mill. by contact topic at sublethal doses on biological and reproductive parameters of Spodopera Frugiperda (J.E. Smith); 2. To determine the chemical composition and insecticidal activity of the oils of F. vulgare, O. basilicum L., E. staigeriana, Eucalyptus citriodora Hook, O. gratissimum and their major compounds limonene, trans-anethole, citronellal and linalool on mortality of S. frugiperda and 3. To evaluate the effects of compounds limonene, trans-anethole and limonene+trans-anethole on nutrition, reproduction and testicular apoptosis of this pest. The results showed that the oils of E.staigeriana and F.vulgare at LD20 and LD40 interfered on the biology of S. frugiperda. However, O. gratissimum presented a better result, changing many biological and reproductive parameters in all LD. Chromatographic analysis of the oils showed that the most commonly found were limonene, trans-anethole and methyl chavicol. All oils showed an insecticidal activity, but the highest activity was obtained from trans-anethole with an LD50 of 0.027 mg/g insect, obtaining a toxicity ratio of 1194.07, followed of the oils that presented the substance in the constitution. All treatments reduced the amount of lipids, protein, total sugars and glycogen when compared to the control. However, the most significant result was obtained with the association, except that glycogen did not differ between treatments. All treatments reduced the egg number, oviposition period and adult longevity, when compared to the control. There was no change in the pre-oviposition and post-oviposition parameters. The testicles of the treated larvae with the combination of trans-anethole + limonene and isolated limonene showed apoptosis. It was concluded all oils tested and composed of trans-anethole isolated or associated with limonene present promising results in the control of this important pest.