Effect of Extracts and Compounds of Jatropha curcas L. Seeds Against the Fall Armyworm Spodoptera frugiperda

The present study evaluated the biological control of seed extracts and chemical compounds of physic nut, Jatropha curcas through insecticidal and insectistatic activity against the armyworm, Spodoptera frugiperda . Gas chromatography -mass spectrometry analysis showed that major constituents of the hexanic extract were oleic (40.3% 2 mu L extract / 10 ml solvent (v/v)), linoleic (27.3%), and palmitic (15.8%) fatty acids, while the major constituents of the acetonic extract were oleic (47.6%), linoleic (32.8%), and palmitic (14.3%) acids. In an ingestion bioassay with neonate S. frugiperda , the extracts were evaluated at six concentrations (0, 100, 250,1,000, 2,500, and 5,000 ppm). The fatty acid extracts induced a positive relationship where the higher the concentration, the greater the effect on larval and pupal weight, the development of the larvae and pupae, and larval and pupal mortality. Hexanic and acetonic extracts at 5,000 ppm caused 100% larval mortality. The oleic and linoleic fatty acids were further evaluated at (0, 100, 160, 400, 600 and 1,000 ppm). Oleic acid at 600 ppm reduced the weights of the larvae and pupae, as well as increased the mortality of the pupa, while the linoleic acid at 400 ppm reduced the weight larvae and increased mortality larval and pupal. The values of lethal concentrations fifty and ninety (LC50-LC90) of oleic and linoleic acid were 125 - 624 ppm and 199 - 630 ppm, respectively. Extracts and fatty acids from the seeds of J. curcas can be explored as useful alternatives for the control of S. frugiperda .