Insecticidal effect of Jatropha curcas L. Oil on Spodoptera frugiperda (Smith) (Lepidoptera:Noctuidae)

Abstract

The study was undertaken to contribute to the sustainable management of Spodoptera frugiperda Smith on maize. It aims to evaluate the insecticidal efficacy of Jatropha curcas L. oil on S. frugiperda larvae. Two concentrations of J. curcas oil (10 and 20ml.l-1) were tested by ingestion on the six larval stages of S. frugiperda grouped into (L1-2 (3-5 days of age); L3-4 (6-8 days of age); L5-6 (>10 days of age)). The insecticidal efficacy of the oil was determined in the laboratory and the phytosanitary protection tests on maize were carried out in the field. In the laboratory, the concentration of 10 ml.l-1 with/without emulsifier caused a mortality rate of (87-92%) at stage L1-2, (51-58%) at stage L3-4, and (57- 68%) at L5-6 stage after 72 hours of ingestion. Concentration of 20 ml.l-1 caused over 70% mortality whether applied with or without an emulsifier at all stages. Adult emergence was nil for L1-2 stages at 20 ml.l-1 and <10% for the other stages. Plots subjected to jatropha oil treatments (2l.ha-1 and 4l.ha-1 with or without emulsifier) were less infested like the plots treated with Emamectine benzoate (Emacot) compared to control plots untreated. The present results indicated that jatropha oil has insecticidal potential against S. frugiperda.