Larvicidal and ovicidal activities of Chloroxylon swietenia (Rutaceae) essential oils against Spodoptera litura (Lepidoptera: Noctuidae) and their chemical compositions

Krishnappa K and Elumalai K

Objective: To determine the chemical composition, larvicidal and ovicidal activity of the essential oil from Chloroxylon swietenia (C. swietenia) against lepidopteran pest Spodoptera litura (S. litura). Methods: The plants dry leaves were subjected to hydrodistillation using a modified Clevenger-type apparatus. The composition of the essential oil was analyzed by gas chromatography (GC) and GC mass spectrophotometry. C. swietenia essential oil and major chemical compositions was tested, against 4 th instar larvae of S.litura for 24 h and mortality were recorded at various concentrations(10-250ppm); The 24 h LC50 and LC90 value of C. swietenia oil were determined following probit analysis. C. swietenia essential oil and major chemical compositions was tested, against S.litura eggs for 120 h post treatment and Percentage of egg hatch ability recorded at various concentrations (25-250 ppm). Results: Chemical constituents of Twenty compounds were identified in the oil of C. swietenia compounds representing to 98.95%. The major Chemical compositions in leaves were α-Pinene, limonene, geijerene, pregeijerene and germacrene D. The essential oil exhibited significant larvicidal activity, with 24h LC50 131.20 ppm and LC90 224.68 ppm. The major Chemical compositions larvicidal activity were also tested. The LC50 values of geijerene, limonene, germacrene D, pregeijerene and α-Pinene were LC50 18.31, 20.03, 24.83, 25.23 and 26.35 ppm and LC90 34.77, 38.31, 46.67, 47.27 and 49.78 ppm respectively. The essential oil produced (100% mortality) eggs no hatchability recorded in 200 ppm, however, highest ovicidal activity found in geijerene 125 ppm, This was closely followed by limonene and germacrene D 150 ppm, pregeijerene and α-Pinene had 175 ppm, respectively. Conclusions: Results of this study show that the leaf essential oil of C. swietenia and its five major compositions may be a potent source of natural larvicidal and ovicidal activities against lepidopteran agricultural pest S. litura.

Download PDF: