Efficacy of essential oil of Lavandula angustifolia on mortality and physiological parameters of diamondback moth, Plutella xylustella (Lep.: Pyralidae)

Efficacy of the essential oil of the plant species Lavandula angustifolia on the mortality, physiology and biochemistry of diamondback moth, Plutella xylustella L., was studied under laboratory conditions (24 ± 2ºC, 75 ± 5% R.H. and 16 L: 8 D hours). The LC10, LC30 and LC50 values of the essential oil were estimated as 0.0857%, 0.270% and 0.599% (V/V), respectively. The repellency effect for the LC10 and LC30 concentrations on third instar larvae were 19.2 ± 3.61 and 34.29 ± 4.87, respectively. The approximate digestibility (AD), efficiency of conversion of ingested food (ECI), efficiency of conversion of digested food (ECD), relative growth rate (RGR) and relative consumption rate (RCR) for the treated larvae in three days showed significant differences compared with the controls. The effectiveness of plant essential oils on digestive enzymes, total protein, triglycerides, alkaline phosphatase, protease, lipase, alfa amylase, glutathione S-transferase and esterase were also significantly different. Our finding suggests that the essential oil of L. angustifolia can be efficiently used as a botanical insecticide.