Insecticidal Activity of Essential Oils of Eucalyptus camaldulensis and Thymus daenensis against Callosobruchus maculatus (Coleoptera: Bruchidae)

This study was determined fumigant toxicity of essential oils from Eucalyptus camaldulensis and Thymus daenensis on Callosobruchus maculatus after exposed to essential oils for 24 h. Essential oils were extracted using hydro distillation by Clevenger apparatus. Experiments were conducted at 27±1oC and 60±5% relative humidity (RH) under dark conditions. Four concentrations of each essential oils were tested in three replicates against adults of Callosobruchus maculatus. Essential oils were analyzed by gas chromatography-mass spectrometry (GC-MS). The results showed that the main compounds of essential oil of Eucalyptus camaldulensis were spathulenol (15.58%) ,ρ-cymene (12.44%), 1,8-cineole (10.50%), ledene (5.23%), α-pinene (2.12%), and β-phellandrene (0.33%). The major compounds in essential oil of Thymus daenensis were characterized as thymol (52.24%), γ-terpine (4.03%), 1, 8-cineole (2.76%), carvacrol (2.21%) and borneol (1.72%). Both essential oils had high fumigant toxicity to adult insects of Callosobruchus maculatus. LC50 Values determined by SPSS 16.0 software. The results showed that LC50 values of essential oil of Eucalyptus camaldulensis and Thymus daenensis were 116.834 and 69.452 (μl/lair) respectively. The results indicated that the high potential of essential oils especially the essential oil of Thymus daenensis have strong effects to control the Callosobruchus maculatus.

callosobruchus maculatus, eucalyptus camaldulensis, thymus daenensis, insecticidial effects, essential oil