The aim of the present study was to follow up the defense reaction of the haemocytes from larvae treated with bacteria and farnesol. The lysozymes are a powerful tool of the humoral defense mechanism. The insecticidal activity of Bacillus thuringiensis and farnesol on the 4th larval instar of Agrotis ipsilon showed a significant dose and time-dependent increase in mortality. The haemocyte population after bacteria and farnesol treatments was morphologically studied and clarified the haemocytes immune response using Scanning Electron Microscopy (SEM). A marked significant increase was observed in the lysozyme activity of control with time. This may be due to the aging process of the larval instar. The lysozyme activity of the haemocytes showed significant increases at 6 and 12 h. However, the activity decreased significantly at 24 to 72 h, reaching nearly half that of the control value 72 h after the larvae were treated with farnesol. The presented results emphasize the importance of the insect haemocytes lysozyme activity which is considered as a safe measure for insect pest control.
Hanan H. Awad , 2012. Effect of Bacillus thuringiensis and Farnesol on Haemocytes Response and Lysozymal Activity of the Black Cut Worm Agrotis ipsilon Larvae. Asian Journal of Biological Sciences, 5: 157-170.