Preliminary Investigations into the Biological Control of Red Palm Weevil Rhynchophorus ferrugineus by using three isolates of the fungus Lecanicillium (Verticillium) lecanii in Egypt

When the different stages of Red Palm Weevil (RPW) treated with the different three isolates of fungi Lecanicillium (Verticillium) lecanii different concentrations, the LC50 obtained of isolate (1) were, 244 x104, 236 X 104, 207 X 104, 200 X 104, 316 X 104 and 305 X 104 spores / ml for 2nd, 3rd, 4th, 5th, and adult and respectively. , When RPW treated with laboratory isolate (2) of L. lecanii the corresponding LC50 obtained, 210 X 104, 280 X 104, 270 X 104, 267 X 104, 241X 104, 350 X 104, and 321 X 104 spores/ml. , respectively. Results detect that the target insect pests affected by isolate (3) of L. lecanii and isolated L. lecanii and the percentage of larval mortality were significantly increased to 87, 97 % and 88 % after treated with isolated and L. lecanii as compared to 1 % in the control. The percentage of moth hatching were significantly decreased to 9 % as compared to 100 % in the control The result show that the palm weight were significant increase in El-Kassaseen (Ismailia) than in El-Esraa (Nobarya) to 499765.32 kg/ Feddan as compared to 198180.54 kg/ Feddan during season 2012. During season 2012 the yield loss obtained 56 and 60 % in El-Esraa (Nobarya) and El-Kassaseen (Ismailia) which decreased to 22 and 22 % in borth corresponding regions. The same results obtained during season 2013. The yield weight were significantly increased to 5875 34.35 Kg/feddan in El-Esraa (Nobarya) as compared to 1999 36.81 Kg/ feddan in the control. In El-Kassaseen (Ismailia), the yields were significantly increased to 599765.31 Kg/ feddan as compared to 179180.44 Kg/ feddan in the control. The yield loss ranged between 70 and 35 %.