Efficiency of entomopathogenic fungi Beauveria bassiana and Verticillium lecanii for biological control of whitefly, Bemisia tabaci

Abstract

A study was conducted under field conditions to evaluate the efficiency of two entomopathogeaic fungi: Beauveria bassiana and Verticillium lecanii to parasitize whitefly nymphs and adults. Results revealed that V. lecanii showed the highest perecentage of parasitism (73.4%) on adults and nymphs on egg plant under field conditions at AL-Nehrawn compared with B. bassiana isolate 1 and 2 (56.7 and 50.4% respectively) after 10- days of treatment. When used conidia suspension of V. lecanii with 0.02% triton caused the highest parasitism (90%) after 10 days of treatment.In a field experiment at AL-Tuwaitha, the results indicated that V. lecanii showed that highest percentage of parasitism (90 and 80.66%) compared with B. bassiana isolate 1 and 2 (68.66, 60 and 53.33, 48%) when used 0.02% triton and 0.2% corn oil resectively after 10 days of treatment . While in a green house experiment , the results showed the use of V. lecanii and B. bassiana isolate 1 together was more effective in parasitizing (90%) than use of either one alone (70.3 and 81% for V. lecanii and B. bassiana isolate 1 respectively) on adults and nymphs after 15 das of treatment . There was a clear reduction in the number of colony forming units (CFU) viability of V. lecanii and B. bassiana isolate 1 and 2 with time of storage, for the fungal viability storage at room temperature was less efficient than storage at 4 0C .