Pathogenicity of Beauveria bassiana and Lecanicillium muscariumon cotton whitefly(Bemisia tabaci (Homoptera: Aleyrodidae)) in simultaneously use

Pathogenicity of Beauveria bassiana strain DEBI001, Lecanicillium muscarium strain DAOM 198499 and their combination was investigated on 2nd nymphs and adults of B. tabaci in lab condition (in a germinator, 23±1ºC, 95±5% and 16:8 L:D). Five concentrations of each fungi were sprayed on undersides of young eggplant leaves that involved 2nd nymphs. Experiments were carried out on adults with the same concentrations in two methods of spraying: Direct spraying on adults, and indirect spraying on plant leaves. LC50 values of the B. bassiana, L. muscarium and their combination on 2nd nymphs was 4.4×105, 1.8×105 and 7.9×105 conidia/ml, respectively. Results showed that LT50 values for different doses (106, 107 and 108 conidia/ml) of B. bassiana were 8.3, 6 and 4.8 days; for L. munmscarium were equal to 7.2, 5.5 and 3.9 days and 6.7, 5.1 and 4 days for their combination. Adults in indirect methods showed high mortality than control. The highest mortality by B. bassiana were %89.33; and %96.25; While it was % 78.33;and %93.75 by L. muscarium, immediately and 5 days after spraying respectively. Adult mortality rate was lower in direct spraying method than indirect application ( %51.1 by B.bassiana and %38.32 by L. muscarium for 108 conidia/ml).