Abstract:
The study was conducted in Microbiology Laboratory the Environment and Natural Resources and Desertification Research Institute (ENRDRI), Khartoum. The study was focused on the isolation and indentation of different races of entomopathogenic fungi B. bassiana. Then the experiments were conducted to evaluate the effect of different races on the larval mortality of T .germanium which reared on wheat seeds.
Four races of B. bassiana were isolated and identified. The races were E,M,H, and A).Then the experiment evaluate their effect on larval mortality of Khapra beetle by dusting method in 14 days. The results showed that the two races E and M are the best compared to the others regarding their effect on mortality. The mortality values were100% for race E and (90% for race M).
The two best races (E and M) were evaluated to determine their effect on mortality of Khapra beetle larvae by dipping method during 14 days. The values of LC50and LT50 were calculated using Probit analysis method. The results showed that race M is the best in controlling the insect as it caused mortality of 90% with concentration 1010 compared with race E which achieved mortality of 80% with concentration 1010 .The value of LC50 for race M was 1.54108× compared to 2.31 1010×for race E.
According to these results it was concluded that, the races of the fungus B.bassiana considered as effective and environmentally safe in controlling Khapra beetle larva study. Moreover, the study recommended that race M has to be used by dipping method and race E by dusting method.
