Effects of two different isolates of entomopathogen fungus, beauveria bassiana (Balsamo) vuillemin (Ascomycota: Hypocreales) on myzus persicae sulzer (Hemiptera: Aphididae)

The study aimed to determine the effectivity of LD.2016 and M6-4 isolates of entomopathogen Beauveria bassiana on Myzus persicae Sulzer (Hemiptera: Aphididae). In this context, the doses of 106, 107 and 108 conidi.ml-1 for isolates were used. Experiments for each dose and control group were conducted on 50 individuals. The offsprings were checked daily and body wastes were removed from petri dishes. The aphids reached the 2nd or 3rd nymph period were dipped in the spore suspension of the entomopathogen for five seconds. To calculate the mortality on the 3rd, 5th, 7th and 9th days after the application the living individuals were recorded. The daily controls were lasted until all individuals were died and some parameters of life table were determined. Based on the data obtained, it is determined that as the dose increases, the mortality rates also increase. The highest effects of both isolates were found at the doses of 108 conidi.ml-1. LT50 values of LD.2016 and M6-4 isolates were 6.19 and 5.5 days, respectively at 108 conidi.ml-1 dose. The rm values of the individuals exposed to the doses of 106, 107 and 108 conidi.ml-1 were calculated as 0.340, 0.352, and 0.337 females/females/day, respectively for the LD.2016 isolate and 0.292, 0.263, and 0.268 females/females/day for the M6-4 isolate. The value was 0.280 females/females/day for the control individuals. While the dose was increased, the values of lx and mx parameters were decreased, too. Besides, the Weibull and Enkegaard models applied on the lx and mx values were fitted on the data obtained from both isolates. As a result, it is thought that the isolates of entomopathogen B. bassiana, less harmful to humans and the environment, can be used as a biological control agent in the controlling of the pest.