Pathogenicity of some entomopathogenic fungal strains to green peach aphid, Myzus persicae Sulzer (Homoptera: Aphididae)

Abstract

Abstract Pathogenicity of four fungal strains, two of Beauveria bassiana (designated as BB-72 and BB-252), and two of Lecanicillium lecanii (designated as V-4 and CS-625) to green peach aphid, Myzus persicae Sulzer (Homoptera: Aphididae) was assessed. All treatments showed highly significant effects on the mortality of the aphid when applied as filtrate or conidia. The application methods did not have a significant effect on the mortality rate. The overall mortalities caused by both applications were statistically similar. The maximum overall mortality was caused by BB-72, followed by CS-625 in both application methods. On the other hand, (V-4) caused the minimum mortality rate, followed by (BB-252), which was statistically similar to those caused by V-4. The time also had significant effects on aphid mortality rates. The mortality was the minimum after 3 days reaching its maximum after 10 days. As the number of days increased, there was a corresponding increase in the mortality showing a direct relationship between mortality and time. The maximum mean individual mortality of 95% was caused by CS-625, followed by BB-72 (92%) after 10 days with the conidial application. Similarly, the combined effects of the three most virulent fungal strains showed highly significant differences on the mortality of peach aphid. The combination BB-72 + BB-252 showed the highest percent mortality, followed by BB-72 + BB-252 + CS-625. The combinations BB-72 + CS-625 and BB-252 + CS-625 had statistically similar effects of causing aphid mortality.

Keywords

• Green peach aphid
• Entomopathogenic fungal strains
• Pathogenicity, biocontrol
• Mortality