tailieunhanh - Effect of different spore concentration of Entomopathogenic fungi isolates against mealy bug Maconellicocus hirsutus

Entomopathogenic fungi suppress the diverse group of insect pest such as coleopterans, lepidopterous and sucking pest. Wide spread incidence of Aspergillus niger, Aspergillus flavus and Aspergillus tamarii was observed during extensive and repeated survey covering different agro ecological niches of Dhule, Nandurbar, Jalgaon, Nasik and Beed districts of Maharashtra (India) on insect cadavers infected with fungi. From the insect cadavers the fungal isolates were isolated on PDA media. Out of nineteen samples collected only fifteen samples showed the growth of fungus on DOC 2-50% selective media. Virulence of entomopathogenic fungi isolates against mealy bugs (Maconellicoccus hirsutus) revealed that as the spore concentration increased from 10-3 to 10-9 the insect mortality was decreased. Among all the fifteen isolates the highest insect mortality was recorded at 10-3 spores/ml concentration and the spore dilution of entomopathogenic fungi isolates increased from 10-3 to 10-9 spores/ml the time required for insect mortality was also increased. Among the isolates of entomopathogenic fungi the isolate EPF-14 was the most virulent. Among each isolate, it was observed that as the spore dilution increased the insect mortality decreased. Aspergillus tamarii, A. niger and A. flavus the isolate EPF-7, EPF-14 and EPF-6 were the most virulent, respectively against mealy bugs at 10-3 spores/ml concentration and isolates EPF-1, EPF-2 and EPF-6 were the most virulent isolates respectively against mealy bugs at 10-6 and 10-9 spores/ml concentration. | Effect of different spore concentration of Entomopathogenic fungi isolates against mealy bug Maconellicocus hirsutus