EFFECT OF FORMULATING OF BEAUVERIA BASSIANA CONIDIA ON THEIR VIABILITY AND PATHOGENICITY TO THE ONION THRIPS, THRIPS TABACI LIND. (THYSANOPTERA: THRIPIDAE)

摘要

The wettable powder was prepared on the basis of aerial conidia of two isolates of the entomopathognic fungus, Beauveria bassiana. Viability and pathogenicity of conidia products were evaluated against the second-instar larva of Thrips tabaci in four cases; Conidial-product Maintained in Refrigerator (CMR), Conidial-product Maintained in Laboratory (CML), New Formulated Conidia (NFC) and New Conidia without formulation (NC). Analysis of corrected seven-day total mortality data revealed that there were significant differences among these product-cases in their pathogenicity to thrips larvae. Recorded mortality rates for CMR, CML, NFC and NC showed that the pathogenicity of CML was lower compared to three other cases for both isolates. In the next step, inorganic salts (MgCl2, NH4PO4, KH2PO4, MgSO4 and NaCl) were added at a rate of 0.1 M into the both CMR and CML products. Bioassay results indicated that caused total mortality of thrips larvae increased with adding of salts. Our results showed that applied carriers and salts have positively effected preserving of conidia viability and pathogenicity to the second-instar larva of the onion thrips.