Persistence of Isaria fumosorosea (Hypocreales: Cordycipitaceae) SFP-198 conidia in corn oil-based suspension.
Long-term persistence of entomopathogenic fungi as biopesticides is a major requirement for successful industrialization. Corn oil carrier was superior in maintaining germination rates of Isaria fumosorosea SFP-198 conidia during exposure to 50°C for 2 h, when compared with other oils, such as soybean oil, cottonseed oil, paraffin oil, and methyl oleate. The corn oil-based conidial suspension (91.6% germination) was also better in this regard than conidial powder (28.4% germination) after 50°C for 8 h. Long-term storage stabilities of corn oil-based conidial suspension and conidial powder at 4 and 25°C for 24 months were investigated, based on the correlation of germination rate with insecticidal activity against greenhouse whiteflies, Trialeurodes vaporariorum. Viability of conidia in corn oil was more than 98.4% for up to 9 months of storage at 25°C, and followed by 23% at 21 months. However, conidial powder had only 34% viability after 3 months of storage at 25°C, after which its viability rapidly decreased. The two conidial preparations stored at 4°C had better viabilities than those at 25°C, showing the same pattern as above. These results indicate that corn oil-based conidial suspension can be used to improve conidial persistence in long-term storage and be further applied to the formulation of other thermo-susceptible biological control agents.
Kim
Jae Su
JS
Entomology Research Laboratory, Department of Plant and Soil Science, University of Vermont, 661 Spear Street, Burlington, VT 05405-0105, USA, jae-su.kim@uvm.edu
Je
Yeon Ho
YH
Woo
En Ok
EO
Park
Jong Sung
JS
D000818:Animals; D003314:Corn Oil; D006999:Hypocreales / Q000302:isolation & purification*; D050296:Microbial Viability; D009036:Moths / Q000382:microbiology; D013172:Spores, Fungal / Q000302:isolation & purification; D016019:Survival Analysis; D013535:Suspensions; D013696:Temperature
D013535:Suspensions; D003314:Corn Oil