Abstract: The potential of wild-type and recombinant Autographa californica multiple nucleopolyhedrovirus (AcMNPV) and their mixtures with Bacillus thuringiensis (Bt) in the biological control of Lobesia botrana larvae were determined. The daily mortality rates of larvae infected with WT (wild type AcMNPV), WT-31 (AcMNPV carrying Cydia pomonella granulovirus (CpGV) orf31) and WT^gp64-31 (AcMNPV lacking gp64 gene and carrying CpGV orf31) showed a gradual but slow increase. The corrected mortality rates with WT (80.36 %) and WT-31 (71.43%) were not significantly different, but were significantly higher than that with WT^gp64-31 (58.93%). The LC₅₀and LC₉₀ of WT-31 mixed with 1000 IU/mL Bt were 1.66×10³ PIB/mL and 3.07×10⁵ PIB/mL, respectively. The LT₅₀ of WT-31 at 10⁴ PIB/mL and 10⁵ PIB/mL was 5.67 d and 4.24 d, respectively, and the LT₉₀ was 11.62 d and 9.33 d, respectively. The results show that AcMNPV can infect L. botrana and lower concentration of Bt can significantly promote the insecticidal efficiency of recombinant AcMNPV (WT-31), which serves a theoretical basis for the biological control of L. botrana.

Key words: Lobesia botrana, AcMNPV, CpGV, Bt