Effect of recombinant baculovirus expressing C r V 1 protein from C otesia rubecula bracovirus against P ieris rapae in insecticidal toxicity

Baculoviruses can be genetically engineered to express foreign genes; thus, their lethal potency and host range can be improved to produce more virulent bioinsecticides. Polydnavirus ( PDV ) genes have insecticidal bioactivities and could enhance the pathogenicity of the baculoviruses to control insect pests. The C r V 1 gene from C otesia rubecula polydnavirus is responsible for depolymerization of actin cytoskeleton in hemocytes, disabling its spread on foreign object surfaces. In this study, we tested the efficacy of the recombinant baculovirus ( A c MNPV ‐ C r V 1) under p10 promoter against second instar P . rapae larvae. The expression of the C r V 1 gene in P . rapae larvae was verified with reverse transcription–polymerase chain reaction ( RT‐PCR ). A c MNPV ‐ C r V 1 showed a significantly lower median lethal concentration ( LC 50 ) and shorter median lethal time ( LT 50 ) as compared with the A c MNPV wild‐type virus. These results suggested that the expression of C r V 1 protein could successfully improve the insecticidal toxicity of baculovirus.