A schematic representation of recombinant baculovirus generation via homologous recombination. The first step is the generation of a transfer vector-pBacPAK.EGFP-VP39NatP (a), followed by a second step, which is the production of AcEGFP-VP39NatP via homologous recombination (b). VP39NatP, VP39 native promoter; ORF1629NatP, ORF1629 native promoter; EGFP, enhanced greed fluorescent protein; BAC, bacterial artificial chromosome; ChiA, chitinase A; PolP, polyhedrin promoter; del, deletion.