An insect larva aerosol infection method for producing recombinant proteins and baculovirus bio-insecticides is disclosed. A liquid spray of budded form baculoviruses are employed to infect insect larvae in order to reduce the manpower for manual injections and the energy wasted in feeding infection technologies. The invention may be applied to the production of recombinant proteins and baculoviruses as the production platform for bio-insecticides.