Vectors (used by researchers to carry new genes into cells) in which the agent is a baculovirus (i.e., a virus that infects certain types of insects only). These could conceivably be use to make a genetically engineered “insecticide” that is specific to a targeted insect (i.e., wouldn’t harm anything but that insect). For example, a BEV might be used to cause a cotton bollworm adult protein to be expressed when the bollworm is ajuvenile, thus killing the bollworm before it has a chance to damage a cotton crop.