Ever since Louis Pasteur saved the French silk industry by identifying a disease affecting silkworms, scientists have focused their attention on smaller and smaller organisms. Once upon a time, the rhinoceros beetle threatened the coconut plantations of Polynesia until scientists discovered the virus that would control it. In more modern times, the first experimental vaccine for HIV was produced using recombinant baculovirus introduced into insect eggs. Meanwhile, soybeans, corn, and cotton are protected from insects by genes from one insecticidal bacterium, Bacillus thuringiensis--and a...