The basic premise behind this may be the Nuclear Polyhedris Virus, NPV, but freezing the whizzed bugs right after whizzing them would not allow this to develop. The initial research into NPV showed that the whizzed bugs needed to steep for at least 24 hours for the Virus to grow. So the way to utilize this is to gather several of the target insects (say the Japanese Beetles), whiz them in a bit of water in your blender (you probably should use a blender that will not be used for fixing food for the family after this), let that mixture steep for 24 hours, and then dilute it and strain it, and spray it around the garden. The theory is that each insect species carrys the virus that will kill them but it needs encouragement to grow.