The following guidance summarizes the data presently required by the Agency to show the safety of nuclear polyhedrosis and granulosis virus insecticides. When testing the safety of insect viruses, primary emphasis must be given to their pathogenicity and not to their toxicity. Pathogenicity is the capability of the microorganism to infect or reproduce, or to cause overt or covert changes, in animals or animal tissue other than target insects. Toxicity means that microorganisms, and/or their by-products, harm the test animal without actual multiplication such as in certain adverse immunological reactions.