Insect Virology

Virology, that useful but ugly word of doubtful parentage, comprises the study of viruses, irrespective of the host organism from which the virus comes, just as bacteriology comprises the study of bacteria. It is necessary to emphasize this point because for many years there was a tendency, especially among workers studying the viruses affecting the higher animals, to regard the virus diseases of bacteria, plants, insects, and higher animals as caused by four separate and distinct types of disease agents. The time has now long gone by when it could be stated that "plant viruses are of an entirely different nature from that of the animal viruses." A virus is a virus regardless of its derivation and, as we shall see later in this book, the multiplication of a plant virus inside an animal, the insect vector, emphasizes the artificiality of host barriers.