Granulosis viruses, with emphasis on the GV of the Indian meal moth, Plodia interpunctella.

The granulosis viruses and nuclear polyhedrosis viruses are being considered for use as biological insecticides for control of their insect hosts. Many of these insect species, which include some of the most serious pests of agriculture and forests, have become difficult to control because they have developed resistance to chemical insecticides. Several laboratory and field studies have demonstrated that the baculoviruses (GV and NPV) are promising alternatives to chemicals for the control of economically important insects. These viruses are highly virulent, selective, and stable, and the impact on the environment following their application is minimal. A decision concerning the application of baculoviruses to stored grain and field crops must be based upon a prudent consideration of the benefits to be obtained and the potential risks of their use. Such decisions should be made only after consideration of the physical, chemical, and biological properties of these viruses. In addition, methods must be developed for the unequivocal identification of these viruses, and their effects on nontarget species at the cellular and molecular levels must be investigated. This can best be accomplished if a sufficient body of knowledge regarding the molecular properties of these viruses and their infection process is accumulated by an extensive quantitative approach. Much of this knowledge is lacking because, prior to their consideration for use as insecticides, the baculoviruses appeared to have little medical or economic importance. As a result, interest in studying them was limited. It has become obvious that the molecular properties of these viruses must be investigated if full advantage is to be taken of using them as insect control agents, and if present and future problems concerning their use as insecticides are to be handled properly. Fundamental research on the biochemical and biophysical properties of baculoviruses has concentrated mainly on a variety of nuclear polyhedrosis viruses (Harrap, 1972a,b; Harrap et al., 1977; Summers and Smith, 1975a,b; Arif and Brown, 1975). Much of this progress can be attributed to tissue culture-host cell systems available for the NPVs. The in vitro host system(s) has allowed insect virologists to make phenomenal strides in understanding the cellular and molecular events of virus infection, and, in addition, to enter the era of biochemical sophistication in which animal virology is found at present.(ABSTRACT TRUNCATED AT 400 WORDS)