Submitted to: Proceedings of Siconbiol
Publication Type: Abstract Only
Publication Acceptance Date: 6/26/2003
Publication Date: 6/26/2003
Citation: Behle, R.W. 2003. Formulations to improve baculovirus insecticides. Proceedings of the 8th Symposium of the SICONBIOL, p. 43.
Technical Abstract: Development of effective formulations can improve the efficacy of baculovirus insecticides by extending their residual activity after field application. Baculovirus insecticides represent a specific form of augmentative biological control where the biological agent is artificially elevated in the field environment to increase the incidence of disease in the pest population. Baculovirus insecticides have achieved only limited commercialization in the United States because of unfavorable economics and inconsistent efficacy when compared with efficient chemical agents. Formulation research can address some characteristics that limit the efficacy of baculovirus applications, including the rapid loss of insecticidal activity after field application. The association between virus degradation and exposure to sunlight has been recognized for more than 30 years with short wavelength UV-B (300-320 nm) being particularly detrimental to the activity of exposed baculovirus. Researchers can employ different formulation strategies to protect virus from UV inactivation. Formulations may contain ingredients to absorb light thus preventing UV energy from reaching the virus. The energy is often converted to longer wavelength light or heat energy, which does not degrade the virus. Ingredients that absorb UV energy include charcoal, fluorescent brighteners, lignin and color dyes. Other ingredients, such as clays and titanium dioxide, protect the virus from exposure by reflecting the light energy. For an alternative strategy, formulation ingredients can protect the virus by functioning as free radical scavengers and/or antioxidants, essentially short-circuiting the biochemical degradation process. Although numerous ingredients are effective at preventing UV-degradation of viral activity, successful formulations will satisfy the interests of three stake-holder groups with vested interest in the development of biological insecticides: government, industry, and growers. Although the interests of these three stakeholders overlap, the focus of government is on consumer and public safety, the focus of industry is on profit, and the focus of growers is on ease of applications and efficacy. As a result, researchers must consider cost, ease of mixing, compliance with current pesticide application techniques, government registration, production equipment, residual activity, and storage stability while developing improved formulations.