Viral insecticide effect

Vasil eva, V.L. et al. (1984). Effect of baculoviruses on health of workers involved in production of viral insecticides, Vrachebnoe delo (5), 116-119, May. Translanted in JPRS Report, Science and Technology, USSR Life Sciences. 

Methodologies most often used for formulation and application of viral insecticides are those developed for conventional chemical insecticides. Viral insecticides are most effectively formulated as wettable powders by lyophilization or spray dry methods. These formulations are best standardized using both counts of occluded virus particle concentration and bioassay activity. Viral insecticides are typically applied as sprays against larval pests of Lepidoptera and Hymenoptera (sawfly) using both aerial and ground equipment. Spray parameters for viral insecticides are not well understood and available equipment is not suitable for their most efficaceous use. Much of the research on virus application has been on development of adjuvants for tank mixtures to overcome problems with plant coverage and sunlight inactivation. 

Viral insecticides kill slowly and result in lower mortalities than chemical insecticides in most instances. This often dictates that virus application be directed against pest populations of lower density than would be necessary for chemical insecticides. The lower levels of control obtained and the short residual period of viral insecticides may also require that virus treatments be timed closer together and applied more often than for chemical insecticides. Because viral insecticides are less effective than chemicals in producing quick results, they are less likely to control high population densities of the target population. Because producers are accustomed to evaluating the effectiveness of the fast-acting chemical insecticides, they find it difficult to delay their evaluation of virus application for the several days or even weeks often required for treated larvae to die (31). If not properly trained, users may switch to chemical insecticides prematurely and never realize that the virus would have been efficaceous. 

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