Submitted to: Association of Formulation Chemists Formulations Forum
Publication Type: Abstract Only
Publication Acceptance Date: March 5, 1999
Publication Date: N/A
Technical Abstract: Bioinsecticides based on insect disease microorganisms have not effectively replaced chemical insecticides as pest control agents. One major disadvantage of bioinsecticides is the loss of activity within hours after exposure to light energy when applied to crops in the field. Identifying formulations to prevent light deactivation of bioinsecticides will provide benefits that will help to increase the use of bioinsecticides. Spray-dried lignin-based formulations of AfMNPV baculovirus have shown improved residual activity when exposed to artificial and natural sunlight exposures. In field tests, unformulated AfMNPV lost most of its insecticidal activity within the first day after application [86% insect mortality at 2 h after application to 30% insect mortality 24 h after application = 35% Original Activity Remaining (OAR)]. Lignin-based formulations designed to resist degradation by sunlight had from 89 to 98% OAR for the same exposure. After 3 days, these improved formulations averaged from 51 to 67% OAR, significantly better than the unformulated treatment one day after application. These results represent dramatic improvements in residual activity of a biopesticide and help to focus future formulation research on specific factors that affect activity.