There is great need for a fast-killing, persistent agent to protect high value crops from grasshoppers. Because grasshoppers migrate and modern chemicals do not persist, expensive, repeated treatments are necessary. Nosema locustae (NL), the only available persistent agent, acts too slowly, requiring about 3 weeks to begin killing. In preliminary USDA tests, Nosema AcridoDharus Henrv (NA), another microsporidian, demonstrated speed and virulence, acting in one-third the time of NL, and attacked a much broader tissue range. NA developed to infective spores in 4 days versus 14 for NL, and NA infected important grasshopper species. Questions of economic production, host range, and field persistence remain. This project will define promising methods for in vivo/vitro NA production and should confirm that NA has the remaining primary attributes needed to control grasshoppers - field persistence and sufficient species infectivity. In vivo production approaches will be explored by Bozeman Bio-Tech (BBT), using primarily lepidopteran larvae, because NA production in E. Zea is encouraging. The University of Minnesota will pursue in vitro production in their lepidopteran/orthopteran cell lines. Finally, BBT will define NA field persistence and infectivity range.Applications:This research will identify promising approaches for in vivo/vitro NA production and determine if NA can field-persist and infect enough grasshopper species. If, as expected, our results are positive, NA could reduce chemical sales by S10's to $100's, because it would offer an attractive alternative control strategy to commercial growers, as well as to homeowners. Federal government would benefit from reduced costs of grasshopper control, while enhancing the quality and recreational value of wildlife habitat on public land through reduced chemical use.
