ISCA Technologies proposes to further develop and optimize SPB REPEL, an innovative solution to control the southern pine beetle (SPB), Dendroctonus frontalis Zimmerman, the most destructive pest of southern yellow pine species. SPB is a tremendous problem across southeastern North America, and is expanding its range northwards. SPB causes high levels of tree mortality, especially during population outbreaks like the one that occurred from 1999-2003. During this period, SPB killed >1 million acres of trees, causing large amounts of tree mortality in Alabama, Florida, Georgia, Kentucky, North Carolina, South Carolina, and Tennessee, with estimated economic costs of >$1.5 billion. Such extensive tree mortality can deplete timber supplies, adversely affect levels and distributions of stocking, disrupt management planning and operations, and increase potential for forest fires by adding an abundance of dead, dry timber to available fuels. Current tactics for managing SPB are limited, primarily consisting of strategic tree removals (thinning), prescribed fires, and in some states the use of registered insecticide to protect individual high-value trees. The coordination of SPB individuals to colonize an individual pine tree is almost entirely semiochemically mediated. We propose to explore this aspect of SPB chemical ecology to develop more effective, and environmentally safe management tools to protect pine trees. ISCA researchers along with collaborators from the USDA Forest Service have been studying the chemical ecology of Dendroctonus spp. and have discovered that treatments using various isomers of the anti-aggregation pheromone, verbenone, effectively disrupt the beetles' orientation and host-finding behavior, disabling the semiochemical coordination of mass attacks and providing effective protection of treated trees. ISCA has developed racemic verbenone formulations in recent years that have proven effective at disrupting mass attacks by several species of bark beetles. Still, none of these formulations have proven completely effective in protecting southern pine trees from SPB attack. Building on research indicating that (+)-verbenone, a notoriously difficult-to-synthesize and expensive isomer, can repel SPB more effectively than (-)-verbenone, ISCA seeks to develop an SPB repellent formulation, SPB REPEL, using the (+) isomer of verbenone, an innovation that heretofore has not been commercially viable.