The blue mold fungus produces spores that are the result of both sexual and vegetative reproduction. Resting spores, or oospores, are produced through sexual reproduction and are believed to be involved with long-term survival of the species. Sporangiospores are produced vegetatively as the mold, in essence, makes clones of itself. Sporangiospores can develop by the millions within hours after a tobacco plant is infected, intensifying the need for quick action by farmers who want to save their crops.