The present invention provides pesticidal aerosol compositions and pesticidal methods. The pesticidal aerosol compositions comprise a propellant, 1-methyl-2-nitro-3-[(3-tetrahydrofuryl)methyl]guanidine and N-methyl-2-pyrrolidone, wherein a weight to weight ratio of said 1-methyl-2-nitro-3-[(3-tetrahydrofuryl)methyl]guanidine to said N-methyl-2-pyrrolidone is at a pesticidally synergistic weight to weight ratio. The pesticidal methods comprise applying to a pest or to a habitat of a pest, at least one the pesticidal aerosol compositions.