Procedures are described which use solvents to increase the topical insecticidal activity of toxic insect peptides. These procedures comprise drying the peptides, if needed, followed by the addition of either: 1) a polar organic solvent, with or without water, to a dried peptide, or 2) the addition of polar aprotic solvent or other adjuvant to the dried peptide, followed by the addition of either: 1) a polar organic solvent, with or without water, (where a polar aprotic solvent is added first) or 2) a polar aprotic solvent or other adjuvant to the peptide polar organic solvent (where the polar organic solvent is added first), to the peptide formulation.