When their exoskeleton deteriorates, the insects become dehydrated and die. Make sure you have these materials on hand when making insecticidal soap. Spray bottle Distilled water Castile soap ...

A 32-ounce bottle of concentrated solution costs between $15 and $30, but it will make five or six times as much spray as a ready-to-use product. The active ingredient in insecticidal soap is the ...