Many folks use isopropyl alcohol as a bug killer. It acts as a contact killer, meaning that it kills on contact. It has no residual effect (stays effective only while wet,) and usually doesn't hurt the plant at all. People like it because it's cheap, available and relatively safe.

Just buy a spray bottle and screw the top spray mechanism onto the alcohol bottle. That way you'll remember what's in the bottle. When a critter is spotted, a few squirts of the spritzer covers the bug with alcohol which usually kills them. If this is ineffective, moisten a cotton ball with alcohol and wipe/squish the critters, solving your infestation.

Keep an eye on the infested plant and watch for further infestations. If this method is ineffective in controlling your problem, you may consider either discarding/destroying the plant or using a "hard" chemical insecticide.