Types

• Garlic or red pepper solutions have been touted as insecticides, but studies have not proved their effectiveness. Instead, homemade non-toxic insecticides that work are soap-based mixtures. An effective 1 to 2 percent solution of soap calls for 5 tablespoons of mild dish detergent per 1 gallon of water.
  
  

Function

• Homemade insecticidal soap needs to come into contact with target insects. The spray must cover the insect's body at application; when the spray has dried and the insect moves across the residue, the insect will not be harmed. Use the insecticide repeatedly and plentifully to ensure complete coverage of the insects to be eliminated.
  
  

Benefits

• Homemade insecticidal soaps have a 40 to 50 percent effectiveness rate in killing soft-bodied insects, including aphids, whiteflies and spider mites. They do not kill hard-bodied insects like bees and beetles. This is a benefit; beneficial insects tend to remain unharmed.
  
  

Warning

• Even dish soap with low toxicity to humans needs to be used carefully. Eye irritation, danger to other mammals and damage to plants are possible if the soap solution is too strong.