Damage

• While aphids generally do not kill a plant, their feeding can lead to stunted plant growth. Leaves also turn yellow and curl. Aphids also transmit viruses to plants and leave a sticky residue called honeydew when they feed. Caterpillar feeding leads to plant defoliation. In young plants, this can cause stunted growth or death.
  
  

Natural Insecticides

• Spray oils can be used to control aphids. They are created from extracts of the neem tree, cottonseed or refined petroleum products. Bacillius thuringiensis (bt) is a bacterium that specifically targets caterpillars. Home gardeners use a spray form of bt. Agricultural farmers use a liquid form of bt in overhead irrigation systems.
  
  

Chemical Insecticides

• Insecticides that contain permethrin, malathion, pyretrhins or rotenone are available as commercial products in lawn and garden stores. These chemicals can manage aphid and caterpillar populations if applied correctly.