Aphids

• Aphids are small, soft-bodied green, yellow or black insects. They feed on plant sap and excrete a sticky honeydew substance. Aphids cause wilting and distort new growth, according to Colorado State University.
  
  

Mealybugs

• Mealybugs resemble tufts of cotton that appear on leaves and stems. They suck plant sap and may also attack roots. A mealybug infestation causes leaf loss and often leads to honeydew excretion.
  
  

Scale

• Scale insects resemble small, shiny brown, yellow or black bumps. They attach themselves to stems and leaves and suck plant sap, creating honeydew. Infestations cause leaf loss and die-back.
  
  

Spider Mites

• Spider mites thrive in dry conditions. They create yellow dots on leaves and can be detected by shaking foliage onto a white piece of paper. Plants become covered in fine webbing when infestations are advanced.
  
  

Thrips

• Thrips are elongated insects less than 1/16 inch in length. They usually are brown, and the adults can fly. Thrip damage is characterized by irregular silvery patterns on leaf surfaces and dark flecks, which is waste. They cause flower bud distortion and scarring.