Codling Moth

• Codling moths are small gray moths that blend in well with tree bark; they attack apple and pear trees. Their larvae ranges from white to pink and they're one of the only caterpillars often found inside pears and apples. This moth's larvae tunnel into fruit and if left unattended can affect 20 percent to 90 percent of the fruit on a tree. To keep codling moths off fruit you can bag the fruit while it is still on the tree. If infestation occurs the fruit may need to be treated with an insecticide.
  
  

Peach Twig Borer

• Peach twig borers are dirty white or light brown, which allows them to camouflage themselves in fruit and on trees. Their eggs are laid on the underside of leaves and they can be easy to miss without a vigilant eye. These insects bore into the shoots of growing twigs of ripening fruit and nuts. To rid your plant of this insect it may be necessary to use a chemical or organic pesticide, which works best when applied as soon as trees are sprouting.
  
  

Aphids

• Aphids are commonly referred to as "plant lice" and are small insects that suck sap from trees. Aphids are small insects that can be brown, green, pink, black or nearly colorless. While aphids only eat the sap of trees, they are one of the most destructive plant pests because they reproduce so quickly that they are hard to control once they infest a tree. Aphids suck the sap from trees but also leave saliva behind that can be detrimental to the life of the plant.
  
  

Caterpillars

• Caterpillars eat leaves of most any plant and can cause plants to decay. Caterpillars range in colors from a solid to a patterned design; no matter the color they are made to blend in with the plant that they are eating. Caterpillars are hard to control as they have evolved over time and have become immune to many commonly used pesticides on the market; once caterpillars infest your garden they are hard to get rid of.