Types

• Adult peach tree borers and lesser peach tree borers are wasplike, day-flying moths with clear wings, dark-blue bodies and yellow or orange banding. Peach tree borers produce creamy-white larvae with brown heads, while lesser peach tree borers produce slightly smaller and pinkish-colored larvae. Peach twig borer adults are small grey moths; their immature larvae are white, while older larvae are deep brown. Pacific flatheaded borers are 0.5- to 0.75-inch, dark-bronze beetles. Their larvae have flattened white bodies and brownish-yellow heads.
  
  

Effects

• Peach tree and lesser peach tree borer larvae burrow below the bark, leaving a gummy residue mixed with bug excrement, called frass, as well as sawdust and wood bits near the base of the tree. Peach twig borers enter twigs and branches and attack new shoots from the inside, causing dieback. Pacific flatheaded borers feed on the soft material between the wood and the bark, cutting off the nutrient and water supply from the roots.
  
  

Prevention/Solution

• Keeping trees in high vigor through pruning and watering will enable them to resist attacks. Endosulfan insecticidal sprays are used to protect trees from borer infestations. Peach tree and lesser peach tree borers can also be killed by hand by inserting a flexible wire inside the burrow to impale the insect. Peach twig borers are prevented by spraying dormant peach trees to kill hibernating larvae. Pacific flatheaded borers, which attack weak or damaged trees, are prevented by painting the trunks with white latex paint or white wash to prevent sunburn injury.