How to Control Borers in Fruit Trees


Borers are the larvae of certain moths and beetles that feed on the wood in trees instead of the leaves or fruits. Borers tunnel into the woody parts of trees, including the trunk, twigs, branches and even the roots. Borer infestations in fruit trees are difficult to control, and insecticidal sprays are only effective during limited times of the borer's life cycle. Several other methods exist, however, to control borer infestations in fruit trees.

Step 1

Look for signs and symptoms of a borer infestation. Study the fruit trees for tunnels that larvae have made in the trunk and limbs. Also look for dying branches.

Step 2

Apply an insecticidal spray to the fruit trees once per month in the summer, following the application directions on the label. Use the insecticide only when the adult borers are active and laying eggs. The timing of insecticide use is crucial, because the insecticides won't work on borer larvae, only on the adults and eggs.

Step 3

Introduce biological controls to eradicate the borers. Trichogramma are small wasps that are parasites to more than 200 moth species, including borers. The wasps lay their eggs inside the borer eggs, and the developing Trichogramma feeds on the borer larvae.

Step 4

Wrap the tree trunks with burlap or three layers of old newspapers. Wrap the fruit trees before the adult borers begin to emerge in the springtime. Make sure that you cover the tree from the ground to the lower branches and leave it on the tree for the first one or two seasons. Wrap any nearby young trees, even if they're not infested, to prevent the adult borers from laying eggs on the bark.

Step 5

Hand-worm the trees by digging the larvae out of their holes in the tree trunk and branches using a wire or knife. Look for the larvae in August and September. The larvae will be easier to find during this time, because the newly hatched larvae will cause sap to flow when they begin to feed. Seal the holes with tree paint immediately after removing the larvae.

Step 6

Keep the fruit trees healthy and injury-free. Fertilize the fruit trees with an appropriate all-purpose granular fertilizer once per month to boost the trees' strength. Water the trees once per week. If the tree is weakened by any other diseases, be sure to treat those as well.

Tips and Warnings

  • Although borers can attack healthy trees, they are more attracted to disease-weakened or injured trees. Be on the lookout for borer infestations if your fruit trees are weak from drought, disease or injuries.

Things You'll Need

  • Insecticide spray
  • Trichogramma
  • Burlap or old newspaper
  • Long wire or knife
  • Tree paint
  • All-purpose granular fertilizer
  • Pheromone traps
  • Whitewash or white latex paint


  • Susan P. Marte, BSc, MSc: Fruit-Tree Borer (Maroga Melanostigma)

Who Can Help

  • University of Missouri Extension: Insect Borers of Fruit Trees
Keywords: control tree borers, fruit tree borers, tree borer larvae

About this Author

Sarah Terry brings 10 years of experience writing novels, business-to-business newsletters, and a plethora of how-to articles. Terry has written articles and publications for a wide range of markets and subject matters, including Medicine & Health, Eli Financial, Dartnell Publications and Eli Journals.