As many growers have seen over the past few years, ambrosia beetles can cause major losses in young trees. The ambrosia beetle is a small beetle that bores into the soft tissue of young pecan trees with the intentions of creating a fungal garden inside the tree, which the beetle will use for food. This fungus will cause further damage to the young pecan tree resulting in loss if the tree is not treated.
What to look for.
The picture here shows a young pecan tree that has signs of ambrosia beetles. The small appendages that protrude from the tree trunk or small branches look like worms, but actually that is the digested wood of your young pecan tree that has been removed by the beetle as it bores a hole into the tree. When looking for signs, be sure to remove any herbicide protectors from the tree and look at that portion of the tree as well.
What to do.
If you find you have an infestation of ambrosia beetles, you will need to act quickly and repeatedly until the trees are old enough not to be vulnerable to ambrosia beetles, usually around 6 years old. A pyrethroid will need to be used to spray the trunks of the young trees. We find that we can use our herbicide rig and turn the nozzle so that it sprays a little higher onto the tree, around 4 feet from the ground. Howcver you can also use a simple handheld pump sprayer and accomplish the same thing. If you find that you have ambrosia beetles, it is important to treat all of your young trees in that orchard, and not just the ones you see damage on. We have found it is important to continue to spray our young trees until they reach the age where they are no longer vulnerable.