PPDL Picture of the Week
March 1, 2021
Holes in Trees Are Not Always the Work of Insects
Tim Gibb, Insect Diagnostician, Department of Entomology, Purdue University
Small holes found
in in tree trunks are often blamed on wood boring insects. While insects are truly the culprits in some
cases, many holes are the result of a different animal all together.
the holes on a tree is often a good indicator of what pest is responsible. For example, if the holes are arranged in
neat rows or columns, they can usually be attributed to birds rather than
Sapsuckers, (a type of woodpecker) can be considered pests because they attack living trees. These birds feed largely on sap that they
harvest by drilling a line of shallow holes in the bark of the trees. The
resulting "sap wells" fill with sap and also attract and trap
visiting insects. Both are food sources
for the birds.
injure ornamental and fruit trees, especially if the trees are young. In most cases, however, the damage that they
make is neither permanent nor fatal to the tree.