Off the Trail: Oak predators have enemies too

September 14, 2018

When doing moth surveys, I often encounter many other interesting insects by chance.

One of the smallest, but one of the strangest, was the acorn weevil. Many species of weevils exist and tend to specialize for certain host plants. From the name, you can determine this weevil specializes for oak trees by feeding on acorns.

The striking long snout of the acorn weevil, called the rostrum, has teeth at the end of it and is used for boring holes into acorns.

Besides just feeding on the acorns, females will lay their eggs in acorns while they still are on the trees.

The larva will feed on the internal seed flesh until the acorn falls to the ground. Then, the larva crawls out and goes underground for the winter.

These weevils can cause problems for oak regeneration by decimating acorn production up to 90 percent. Lucky for the oaks and us, there are many predators that feed on the weevils, including spiders and specialized weevil wasps. Nature has a plan.

If you have oak trees in your neighborhood, the weevels likely already are around.

iNaturalist observations show a widespread distribution anywhere oak trees exist but favoring the eastern hardwood forest.

I have seen them in my backyard and at Limestone Park locally.

Update hourly