earlier post, but this week I wanted to talk further about the adult beetle behavior and why they only damage young pecan trees.
European chafers are ground dwelling insects so when then fly onto young pecan trees they generally migrate to lower limbs. In the photo at left, you can see that the lowest two limbs of this tree have been attacked by beetles while the upper portion of the tree is untouched. As pecan trees grow larger and lower limbs are pruned off, European chafers will no longer present a problem because these insect can't stand heights.
Spring emergence of adult beetles lasts about 2 weeks. At my location, emergence is trailing off and will be over soon.