Question: Why do my pecans not fall at the proper time, but stay in the trees into the winter?
Answer: Hickory shuckworms tunnel around in the husks starting in late summer. They cut off the supply lines to the developing kernels, stopping their growth in the process. The nuts stop developing and hang in the trees well into the winter. When they do fall you will find them to be hollow. Use a general-purpose fruit and pecan insecticide in early August. Repeat the spray in late August.