The Warnell School of Forestry at UGA published a story about the impacts of the current drought in northern Georgia on pine trees there. Here is an excerpt from the story describing how drought impacts the trees:
“Drought stresses and weakens trees, making them more likely to be attacked by bark beetles. Under drought, trees do not receive enough water to perform their normal life processes, like converting sunlight to energy. Tree drought responses include leaf wilting, early leaf fall, dying tissue, shutting down roots, and changing chemical process within the tree. Many of these changes occur to conserve water and keep the tree from dying. Even as rainfall conditions return to normal, trees require time to fully recover from their drought response. So there can be a time-lag between increased rainfall and full tree health recovery. Unfortunately, this time-lag and milder winter temperatures gives bark beetles more time to attack pine trees.”
You can read the full story at https://www.warnell.uga.edu/research/news/drought-stressed-georgia-pines-are-dying-engraver-bark-beetle-attacks.