By: GFC Forest Health’s Brandon Merz and Mark McClure
Southern pine beetles (SPB) gave a lot of Georgia forest landowners headaches last year. The GFC’s spring trapping program is one component of our efforts to mitigate impacts for the most destructive pest of pine trees in the southeastern US.
Southern pine beetles are a native insect species that causes mortality of pine trees when large numbers of the beetles attack. When these attacks increase in size and spread from tree to adjacent tree, they form “spots” of dead trees. During ideal outbreak conditions, these insects can cost landowners losses in both timber and expected financial returns.
Foresters with the GFC will set 50 traps this (spring) season throughout the state. Trap placement will take into consideration counties impacted by the SPB outbreak in 2024 and areas damaged by Hurricane Helene. Traps are set when Eastern redbud trees start to bloom. This usually begins in late February to early March in South Georgia. Traps in the northern part of the state are placed around mid-March. A 12-funnel Lindgren trap is baited with three lures: frontalin, endo-brevicomin, and alpha & beta pinene. The first two lures listed are SPB chemical pheromones, and the last lure mimics a chemical signal released by a host tree. Traps are placed in hardwood stands at least 50 feet away from an overstocked loblolly or shortleaf pine stand. A sample is collected from each trap at a seven-day interval for six weeks. SPB and clerid beetles are counted and uploaded to a Survey 123 app that is used by every state in the Southeast for this project. Clerid beetles are a natural predator of pine bark beetles.
Two prediction models are used: the Texas A&M Model, and the US Forest Service and Dartmouth College and Bates College Model. The first model rates a county’s risk, based on a per-trap per-day catch. The second model adds historic data, to rate counties on the percentage chance of a greater than 50 SPB spots probability. Prediction results from this year’s survey will be available in May.
This project is funded annually by the US Forest Service. The goal is to help landowners and land managers better prepare for and make management decisions about expected SPB populations for the season. The GFC also provides assistance for landowners with management advice and the Southern Pine Beetle Cost Share Program. This program helps offset some of the cost for several silvicultural practices that can prevent or minimize impacts from SPB.
To complement the prediction program, GFC additionally conducts SPB flights from August-September every year to observe and mark new SPB spots from the air. Management foresters meet with landowners to check suspected SPB spots, and hold trainings for landowners and natural resource professionals on identification and management of SPB infestations.
For more information about SPB, visit GaTrees.org, where you can also find contact information for your local GFC forester.