States Department of Agriculture -
||Southern Research Station
200 Weaver Boulevard
P.O. Box 2680
Asheville, NC 28802
SOUTHERN PINE BEETLE
New Research Funded by the Southern Research Station (SRS)
The southern pine beetle (SPB) is the most serious pest of coniferous forests in the southern United States. Outbreaks of southern pine beetle cause severe economic losses and unparalleled ecological disturbance. Recent outbreaks have been among the worst recorded, and threats continue to worsen. The SRS Bark Beetle and Invasive Insect unit (SRS-4501) based in Pineville, LA has southwide responsibility for research on southern pine beetle and has contributed much to the fundamental understanding of the insect. Increased funding in recent years has allowed the unit to expand existing research and focus new efforts on the biology (including associated organisms, plant-insect interactions and natural enemies), population dynamics, and control of southern pine beetle. This year, SRS-4501 sent out a request for proposals (RFP) for research projects to improve prevention, develop ways to protect individual trees and areas of highly valued trees and to restore SPB-damaged land, and refine the monitoring strategies that allow managers to reliably predict SPB population trends.
Approximately $800,000 was available to fund cooperative research with SRS-4501 and competitive proposals from external partners. A total of 32 proposals were received. The proposals were peer reviewed and evaluated by a panel of forest science professionals for relevance, quality of science, and probability of timely success. The competitive grants program was able to fund seven of the 32 proposals. In addition, the unit developed six cooperative research agreements with partners to address existing unit research goals.
Competitive grants projects funded:
- Genetic screening for resin traits linked to SPB resistance. John Davis (University of Florida), Dana Nelson (SRS-4153) and Brian Strom (SRS-4501) will examine the genetic basis for resin flow in pine (a key factor in resistance of trees to southern pine beetle). They will measure resin flow phenotypes in seedlings and adult trees, and identify 100 candidate genes by probing 1000 element gene arrays, using this data to associate resin phenotypes with mapping data.
- Pheromone biosynthesis in southern pine beetle. Steve Seybold (PSW-4502), and Kier Klepzig and Brian Sullivan (SRS-4501) will examine key aspects of pheromone production in SPB. Pheromones are essential to the ability of southern pine beetle to successfully attack and kill trees. They will determine the origin of trans -verbenol, verbenone, and endo -brevicomin in southern pine beetle.
- Inferring the magnitude of SPB migration using genetic markers and diffusion models. John Reeve (Southern Illinois University) and Brian Strom (SRS-4501) will use molecular tools to measure the movement of southern pine beetles between populations, a key factor to understanding how SPB populations go from low (endemic) to outbreak levels. They will develop microsatellite markers in southern pine beetle, and synthesize information on SPB short range movement into a diffusion equation framework.
- Guidelines for regenerating small patches of forest killed by southern pine beetle. Jeff Goelz (SRS-longleaf) will synthesize applicable research in areas of artificial and natural regeneration, physiology, ecology and silviculture, and light levels within forest gaps into a guide for land managers wanting to restore small areas affected by southern pine beetle,
- Developing and validating a methodology for monitoring and tracking changes in SPB hazard at the landscape level. Shailu Verma (Forest One, Inc.), and Ronald Billings (Texas Forest Service) will use satellite imagery to rate the risk of attacks on forests by southern pine beetle. They will develop and validate a methodology for monitoring and tracking changes in SPB hazard at the landscape level in Texas, and will provide an economic analysis of the feasibility of conducting such ratings across the southern States.
- Revegetation and forest succession of SPB-killed stands in the Southern Appalachian/Cumberland Plateau region. Lynne Rieske-Kinney (University of Kentucky) will examine the impacts on forest succession of management practices after SPB outbreaks by quantifying revegetation and forest sucession of SPB-killed shortleaf pine stands in the Southern Appalachian/Cumberland Plateau region.
- SPB population dynamics in stands of loblolly pine: a computer simulation study that allows variable host resistance. John Bishir (North Carolina State University) and Jim Roberds (SRS-4153) will use mathematical modeling to determine the extent to which changes in resin flow affect SPB spot development. They will identify circumstances leading to spot development, and determine the extent to which lowest winter temperature can predict SPB infestation levels.
Cooperative agreements funded:
- Molecular dissection of two mycangial glands in southern pine beetle. Cetin Yuceer and T. Evan Nebeker (Mississippi State University), and Kier Klepzig (SRS-4501) will determine how southern pine beetle carry and sustain the fungi they depend on for nutrition. They will molecularly dissect the two SPB mycangial glands, identifying the enzymes associated with these glands and their role in the SPB life cycle.
- Prediction of SPB populations: interactions of tree species, spatial distribution, resin flow rate, and sapflow rate. James Costa (Western Carolina University), Brian Kloeppel (SRS-4351, University of Georgia), and Kier Klepzig and Brian Strom (SRS-4501) will examine resin flow (a key part of tree defense against southern pine beetle) in three pine species in the Appalachians. They will establish study plots of shortleaf, pitch, and white pine, and compare resin flow in these species across moisture gradients.
- Determination of the gut microflora of southern pine beetle. Ken Raffa (University of Wisconsin-Madison) and Kier Klepzig (SRS-4501) will determine the role of bacteria in the life cycle of southern pine beetle. They will use molecular techniques to determine the microbial species composition within the guts of the insect.
- Resin flow and growth traits in clonal loblolly pine. Fred P. Hain (North Carolina State University) and Brian Strom (SRS-4501) will examine the relationship between growth and resin yield in loblolly pine. They will develop estimates of variation in juvenile resin yield and growth in a clonal population of loblolly pine.
- Evaluation of inhibitory volatile compounds and histerid predators for SPB control. Richard Goyer and Will Shepherd (Louisiana State University) and Brian Sullivan (SRS-4501) will examine the role of volatile compounds in preventing SPB attack and attracting SPB predators. They will use electroantennal detection techniques to identify antennally-active volatile compounds arising from hosts found to be unsuitable for southern pine beetle.
- Identification of a pheromone for an undescribed Dendroctonus sp. in Central America. Ronald Billings (Texas Forest Service) and Jorge Macias-Samano (El Collegio de la Frontera Sur) will examine the taxonomy, biology and chemical ecology of a potential new species of Dendroctonus (closely related to southern pine beetle and of potential invasive insect concern).