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Robert Jetton

Associate Professor & Camcore Forest Health Specialist

Jordan Hall 3108

Bio

Education

B.S. Furman University (1997)
M.S. North Carolina State University (2002)
Ph.D. North Carolina State University (2008)

Research Interests

Forest entomology; Invasive forest pests; Community ecology; Arthropod diversity related to habitat type and structure; Gene conservation; Population genetics

Camcore website >>

Area(s) of Expertise

Gene Conservation and Forest entomology/pathology

Publications

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Grants

Date: 09/28/22 - 8/31/25
Amount: $40,000.00
Funding Agencies: US Dept. of Agriculture (USDA) Forest Service

The purpose of this project is to fully develop, evaluate, and deliver an integrated management strategy for conserving and restoring eastern hemlock, an ecologically “keystone” species in eastern North America. The strategy will simultaneously utilize multiple tools (i.e., silvicultural, biological, and chemical tactics) to minimize negative impacts of the invasive hemlock woolly adelgid (HWA). Significant strides have been made in the application of these tactics individually or in paired use, but forest managers have consistently voiced the need for a cohesive strategy that applies multiple tools in the same ecosystem for combined benefit. Our studies will evaluate the interactive effects of silvicultural canopy gaps (that release groups of hemlock trees) and targeted chemical insecticide use (systemic neonicotinoids) on hemlock resilience and on pest and predator abundance The geographic scope of the project includes select sites in the northern and southern Appalachians, but results are expected to be applicable throughout the range of eastern hemlock.

Date: 07/27/22 - 7/31/25
Amount: $65,000.00
Funding Agencies: US Dept. of Agriculture (USDA) Forest Service

The Hemlock Woolly Adelgid is a destructive invasive insect pest of hemlock forests in the Southern Appalachian Mountains. Beneficial bacterial endosymbionts of the adelgid play key roles in the insect's biology, including the digestion of nutrients, defense against natural enemies, and resilience to environmental stress. The PI and his US Forest Service collaborators have recently demonstrated that silvicultural release of infested hemlock trees to increase light exposure and resource availability can make trees more resilient to adelgid infestation. Processes underlying why release is beneficial to the tree are not fully understood, but it is hypothesized that both behavioral responses to sunlight and physiological effects of increased temperatures on the part of the adelgid are involved. The study proposed here will explore the interactions of the adelgid and endosymbionts associated with heat stress across of set of previously established silvicultural release plots to better understand the mechanisms underlying the success of silvicultural release on hemlock health.

Date: 06/06/22 - 5/31/25
Amount: $34,234.00
Funding Agencies: US Dept. of Agriculture (USDA) Forest Service

Previous and ongoing research shows that cutting gaps around individual or small groups of hemlock woolly adelgid (HWA) infested eastern hemlocks to increase the level of sunlight exposure to the crown reduces HWA densities and improves the growth and carbon balance of the tree. How to apply and combine such release strategies with other HWA management tools remains unclear. This project will develop and validate silvicultural thinning tool that will be integrated with existing HWA chemical and biological control strategies to improve the health and long-term sustainability of eastern hemlock in the southern Appalachians.

Date: 09/16/19 - 7/25/24
Amount: $100,000.00
Funding Agencies: US Dept. of Agriculture (USDA) Forest Service

This agreement supports a cooperative project between North Carolina State University and the USDA Forest Service Southern Region for the genetic resource conservation of threatened and endangered tree species in the Southern Region, on the Southern Appalachian forests. Genetic diversity studies are critical in understanding adaptation of imperiled tree species to climate change and forest health impacts. This agreement will allow NCSU, Camcore to identify and add new imperiled tree species to the list for new seed collections. Genetic diversity studies will be done on the species and seeds will be used in restoration efforts on the Southern National Forests.

Date: 05/01/21 - 4/30/24
Amount: $74,449.00
Funding Agencies: US Dept. of Agriculture (USDA) Forest Service

A monitoring program for Carolina hemlock ecosystems will be implemented across the species range. Vulnerability will be assessed using long-term growth, climate, and insect infestation patterns. Growth and mortality rates from the spatially extensive empirical data will be tested against Carolina hemlock status conditions from the Forest Inventory and Analysis program data.

Date: 01/01/22 - 12/31/23
Amount: $150,000.00
Funding Agencies: US Dept. of Agriculture - Agricultural Marketing Service (USDA AMS)

This project will be a collaboration between the Christmas Tree Genetics Program, the Forest Health and Conservation Program, and the Molecular Tree Breeding Lab in the Department of Forestry and Environmental Resources at North Carolina State University. Our goal is to accelerate the genetic improvement of Fraser fir against the tree-killing pathogen Phytophthora root rot and insect pest balsam woolly adelgid. Fraser fir is one of North Carolina’s most important specialty crops generating annual revenues exceeding $100 million. The development of novel genomic tools and technologies will have a positive, transformative impact on the North Carolina Christmas tree industry. Our project builds on resources developed by the NCSU Christmas Tree Genetics Program in collaboration with the NCDA and NC Christmas tree growers over the past 4+ decades. We propose five major objectives in this proposal: (1) genomic resource development of Fraser fir responses to Phytophthora and BWA; (2) identification of Phytophthora and BWA elicitors; (3) evaluation of Fraser fir responses to isolated elicitors; (4) population level analysis of key pest responsive genes in existing NCSU Fraser fir breeding program resources; and (5) synthesis and dissemination of results to NC Christmas tree stakeholders. Subsequent to the funding period, these efforts will benefit the North Carolina Christmas tree community and contribute to the genetic conservation of native Fraser fir populations in the Appalachian Mountains. We expect project deliverables will help address key knowledge gaps of pest resilience in Fraser fir and push conventional conifer breeding strategies and integration with genomic information into a new era.

Date: 03/31/21 - 9/30/23
Amount: $2,800.00
Funding Agencies: Institute of Museum & Library Services

The Center for Plant Conservation received a grant from the Institute for Museum and Library Services (IMLS) for a project entitled, “RNA integrity as a powerful metric of aging in preserved seed collections of wild rare plant species” (MG-245983-OMS-20). To satisfy grant commitments, CPC has the need for a subcontractor to collect a “fresh accession” of rare plant seed from the same wild population previously collected 15 years ago or more and subsequently preserved in orthodox seed storage. The older seed accession currently in orthodox storage will hereafter be known as the “original accession”. Contractor represents that they are able and willing to undertake this work. As the contractor, NC State University will make one “fresh” seed collection from populations of Fraser fir (Abies fraseri) in western North Carolina. Fresh collections will either be made from the same population as the “original accessions”; from ex-situ plants of shared wild provenance; or from plants grown or bulked from seeds of a seed collection held in long term storage for 15 years or more – known as the “original accession.” The specific quantity of seed required for testing may vary depending on the size of seed and inclusion in the different experimental groups. Seed quantities for target species are the estimated quantity of seed needed to achieve 75mg of material plus 100 seeds for a germination trial. The bolded species will need multiple 75mg replicates from the freshly collected accession for inclusion in an advanced aging study.

Date: 11/10/22 - 7/31/23
Amount: $3,109.00
Funding Agencies: Christmas Tree Promotion Board

In collaboration with scientists at North Carolina State University and USDA ARS, scientists at Washington State University will utilize detached branches to determine the potential effectiveness of postharvest fumigation treatments with Bluefume (HCN) in killing elongated hemlock scale (EHS) life stages on infested Fraser fir and determine the effects of HCN fumigation on the postharvest quality of non-infested commonly-grown Christmas tree species,such as balsam fir, Canaan fir, Fraser fir, grand fir, noble fir, Nordmann fir, Turkish fir, Trojan fir, and Douglas-fir). Branches will be fumigated at the USDA ARS Postharvest facility in CA. Treatments will consist of 5 rates of HCN plus a non-fumigated control. Each treatment will be replicated 3 times with 3 branches per replication. Following fumigation, the viability of EHS life stages on infested branches will be assessed. Uninfested branches from the commonly grown species will be transported and displayed in a temperature-controlled room to determine if the fumigation treatments have any adverse effects on postharvest quality and needle retention.

Date: 12/02/21 - 7/31/23
Amount: $2,587.00
Funding Agencies: Christmas Tree Promotion Board

In collaboration with scientists at North Carolina State University and USDA ARS, scientists at Washington State University will utilize detached branches to determine the potential effectiveness of postharvest fumigation treatments with Bluefume (HCN) in killing elongated hemlock scale (EHS) life stages on infested Fraser fir and determine the effects of HCN fumigation on the postharvest quality of non-infested commonly-grown Christmas tree species,such as balsam fir, Canaan fir, Fraser fir, grand fir, noble fir, Nordmann fir, Turkish fir, Trojan fir, and Douglas-fir). Branches will be fumigated at the USDA ARS Postharvest facility in CA. Treatments will consist of 5 rates of HCN plus a non-fumigated control. Each treatment will be replicated 3 times with 3 branches per replication. Following fumigation, the viability of EHS life stages on infested branches will be assessed. Uninfested branches from the commonly grown species will be transported and displayed in a temperature-controlled room to determine if the fumigation treatments have any adverse effects on postharvest quality and needle retention.

Date: 07/12/22 - 6/30/23
Amount: $64,832.00
Funding Agencies: US Dept. of Agriculture - Animal and Plant Health Inspection Service (USDA APHIS)

Establishment of biocontrol agents in Western NC where species acclimated to cooler climates might be more successful, confirming emerald ash borer phenology models for overwintering stages, recovery attempts where parasitoids have been released but emerald ash borer populations have declined.


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