In 2017, Dean Greene assembled the Dean's Advisory Board to replace our former External Advisory Committee. This group will work alongside our two active alumni committees with a specific focus on assisting the dean with strategic planning and networking across disciplines to help support private giving to the Warnell School. We thank all of these accomplished and talented people for their longstanding support of our program and their willingness to serve the school in this vitally important role.

Alumni & Giving at Warnell

Activities in the Aquatic Toxicology lab primarily involve determination of the effects of environmental pollutants on aquatic organisms such as fish and freshwater mussels. We are also interested in investigating the early life history of freshwater mussels, particularly the obligate parasitic larval stage which must attach to a suitable host fish for transformation to the juvenile stage. For culture of aquatic organisms the wet lab is equipped with temperature controlled systems including a stand-alone fish keeping system with 30 aquaria, a Living Stream, and numerous aquaria for contaminant exposures. The lab has a multifunction plate reader for performing ELISAs and other colorimetric assays, extraction and homogenization equipment for biological and environmental samples, a stereo microscope with image analysis software, incubators, centrifuges, balances, a -80C freezer, an ultrapure water system and general lab equipment for collecting processing samples.

Other research

Avian Vacuolar Myelinopathy (AVM) Research by Dr. Susan Wilde

• Watch Dr. Wilde present her work to the Raptor Research Foundation

Our lab is interested in understanding how biotic and abiotic factors influence the physiology of trees and how the physiological mechanisms of trees regulate ecosystem processes. Our main research themes are focused on water, carbon, and nitrogen cycling in forest ecosystems. Within these research themes, we explore both basic and applied questions. Indeed, much of our research is related to applied bioenergy production and sustainability questions, but we are keen to leverage the simplified ecological framework afforded by these systems to probe basic ecological and physiological processes. We are particularly interested in belowground processes and interactions between above- and belowground processes.

Members of the Alumni Steering Committee work together to support events, programs, and philanthropic initiatives that help the school accomplish its mission. The 13 members serve a 3 year term and assist with planning regional events, advising engagement strategies, and nominating Warnell alumni for UGA’s Bulldog 100, 40 under 40, and other awards. Members should be a current Warnell donor. By encouraging Warnell alumni and friends to remain involved and support the school, this committee is actively involved in bringing Warnell together in a spirit of fellowship.

New Member Nominations

The deadline for new member nominations is October 1, 2023. Eligible alumni should be willing to support the school's fundraising initiatives as a current donor.

NOMINATION FORM

OVERVIEW OF ASC MEMBERSHIP

Welcome! Our lab is interested in understanding the interactions among trees, fungal pathogens and insect herbivores, with particular attention to chemical ecological aspects.

Part of our work focuses on symbioses between bark beetles and Ophiostomatoid fungi, and on tree defense mechanisms, driven by the curiosity to understand the role of associated fungi in bark beetle establishment in the host. We are also interested in how abiotic disturbances influence the pathogen/host interaction. Finally, we use cutting-edge molecular techniques to detect invasive species directly in the field.

Projects

Leptographium complex

We study Leptographium and Grosmannia species associated with root-feeding beetles in the southeastern forests. Our research objectives are to elucidate the fungal species carried by native and exotic root-feeding beetles in healthy and unhealthy pine stands, to determine the pathogenicity of the different Leptographium species, and to analyze the host response to colonization by the fungi.

This project is a collaboration with Dr. Gandhi (Forest Entomologist at Warnell, UGA) and Dr. Klepzig (Jones Ecological Research Center).

Laurel wilt disease diagnosis

We are developing and validating a LAMP (loop mediated isothermal amplification) based assay for the rapid, in-field, early detection and identification of the causal agent of laurel wilt disease (LWD). Laurel wilt is a devastating disease which is decimating redbay and threatening other lauraceous species, including sassafras throughout the eastern USA, California bay on West Coast and commercial avocado. The disease is caused by Raffaelea lauricola, an invasive fungal pathogen vectored by the redbay ambrosia beetle. Early detection and rapid sanitation of infected plants are crucial steps to slow disease spread, and critical components of an integrated pest management program.

LAMP is an innovative molecular technology that meets all the major technical and economic requirements for successful in-field implementation by non-technical users, and has been already optimized for the detection of tree pathogens using portable devices (e.g., sudden oak death and ash dieback). In addition, despite being performed in few simple steps, LAMP is highly sensitive, and potentially able to detect the pathogen even in asymptomatic tissues, or directly on the insect vectors. Trained forest health monitoring personnel, equipped with portable devices, will be able to confirm the diagnosis of LWD in both symptomatic and asymptomatic samples, or identify a potential insect vector, in as short as 30 minutes, without having to rely on traditional, costly, time-consuming laboratory procedures.

This project is a collaboration with Dr. Fraedrich (USDA Forest Service), and is funded by the USDA Forest Service Special Technology Development Program.

Little leaf disease

This study is part of a bigger project aimed at identifying the drivers of the recent Ips avulsus beetle outbreak on the Oconee Ranger District. The pathology component of the project is looking at the incidence of Phytophthora cinnamomi, a root pathogen which causes littleleaf disease on pine trees. The presence/absence of P. cinnamomi  is assessed via isolation on selective media from soil and root samples, followed by molecular confirmation of the pathogen identity. Phytophthora species other than P. cinnamomi are also monitored.

This project is a collaboration with Dr. Gandhi, Dr. Morris (Forest Entomologist at Warnell, UGA), and Ms. Beard (USDA Forest Service), and is funded by the USDA FS Chattahoochee-Oconee National Forest.

Sugarberry decline and mortality

Sugarberry or southern hackberry (Celtis laevigata) is a medium size tree that is common in many forest types throughout the southeastern USA. A decline and mortality of the species has been recently observed in both forest and urban areas of South Carolina and Georgia, but causes of the disease are not understood. Trees affected by the disease exhibit an array of symptoms including leaf chlorosis, development of smaller than normal foliage, early leaf drop/thinning crowns, and a progressive crown dieback which occurs over one to several years. The stems and roots of affected trees develop a brownish discoloration in the phloem early in the disease cycle, and the discoloration appears to spread throughout the phloem as trees succumb to the disease. A number of insect pests and potential pathogens have been associated with the decline, however, at this time most of these appear to be secondary opportunistic organisms rather than primary causal agents.

Phytoplasmas, viruses and bacteria, including fastidious bacteria, have all been associated with various types of decline and are notoriously difficult to diagnose and not readily identified in symptomatic trees without using molecular approaches. The objective of this project study is to determine if and what types of bacteria and phytoplasmas are associated with the phloem of declining sugarberries by using a metabarcoding approach, with the overarching goal of moving forward with the understanding of the causal agent(s) of the sugarberry decline.

This project is a collaboration with Drs. Cram, Fraedrich, Olatinwo and Ulyshen (USDA Forest Service), and is funded by the USDA FS Special Technology Development Program and the USDA FS Southern Research Station.

Publications

Book chapters (peer reviewed)

Hofstetter R.W., Klepzig K.D., Villari, C., 2021. Effects of rising temperatures on ectosymbiotic communities associated with bark and ambrosia beetles. In Bark Beetle Management, Ecology, and Climate Change (pp. 303-341). Academic Press

Journal articles (peer reviewed)

Download the full list.

Hadziabdic D., Bonello P., Hamelin R., Juzwik J., Moltzan B., Rizzo D., Stewart J., Villari C., 2021. The future of forest pathology in North America. Front. Frontiers in Forests and Global Change 4:737445. doi.org/10.3389/ffgc.2021.737445

Aglietti C., Meinecke C.D., Ghelardini L., Barnes I., van der Nest A., Villari C., 2021. Rapid detection of pine pathogens Lecanosticta acicola, Dothistroma pini and septosporum on needles by probe-based LAMP assays. Forests 12:479. doi.org/10.3390/f12040479

Hamilton J.L., Fraedrich S.W., Nairn C.J., Mayfield A.E., Villari C., 2021. A field-portable diagnostic approach confirms laurel wilt disease diagnosis in minutes instead of days. Arboriculture & Urban Forestry 47:98-109. doi.org/10.48044/jauf.2021.010

McNichol B.H., Sullivan B., Munro, H., Montes C.R., Nowak J.T., Villari C., Gandhi K.J.T. 2021. Density-dependent variability in an eruptive bark beetle and its value in predicting outbreaks. Ecosphere 12:e03336. doi.org/10.1002/ecs2.3336

Pandit K., Smith J., Quesada T., Villari C., Johnson D., 2020. Association of recent incidence of foliar disease in pine species in the southeastern United States with tree and climate variables. Forests 11:1155. doi:10.3390/f11111155

Hamilton J.L., Workman J.N., Nairn C.J., Fraedrich S.W., Villari C., 2020. Rapid detection of Raffaelea lauricola directly from host plant and beetle vector tissues using loop-mediated isothermal amplification. Plant Disease doi:10.1094/PDIS-02-20-0422-RE.

Hulcr J., Barnes I., De Beer Z.W., Duong T.A., Gazis R., Johnson A.J., Jusino M.A., Kasson M.T., Li, Y., Lynch S., Mayers C., Musvuugwa T., Roets F., Seltmamm K.C., Six D., Vanderpool D., Villari C. Bark beetle mycobiome: collaboratively defined research priorities on a widespread insect-fungus symbiosis. Symbiosis 81:101-113. doi:10.1007/s13199-020-00686-9

Munro H.L., Gandhi K.J.K., Barnes B.F., Montes C.R., Nowak J.T., Shepherd W.P., Villari C., Sullivan B.T, 2020. Electrophysiological and behavioral responses Dendroctonus frontalis and terebrans (Coleoptera: Curculionidae) to resin odors of host pines (Pinus spp.). Chemoecology doi:10.1007/s00049-020-00311-7.

Bonello P., Campbell F.T., Cipollini D., Conrad A.O., Farinas C., Gandhi K.J.K., Hain F.P., Parry D., Showalter D.N., Villari C., Wallin K.F., Invasive Tree Pests Devastate Ecosystems—A Proposed New Response Framework. Frontiers in Forests and Global Change 3:2. doi:https://doi.org/10.3389/ffgc.2020.00002

Conrad A., Villari C., Sherwood P., Bonello P., 2020. Phenotyping Austrian pine for resistance using Fourier-transform infrared spectroscopy. Arboriculture & Urban Forestry 46:276-286. 

Munro, H. L., Sullivan, B. T., Villari, C., Gandhi, K. J. K. 2019. A review of the ecology and management of black turpentine beetle (Coleoptera: Curculionidae). Environmental Entomology 48:765-783 doi:10.1093/ee/nvz050

McNichol, B. H., Montes, C. R., Barnes, B. F., Nowak, J. T., Villari, C., Gandhi, K. J. K. 2019. Interactions between southern Ips bark beetle outbreaks, prescribed fire, and loblolly pine (Pinus taeda L.) mortality. Forest Ecology and Management 446:164-174 doi:10.1016/j.foreco.2019.05.036

Lopez-Goldar, X., Villari, C., Bonello, P., Borg-Karlson, A. K., Grivet, D., Sampedro, L., Zas, R. 2019. Genetic variation in the constitutive defensive metabolome and its inducibility are geographically structured and largely determined by demographic processes in maritime pine. Journal of Ecology 107: 2464-2477 doi:10.1111/1365-2745.13159

Mayfiled A.E., Villari. C., Hamilton J.L., Slye J., Langston W., Oten K., Fraedrich S. 2019. First Report of Laurel Wilt Disease caused by Raffaelea lauricola on Sassafras in North Carolina. Plant Disease 103:155 doi:10.1094/PDIS-05-18-0871-PDN

Rigsby C.M., Villari C., Peterson D.L., Herms D.A., Bonello P., Cipollini D. 2019. Girdling increases survival and growth of emerald ash borer larvae on Manchurian ash. Agricultural and Forest Entomology 21:130-135. doi: doi.org/10.1111/afe.12292

Lopez-Goldar X., Villari C., Bonello P., Borg-Karlson A.K., Grivet D., Zas R., Sampedro L. 2018. Inducibility of plant secondary metabolites in the stem predicts genetic variation in resistance against a key insect herbivore in maritime pine. Frontiers in Plant Science doi: doi.org/10.3389/fpls.2018.01651

Villari C., Dowkiw A., Enderle R., Ghasemkhani M., Kirisits T., Kjaer E., Marčiulynienė D., McKinney L., Metzler B., Muñoz F., Rostgaard Nielsen L., Pliūra A., Stener L-G, Suchockas V., Rodriguez-Saona L., Bonello P., Cleary M. 2018. Advanced spectroscopy-based phenotyping offers a potential solution to the ash dieback epidemic. Scientific Reports 8:17448 doi: doi.org/10.1038/s41598-018-35770-0

Mason C.J., Keefover-Ring K., Villari C., Klutsch J.G., Cook S., Bonello P., Erbilgin N., Raffa K.F., Townsend P.A. 2018. Anatomical defenses against bark beetles relate to degree of historical exposure between species and are allocated independently of chemical defenses within trees. Plant, Cell and Environment doi: doi:10.1111/pce.13449

Showalter D.N., Villari C., Herms D.A., Bonello P., 2018. Drought stress increased survival and development of emerald ash borer larvae on coevolved Manchurian ash and implicates phloem-based traits in resistance. Agricultural and Forest Entomology 20:170-179. doi:10.1111/afe.12240

Extension Publications

Ulyshen, M., Fraedrich, S., Cram, M., Horn, S., Villari, C., Niyas, A., Poole, E. 2019. Pest Alert – Sugarberry dieback and mortality. USDA – Forest Service – R8–PR–02–19

Gandhi, K., Klepzig, K., Barnes, B., Gochnour, B., Mccarty, E., Sheehan, T., Villari C., Vogt, J. T. 2019. Bark and woodboring beetles in wind-damaged pine stands in the southern United States. Warnell School of Forestry and Natural Resources – WSFNR 19-38.

Mccarty, E., Cassidy, V., Gandhi, K., & Villari, C. 2019. Nantucket pine tip moth: An insect pest of young pine stands. Warnell School of Forestry and Natural Resources – WSFNR 19-34.