Entomology: Personnel

Entomology Faculty

Tracie M. Jenkins Assistant Professor of Applied Insect Genetics Concentration: The population genetics of urban structural and horticultural insect pests Griffin Campus Ph.D., University of Georgia, 1993 Appointment: 50% Research: 50% Teaching Contact Information Address: Department of Entomology UGA Griffin Campus 1109 Experiment Street Griffin, GA 30223-1797 Phone: (770) 412-4093 Email: jenkinst@uga.edu

Courses Taught

GENE 3000, Evolution, 4 credits, Spring Semester, (syllabus)
GENE 3200, Genetics, 4 credits, Fall Semester, (syllabus)
HORT 4800, Biotechnology, 3 credits, Fall Semester, (syllabus)
PGEN 3580, Plant Genetics, 3 credits
AESC 4950, Undergraduate Research in Agricultural and Environmental Science,
       2–3 credits, Fall and/or Spring, TBA with each student
AESC 4960, Special Problems in Agricultural and Environmental Science,
       2–3 credits, Fall and/or Spring, TBA with each student

Lab Personnel

Tyler Eaton, Technician

Research

Overview: The genetics of urban and horticultural insect pests.
The overall purpose of my research is to apply DNA marker technology to the study of geographic population structure, gene flow, phylogeography, speciation, molecular systematics, and phylogenetics and insect-plant host interactions of urban and horticultural insect pests. My lab collaborates on studies from urban structural pests such as subterranean termites (Rhinotermitidae) and ants (Hymenoptera: Formicidae) to urban horticultural pests which includes flea beetles (Coleoptera: Chrysomelidae), lace bugs, Stephanitis pyrioides (Heteroptera: Tingidae), and azalea caterpillars (Lepidoptera: Notodontidae).

            My work is driven by the belief that the application of DNA molecular technology in the context of evolutionary theory will provide the template and necessary data to develop effective insect pest management strategies and provide the basis for understanding insect pest efficacy test results.

Black Carpenter Ant, Camponotus pennsylvanicus (Hymenoptera: Formicidae)

Camponotus species are serious pests that cause billions of dollars in wood damage annually in the United States. They, unlike termites, do not eat wood but excavate and nest in it. The black carpenter ant, Camponotus pennsylvanicus (DeGeer), is a prevalent structural pest of the eastern and central United States; and, may even be the most common carpenter ant pest east of the Mississippi River. These ants will establish primary or satellite colonies in dry, sound wood throughout a structure such as in support timbers, roofs, shingles, garages, window frames and sills. Thus, in the southeastern United States the growing urbanization, which includes building near forested areas, and ecological changes due to warming trends are likely exacerbating the problem of C. pennsylvanicus infestations. In collaboration with Dr. Dan Suiter, UGA Entomology, and using an integrative protocol, which includes field work, behavioral studies and DNA marker technology, my lab has begun a longitudinal study the purpose of which is to understand the intra- and intercolony structure of 20 C. pennsylvanicus colonies. We expect to illuminate intra- and intercolony spatial and temporal gene flow that will help interpret efficacy test results.

Flea beetles (Coleoptera: Chrysomelidae)

Flea beetles are serious pests of horticultural and agricultural plants. Our overall purpose is to understand the insect host-plant interactions of flea beetles that attack plants in the Onagraceae and Lythraceae families in order to develop effective control strategies. My lab in collaboration with Dr. Kris Braman, UGA Entomology, is conducting a longitudinal study, the objectives of which are to determine the molecular taxonomy, gene flow, and phylogeny and insect-host plant co-evolution of beetles in the genus Altica. Our initial results show host plant specificity, a relationship between morphology and DNA character states, unrestricted gene flow across states and ecoregions, and possible positive assortative mating.

Termites (Isoptera: Rhinotermitidae)

Molecular Taxonomy
Accurate species identification underlies all termite field studies and population genetic research. With more than 170 species of termites in Peninsular Malaysia, it has been challenging to elucidate proper taxonomic records among the species, particularly within the family Termitidae. This lack of taxonomic clarity hampers many studies on termites in this area of the world. My lab in collaboration with Dr. Chow-Yang Lee, School of biological Sciences, Universiti Sains Malaysia, Penang, Malaysia, is presently studying the taxonomy of species within the family Termitidae. Individual termites are first identified to species and or genus by morphometric characters. Taxonomic fidelity from morphometric characters is then determined by distance matrix and character-state phylogenetic analyses of sequence data.

Termite mounds in Northern Australia

Gene flow, natural history
Coptotermes gestroi, the Asian subterranean termite (AST), C. formosanus, the Formosan subterranean termite (FST), and R. flavipes, the eastern subterranean termite (EST), are economically important exotic and indigenous structural and agricultural pests that have become established in many areas of the world including the United States. Current collaborative research with Brian Forschler, UGA Entomology, Dan Suiter, UGA Entomology, and Susan Jones, OSU Entomology, concerns using DNA data to determine the phylogenetic relationships of AST and FST collected in indigenous locations within Asia and Southeast Asia as well as from areas of introduction in South America and the United States and its territories. The overall purpose of this research is to use optimality criteria encompassing phenetic and cladistic assumptions coupled with phylogeographic theory and historical data to identify where exotic termites originate and their mechanism of dispersal. This is a crucial step for developing possible interdiction policies to curtail future introductions of thee destructive insect species.

Mitogenomics
The mitochondrial DNA (mtDNA) genome or mitogenome has an effective population size (Ne) one-fourth that of the nuclear genome, which means it is likely to be congruent with termite natural history. There are to date many complete or nearly complete insect mitogenomes sequenced, none of which are termite mitogenomes (Stewart JB, Beckenbach AT. 2003. MPE 26:513-526). Analysis of these mitogenomic sequences provides the ultimate phylogenetic information. Termite mtDNA genome sequence would provide information on gene arrangements, which could be compared with other insect mitogenomes. This comparison coupled with robust phylogenetic analysis would provide strong inference concerning insights into selective pressures on introduced populations. We are using conserved polymerase chain reaction (PCR) primers (Stewart JB, Beckenbach AT. 2003. MPE 26:513-526; Simon C et al. 1994. Ann. Entomol. Soc. Am. 87:651-701) to amplify, sequence and compare subterranean termite mtDNA genomes.

Outreach

I serve as a mentor for the Young Scholars Program in the College of Agricultural and Environmental Sciences. The Young Scholars Program is committed to providing the brightest of our High School Students the opportunity to develop scientific skills by doing research in one of the working research labs on campus. I also serve as a resource for science fair participants and/or as a judge for science fair projects at the school, regional and state level.

Selected Publications

Jenkins, T. M., S. K. Braman, Z. Chen, T. D. Eaton, G. V. Pettis, and D. W. Boyd. 2009. Insights into flea beetle (Coleoptera: Chrysomelidae: Galerucinae) host specificity from concordant mitochondrial and nuclear DNA phylogenies.  Ann. Entomol. Soc. Am. 102: 386-395. PDF

Ruhl, M. W., M. Wolf, and T. M. Jenkins. 2009. Compensatory base changes illuminate morphologically difficult taxonomy. Mol. Phylogenet. Evol. doi:10.1016/j=ympev.2009.07.036  PDF

Jenkins, T. M., T. D. Eaton, and Z. Chen. 2009. Altica litigata (Coleoptera: Chrysomelidae: Galerucinae) morphology: A backdrop for molecular phylogenetic comparisons. Res. Chrysomelidae. 2, 197-206.

Wang, J. L., N. A. Barkley, and T. M. Jenkins. 2009. Microsatellite markers in plants and insects Part I: Applications of biotechnology. Genes, Genomes, Genomics 3, x-y. Invited Review  PDF

Jenkins, T. M., S. C. Jones, C.-Y. Lee, B. T. Forschler, Z. Chen, G. Lopez-Martinez, N. T. Gallagher, G. Brown, M. Neal, B. Thistleton, and S. Kleinschmidt. 2007. Phylogeography illuminates maternal origins of exotic Coptotermes gestroi (Isoptera: Rhinotermitidae). Mol. Phylogenet. Evol. 42: 612-621.  PDF

Lee, C.-Y., B. T. Forschler, and T. M. Jenkins. 2005. Taxonomic questions on Malaysian termites (Isoptera: Termitidae) answered with morphology and DNA biotechnology. Proceedings of the 5th International Conference on Urban Pests, Singapore.

Jenkins, T. M., R. E. Dean, and B. T. Forschler. 2002. DNA technology, interstate commerce, and the likely origin of Formosan subterranean termite (Isoptera: Rhinotermitidae) infestation in Atlanta, Georgia. J. Econ. Entomol 95: 381-389.  PDF

Jenkins, T. M., R. Dean, R. Verkerk, and B. T. Forschler. 2001. Phylogenetic analyses of two mitochondrial genes and one nuclear intron region illuminate European subterranean termite (Isoptera: Rhinotermitidae) gene flow, taxonomy, and introduction dynamics. Mol. Phylogenet. Evol. 20: 286-293.  PDF

Brickman, M .A., T.M. Jenkins, S. A. Clay, and N. H. Granholm. 2001. Genetic variation in Aphthona nigriscutis Foudras (Coleoptera: Chrysomelidae) populations introduced into the United States to biologically control leafy spurge. J. Entom. Sci. 36: 391-401.

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