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Thomas Holtzer

holtzertomDepartment Head


Office: C129A Plant Sciences

970-491-5843 office








Research Interests:

As Department Head, my primary commitment is to administration of the department’s classroom teaching, research, and outreach/extension programs. Additional administrative responsibilities include service as Director of Colorado State University’s Center for Bioinformatics, Cluster Leader for Decision Support Systems and Bioinformatics within the CSU Infectious Disease Supercluster and membership on the Supercluster’s Management and Oversight Committee.

In addition, I continue direct, active involvement in research and teaching, including advising graduate students in Agricultural Biology and the Graduate Degree Program in Ecology. In research, my emphasis is in Integrated Pest Management as a component of dryland cropping systems and in the migration, dispersal, biological control, and landscape-scale ecology of Russian wheat aphid.

In recent years I have become increasingly involved in developing interdisciplinary teams to address research and outreach needs related to complex agricultural and natural resource problems. An outgrowth of this interest resulted in me serving as coordinator of the grant-funded Lower South Platte Irrigation Research and Development Project. The primary focus of this work is to develop and investigate cropping system options that meet two goals: use less water that can be made available for meeting increasing urban water needs but at the same time sustain viable economic returns to the agricultural and rural sectors.

In the classroom, I began co-teaching the undergraduate course AGRI/PHIL 330 Agricultural Ethics in spring 2006. This course begins with discussions of major ethical theories and continues with analysis of key agricultural issues (such as pesticide, genetically modified crop plants and animals, and water) from the perspectives of these theories.

In addition to my CSU involvements, I am active in the Entomological Society of America, where I served two terms on the Governing Board. I also have recently served on the Board of Directors of the Council for Agricultural Science and Technology (CAST). Currently, I serve as Co-director of the USDA / NIFA funded Western Integrated Pest Management Center and am a member of the national ESCOP-ECOP/APLU Pest Management Strategies Subcommittee.


Courses I Teach:

AGRI/PHIL 330: Agricultural and Food Systems Ethics (Spring)


Selected Publications:

Merrill, S. C., T. O. Holtzer, F. B. Peairs, P. Lester. 2009. Modeling spatial variation of Russian wheat aphid overwintering population densities in Colorado winter wheat. J. Econ. Entomol. 102(2): 533-541

Merrill, S. C., T. O. Holtzer, F. B. Peairs. (In Press). Russian Wheat Aphid, Diuraphis noxia (Kurdjumov), reproduction and development with a comparison of intrinsic rates of increase to other important small grain aphids: a meta-analysis. Environ. Entomol.

Elliott, N.C., G.L. Hein, M.C. Carter, J.D. Burd, T.O. Holtzer, and J.S. Armstrong. 1998. Russian wheat aphid ecology and modeling in Great Plains agricultural landscapes. In Quisenberry, S.S. and F.B. Peairs (eds.) Response Model for an Introduced Pest – The Russian Wheat Aphid. Thomas Say Publications in Entomology. Entomological Society of America, Lanham MD, pp. 31-64.

Mohamed, A.H., P.J. Lester, and T.O. Holtzer. 2000. The abundance and effects of predators and parasitoids of the Russian wheat aphid, Diuraphis noxia (Mordvilko) (Homoptera: Aphididae), under organic farming conditions in Colorado. Environ. Entomol. 29:360-368.

Lester, P.J. and T.O. Holtzer. 2002. Patch and prey utilization behaviors by Aphelinus albipodus and Diaeretiella rapae (Hymenoptera: Aphelinidae and Aphidiidae) on Russian wheat aphid (Homoptera: Aphididae). Biological Control 24: 183-191.

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