Tom Baker
Professor

The Pennsylvania State University
105 Chemical Ecology Lab
University Park, PA 16802

Phone: 814-863-4435
FAX: 814-863-4439
Email: tcb10@psu.edu

Current Graduate Students:

Jon Lelito
Loyal Hall

Link to: Center for Chemical Ecology

Education:

B.S. Entomology Cornell University 1972
M.S. Entomology Cornell University 1975
Ph.D. Entomology Michigan State University 1979

International Programs/Experience:

Councilor for the Asia-Pacific Association of Chemical Ecologists

Department Focus Area:

Chemical Ecology

Research Interests :

Insect Pheromones and Odor-Mediated Behavior
Neuroethological Studies of Olfaction
Identification and Development of Insect Attractants for IPM Systems
Development of Olfaction-Based Biosensors

Research Programs & Interests:

Neuroethological studies of heliothine moth sex pheromone and host plant volatile mixture interactions:

One long-term research project that my lab has been involved in with funding from the USDA/NRI and from NSF, has been to understand insect olfaction using a comparative approach involving heliothine moth species and their sex pheromone communication systems. We perform wind-tunnel experiments to understand how sex pheromone blend alterations affect moth upwind flight behavior. We compare the behavioral results to single-cell recordings from antennal receptor neurons. In addition, we backfill the neurons with cobalt dye to stain the olfactory pathways themselves and see where they project to in the antennal lobe of the brain. Recently we found an unexpected interaction between pheromone components and floral odors that points to an increased role of antennal neurons in processing odor mixtures before being sent to higher analysis centers.

Research and development of a discriminating insect-antenna-based olfactory biosensor:

My laboratory has been working on a project over the past six years or so, funded first by DARPA for four years, to develop a highly sensitive tissue-based biosensor that can detect, discriminate and locate agents of harm such as unexploded land mines and other ordinance, drugs, and toxins. Our biosensor, called the Quadro-Probe uses an array of insect antennae that reports differential patterns of excitation when placed in the odor plumes emanating from different types of odor sources many tens of meters upwind. What is exciting about this biosensor is not only in its potential for detecting and locating agents of harm, but also in what it is revealing to us about odor plumes and insects' olfactory capabilities. A computer algorithm developed in conjunction with collaborators at the University of Illinois -Chicago now allows the biosensor to perform its odor-discriminating feats in real time. After an initial training session of approximately 30 seconds, the biosensor's probe placed in odor plumes coupled with the algorithm all operating in real-time, has been shown to recognize individual odor strands in the plume as a specific odor with 80-100% correct signal identification.

Development of effective novel insect attractants, traps and mating disruption dispensers:

For a long time now, our lab's philosophy has been that the land grant university mission requires that agricultural experiment station researchers such as ourselves work to deliver useful technologies and information to the people of our state. Thus one major element of my lab's research continues to be to try to isolate and identify useful new attractants and other behavior-modifying chemicals and help develop them into technologies that are available in the marketplace. Our work over the past 5 - 10 years or so along these lines has resulted in a novel housefly attractant, a new Drosophila fruit fly attractant, and a new lacewing and ladybeetle attractant that are being, or have been, developed into new commercial products for use in and around the home. In addition, we have developed and commercialized four new mating disruptant formulations for use against the European cornborer, oriental fruit moth, and two moth pests of cranberry, respectively. These products are all listed as acceptable for use in organic practice by the Organic Materials Review Institute.

Relevant Publications:

Ochieng, S.A., K. Poole, W.L. Roelofs, N.J Vickers, C.E. Linn,Jr., and T. C. Baker 2003. Unusual pheromone receptor neuron responses in heliothine moth antennae derived from inter-species imaginal disc transplantation. J. Comp. Physiol. A. 189: 19-28.

Baker, T. C. 2002. Mechanism for saltational shifts in pheromone communication systems. Proc, Nat. Acad. Sci. USA. 99: 13368-13370.

Park, K. C., Ochieng', S.A., Zhu, J., and T. C. Baker. 2002. Odor discrimination using insect electroantennogram responses from an insect antennal array. Chem Senses 27:343-352.

Ochieng', S. A. and T. C. Baker. 2002 Host plant volatiles synergize responses of sex pheromone-specific olfactory receptor neurons in male Helicoverpa zea. J. Comp. Physiol. A 188: 325-333.

Vickers, N. J., Christensen, T. A., Baker, T. C., and J. G. Hildebrand 2001. How do odour plume dynamics influence the brain's olfactory code? Nature (London) 410: 466-470.

Zhu, J., Park, K.-C., Ochieng, S. A., Unelius, R. C., Obrycki, J. J., and T. C. Baker. 2000. Identification of (Z)-4-tridecene from defensive secretion of green lacewing, Chrysoperla carnea. J. Chem. Ecol. 26: 2421-2434.

Cossé, A. A. and T. C. Baker. 1999. Electrophysiologically and behaviorally active volatiles of buffalo gourd root powder for corn rootworm beetles. J. Chem. Ecol. 25: 51-66.

Zhu, J., A. A. Cossé, J. J. Obrycki, K.S. Boo and T. C. Baker. 1999. Olfactory reactions of the twelve-spotted lady beetle, Coleomegilla maculata and the green lacewing, Chrysoperla carnea to semiochemicals released from their prey and host plant: Electroantennogram and behavioral responses. J. Chem. Ecol. 25:1163-1177.

Quero, C. and T. C. Baker 1999. Antagonistic effect of (Z)-11-hexadecen-1-ol on the pheromone-mediated flight of Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae). J. Insect Behav. 12: 701-709.

Baker, T. C., H. Y. Fadamiro, and A. A. Cossé. 1998. Moth uses fine tuning for odour resolution. Nature (London) 393: 530.