Research Programs & Interests:
Neuroethological studies of insect olfaction.
One long-term research project that my lab has had is to learn more about the evolution of insect olfaction using a comparative approach involving the sex pheromone communication systems of a variety of species. We perform wind-tunnel experiments to understand how sex pheromone blend alterations affect attraction (upwind flight behavior). We then compare the behavioral results to single-cell recordings from antennal receptor neurons. In the recent past, we have then backfilled the neurons with cobalt dye to stain the olfactory pathways themselves and see where they project to in the antennal lobe of the brain. When called for, we will do more of such neuroanatomy, but now we have become increasingly interested in the adsorption and transport of odorant molecules into the sensillum lumen, followed by transduction into neuronal action potentials (see next section).
Studies to try to learn more about how odorants are adsorbed onto sensilla from the air and transported through cuticular pores into the sensillum lumen:
My laboratory has been working for over ten years on insect-inspired chemosensor development, which has been funded by DARPA, DTRA, USDA/APHIS, and the ONR. We have used the insect antenna plus its basic organules of olfaction, the sensilla, to learn how to better design artificial chemosensors. We have recently emphasized the study of the insect cuticular lipids that coat the sensilla to try to learn their composition and distribution over the antenna and sensilla. We think that if we can figure out how this may help optimize the focusing of odorant molecules into their target pore tubules and into the inside of the sensilla where the sensing elements (dendrites) reside, we can synthetically duplicate this on artificial “sniffers”. We are doing these explorations of cuticular lipids on sensilla with the aid of novel techniques such as atomic force and chemical force microscopy. In addition we are challenging olfactory receptor neurons’ temporal resolution abilities using single neuron recording techniques.
Development of effective novel insect attractants, traps and other detection technologies for agents of harm.
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 aid society. With funding from USDA/APHIS over the past several years, we have worked to understand the mate-finding behavior of the emerald ash borer, an invasive buprestid beetle species, and to try to develop new traps for detecting this pest using our knowledge of the beetle’s behavior. Also, with a separate, PSU/USDA-APHIS cooperative agreement, we have been working to develop a remote-sensing detection system for invasive insect species, which also works for remote chemosensing and reporting of agents of harm that may be heading toward the United States.