Proceedings of the Vertebrate Pest Conference

During the past two decades, remarkable progress has been made in understanding the receptor events for detecting and processing information by the chemical senses (taste, smell and chemical irritation or chemesthesis) of vertebrates. This new information offers expanded opportunities to exploit the chemical senses of vertebrate pests to attract them, repel them, or otherwise modify their behavior in a manner that mitigates their potential to do damage. Here, I describe one example of each of these chemical senses. Irritants are attractive candidates for vertebrate repellents since they activate pain receptors, are innately avoided, and may be relatively non-toxic. Identification of specific irritant receptors and receptor cells has heightened interest in understanding sensory processing and species differences in this chemical sense. Molecular-cellular techniques with isolated cell-based systems can be used to screen for efficacy of irritants in previously uninvestigated species. These techniques can be both predictive and cost effective. Odors: Animals with certain diseases can be identified by an altered body odor. Next steps will include the identification of diagnostic odorants and a broader understanding of mechanisms of the odor message processing. Development of novel sensor devices using detectors such as DNA fragments, pheromone-binding proteins, and immobilized odor receptors may provide breakthroughs in our ability to detect and monitor disease vectors in the natural environment. Tastes: Animal species vary in their sensitivity to taste compounds, presumably as a consequence of ecological selective pressures. For example, cats, obligate carnivores, have no preferences for sweet carbohydrates due to an evolutionary change in a gene responsible for coding for the sweet receptor. Thus, the cat sweet receptor gene has been pseudogenized, presumably as a result of relaxed selection. A better understanding of the molecular biology of taste receptors in a species of interest, be it an endangered animal or a pest such as a pig or deer or coyote, should help in designing novel and effective repellents and attractants.