Neuroethology of Acoustic Communication in Larval and Adult Insects

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The long-term objective of my NSERC research program is to explain how animals' sensory systems are adapted to natural environments. Sensory organs are crucial for the day-to-day functioning and survival of all animals (including humans) playing integral roles in communication, orientation, and predator detection. In my Neuroethology & Bioacoustics Facility we study the acoustic sensory `worlds' of (primarily) insects. Insects have an amazing diversity of sensory organs that detect and process acoustic (sound and vibration) signals extending far beyond human sensory capabilities. We employ specialized instruments and methods to tap into these communication channels and identify novel sensory organs. This program has supported cutting edge, internationally recognized research, including the discoveries that nocturnal butterflies possess ultrasound-sensitive `bat detecting' ears, that caterpillars communicate through plant vibrations, and that earthworms surface in response to ground vibrations. **The proposed research will build upon this success by focusing on butterflies, caterpillars and bark beetles- insects whose acoustic sensory capabilities are poorly understood. BUTTERFLY behaviour has been extensively researched and has contributed significantly to models of animal migration and global warming. While butterfly visual and chemical senses have been studied at length, surprisingly little is known about their hearing. We have shown that many species possess tiny ears on their wings. We will test the hypothesis that these ears function as `bird detectors' and examine the neurophysiological mechanisms that allow a butterfly to detect and localize sounds in its environment. This research will expand our knowledge of the sensory ecology of insects, and will provide insights into the biomechanical, neurophysiological and neuroanatomical characteristics of these unusual `wing ears'. CATERPILLARS are of significant ecological and economic importance to Canada as forest and agricultural pests, yet, fundamental questions about how these insects sense and interact with their environment remain unanswered. We will explore the functions of acoustic signalling and hearing. For example, we will test the intriguing hypothesis that larvae create `vibratory fences' to space themselves on their host plants, and that specialized elongated `hairs' in monarch butterfly caterpillars function as hearing organs to detect predators. We will also identify novel vibration receptors in territorial caterpillars that compete using vibrations. This research will provide unprecedented insights into the communication systems of all larval insects, including those of honey bees, flies, beetles and moths. BARK BEETLES such as the mountain pine beetle and dutch elm beetle impose significant threats to Canadian forests. We have shown that they are acoustically active beneath tree bark in the sap layer where they make galleries that eventually kill the tree. We will test hypotheses on the roles of these signals in bark beetle survival, and will identify for the first time their acoustic sensory organs.**Research on insect acoustic communication contributes to our knowledge of animal behaviour, neuroscience and entomology, and has practical applications for pest management, robotics and human health. Discovering and characterizing novel sensory organs will provide inspiration for developing miniature sensing devices and tools for pest control. Importantly, the proposed research will train HQP at all career stages in skills such as neurophysiology, microscopy, computer programming, videography, bioacoustics, and molecular genetics, preparing them for careers in forest and agricultural entomology, engineering, education, and environmental and health sciences.