NOTE TO USERS This reproduction is the best copy available. UMI Acoustic communication in the Mountain Pine Beetle, Dendroctonus ponderosae Hopk. (Coleoptera: Scolytidae): Characterization of signals and anatomy By Alan J. Fleming A dissertation submitted to the faculty of Graduate Studies in partial fulfillment of the requirements for the degree of Master of Science in Biology Carleton University Ottawa, Ontario 2009 © Library and Archives Bibliothgque et 1*1 Canada Archives Canada Published Heritage Direction du Branch Patrimoine de l'6dition 395 Wellington Street 395, rue Wellington Ottawa ON K1A 0N4 Ottawa ON K1A 0N4 Canada Canada Your file Votre reference ISBN: 978-0-494-68616-4 Our file Notre r6f6rence ISBN: 978-0-494-68616-4 NOTICE: AVIS: The author has granted a non- L'auteur a accorde une licence non exclusive exclusive license allowing Library and permettant a la Bibliotheque et Archives Archives Canada to reproduce, Canada de reproduire, publier, archiver, publish, archive, preserve, conserve, sauvegarder, conserver, transmettre au public communicate to the public by par telecommunication ou par I'lnternet, preter, telecommunication or on the Internet, distribuer et vendre des theses partout dans le loan, distribute and sell theses monde, a des fins commerciales ou autres, sur worldwide, for commercial or non- support microforme, papier, electronique et/ou commercial purposes, in microform, autres formats. paper, electronic and/or any other formats. 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I+I Canada i Abstract Mountain Pine Beetles, (.Dendroctonus ponderosae Hopkins employ sounds for intra- and inter-specific communication. Signals associated with three behavioural contexts were analyzed. Analysis of signals revealed air- and solid-borne components. Airborne signals were found to have an average intensity of 55.71 dB at 2 cm, while solid-borne signals showed an average velocity of 2.76 ± 0.93 mm/s at 1 cm. Airborne signals were broadband between 6.5 kHz - 83.3 kHz, with energy divided into up to 5 energy peaks. Comparisons between signal types revealed differences in the frequency distribution, and dominant frequencies. Solid-borne components of the signals showed frequencies between 4.6 kHz and 22.8 kHz. Examinations of gross anatomy revealed a putative candidate for tympanal ear present on the dorsal meta thoracic surface of the animal. Preliminary behavioral trials conducted, using manipulated natural signals in artificial settings, elicited an acoustic behavioral response. ii Acknowledgments I would like to thank my committee, Dr. Sue Bertram, Dr. Michael Jonz, and my supervisor Dr. Jayne Yack for their suggestions and recommendations. I would like to extend a further and heartfelt gratitude to Dr. Jayne Yack for the amazing opportunity she has provided me by accepting me and allowing me to complete a Masters degree with her. Working for Dr. Yack has been a life changing experience, filled with excitement and wonder. Through the many years I have spent in the Yack lab I have come to regard all of its many members as members of my own extended family. I therefore would like to offer my gratitude and love to all members of the Yack lab, past and present. Especially, Veronica Bura, Jaclyn Scott, Sarah Bond, J.P. Fournier, Ombor Mitra, Sen Sivalingham, Tiffany Ebberhard, and Dr. Jeff Dawson. You guys have been instrumental to my degree I thank you for your support and assistance when it was required. Special thanks to Dr. Alan Carroll, Greg Smith and Doug Linton from the Pacific Forestry Division of the NRCan, in British Columbia, for providing me with all my specimens of Dendroctonus ponderosae. I would like to thank my parents Luisa and Alan Fleming for their support and encouragement. Throughout my life they always provided me with an environment which nurtured my love of all things insect. I would also like to give a special thank you to Dr. Stewart Peck, who was instrumental in my academic pursuits, and my passion towards the field of entomology. I would like to thank all the funding sources afforded to Dr. Jayne Yack which have made this research possible: Early Researcher Award (ERA), Natural Science and Engineering Research Council (NSERC), and the Canadian Foundation for Innovation (CFI). iii Table of Contents Abstract i Acknowledgments ii Table of Contents iii List of Tables v List of Figures vi Chapter 1. Introduction 1 1.1 General Introduction 2 1.2 The Mountain Pine Beetle - Life History in Brief 4 1.3 Objectives 11 Objective: Signal Characterization 11 Objective: Receptor Morphology 12 Objective: Behavioural Playbacks 14 Chapter 2. Signal Characterization 15 2.1 Introduction 16 General Introduction on Sound Production 16 Acoustic Communication in Dendroctonus ponderosae 17 2.2 Methods 24 Animals 24 Recording Preparations 24 Stress Sounds Set-up 28 Male-female Interactions Set-up 28 Male-male Interactions Set-up 29 Signal Analysis 30 Sound Pressure Level of Airborne Sounds 31 Calibration of Vibrational Signal Velocity 32 2.4 Results 33 Stress Sounds 33 Male-Female Interactions 43 Male-Male Interactions 55 Comparisons between signals 63 2.5 Discussion 74 General Discussion on Sound Production 74 Male-female Interactions 76 Male-male Interactions 79 Substrate Borne Vibrations 81 Chapter 3. Anatomy and Putative Receptor Structures of Dendroctonus ponderosae 84 3.1 General Introduction on Anatomy 85 iv 3.2 Methods 92 Animals 92 External and General Anatomy of Dendroctonus ponderosae 92 Light Micrographs of External Anatomy of Dendroctonus ponderosae. 94 Nervous System Dissection of Dendroctonus ponderosae 94 3.3 Results 103 External Anatomy 103 Putative receptor structures in Dendroctonus ponderosae. 106 Nervous System Anatomy 115 3.4 Discussion 128 Near-field Receptors. 128 Vibration Receptors.. 129 Far-field Receptors.... 130 Chapter 4. Playbacks. 132 4.1 Introduction 133 Male-male Signals 135 Male-female Signals.. 135 4.2 Methods 137 Animals 137 Signal Preparation. 137 Signal Playback 138 Male Setup 147 Female Setup 148 4.3 Results 149 Male-male Interactions 149 Male-female Interactions. 153 4.4 Discussion 156 Chapter 5. General Discussion. 158 5.1 General Discussion 159 References 162 ix List of Tables Table 2.1 Summary of sound production within the genus Dendroctonus 20 Table 2.2 Summary of temporal and spectral statistics of airborne sounds in D. ponderosae 39 Table 2.3 Summary of temporal and spectral statistics of vibrational signal components 54 Table 4.1 Summary of results ofplayback study in D. ponderosae 152 vi List of Figure Captions Figure 1.1 Repertoire of sounds in D. ponderosae 7 Figure 1.2 Galleries ofD. ponderosae 9 Figure 2.1 Scanning electron micrographs of the sound producing structures in D. ponderosae 22 Figure 2.2 Methods for recording acoustic signals from male D. ponderosae 26 Figure 2.3 Simple stress chirps 35 Figure 2.4 Complex stress chirps 37 Figure 2.5 Mean percent intensity decay for airborne stress signals 41 Figure 2.6 One male-female trial showing sequence of events occurring in a typical trial 46 Figure 2.7Airborne complex male-female chirps 48 Figure 2.8 Vibratory component of male-female chirps 50 Figure 2.9 Histogram showing the change in signal type (simple vs. complex) over time 52 Figure 2.10 Airborne male-male D. ponderosae chirps 57 Figure 2.11 Vibratory component of male-male chirps 59 Figure 2.12 Mean percent decay of amplitude of solid borne male-male signals 61 Figure 2.13 Histogram showing distribution of frequency peaks for simple chirps across chirp types 66 Figure 2.14 Histogram showing distribution offrequency peaks for complex chirps across chirp types. ...68 Figure 2.15 Sliding scale histograms showing peak frequency distribution across three simple signals.... 70 Figure 2.16 Sliding scale histograms showing peak frequency distribution across three complex signals. 72 Figure 3.1 Dorsal dissection of female D. ponderosae 96 Figure 3.2 Ventral dissection ofD. ponderosae male 101 Figure 3.3 General external anatomy ofD. ponderosae 104 Figure 3.4 Detailed anatomy of the leg ofD. ponderosae 107 Figure 3.5 Putative Johnston's organ on a D. ponderosae female head 110 Figure 3.6 Putative thoracic receptor structures on D. ponderosae 113 Figure 3.7 Drawings of the brain of D. ponderosae 117 Figure 3.8 Light micrographs and drawings of the subesophageal ganglion 120 Figure 3.9 Light micrographs of the thoracic ganglia in D. ponderosae 123 Figure 3.10 Schematic drawing of the entire ventral nerve cord in D. ponderosae 126 Figure 4.1 Oscillograms of the signals used in the playback experiments 141 Figure 4.2 Experimental setup for playbacks 143 Figure 4.3 Comparison ofplayed back versus original signals of a male-female complex interaction 145 Figure 4.4 Oscillograms of stimulus and acoustic response during male-male playback 150 Figure 4.5 Oscillograms of stimulus and acoustic response during male-female playback 154 1 Chapter 1. Introduction 2 1.1 General Introduction Bark beetles (Scolytidae: Curculionoidea) pose one of the largest insect threats to North American coniferous forests.