FIELD AND LABORATORY STUDIES ON THE EFFECTS OF HOST FRUIT VOLATILES ON RHAGOLETIS MENDAX (DIPTERA: TEPHRITIDAE) ADULTS by Agnieszka Beata Kwasniewska Department of Natural Resource Sciences McGill University, Montreal, Quebec May 2009 A thesis submitted to McGill University in partial fulfillment of the requirements of the degree of Master of Science © Agnieszka Kwasniewska 2009 0 Table of Contents List of Tables...........................................................................................................3 List of Figures..........................................................................................................4 Acknowledgements..................................................................................................5 Preface......................................................................................................................6 Contribution of Authors...........................................................................................7 Abstract....................................................................................................................8 Résumé.....................................................................................................................9 Dedication..............................................................................................................10 CHAPTER 1 - GENERAL INTRODUCTION AND LITERATURE REVIEW................................................................................................................11 1.1. Biology of Rhagoletis mendax..........................................................12 Hosts...............................................................................................12 Life cycle........................................................................................13 Distribution....................................................................................14 Diet.................................................................................................14 Learning.........................................................................................14 Natural enemies..............................................................................15 1.2. Host location and volatiles................................................................16 Visual host cues.............................................................................16 Olfactory host cues and olfactory receptor neurons......................16 Other volatiles................................................................................17 1.3. Population studies.............................................................................18 1.4. Monitoring and Management............................................................19 Pherocon-AM traps........................................................................19 Sphere traps....................................................................................20 IPM and pesticides.........................................................................21 Gamma irradiation.........................................................................22 1.5. General objectives and research questions........................................23 1.6. Literature cited..................................................................................26 Connecting statement.................................................................................34 1 CHAPTER 2 - EFFECTS OF HOST FRUIT VOLATILES ON FIELD CAPTURES OF BLUEBERRY MAGGOT, RHAGOLETIS MENDAX, ADULT FLIES (DIPTERA: TEPHRITIDAE) USING GREEN SPHERE TRAPS...................................................................................................................35 2.1. Abstract..................................................................................35 2.2. Introduction............................................................................36 2.3. Materials and Methods...........................................................38 2.4. Results....................................................................................40 2.5. Discussion..............................................................................41 2.6. Literature cited.......................................................................44 Connecting statement.................................................................................51 CHAPTER 3 - EFFECTS OF HOST FRUIT VOLATILES ON THE OLFACTORY RESPONSES OF RHAGOLETIS MENDAX (DIPTERA: TEPHRITIDAE) FLIES.........................................................................................52 3.1. Abstract..................................................................................52 3.2. Introduction............................................................................53 3.3. Materials and Methods...........................................................56 3.4. Results....................................................................................61 3.5. Discussion..............................................................................63 3.6. Literature cited.......................................................................67 CHAPTER 4 – GENERAL CONCLUSIONS.......................................................78 4.1. Literature cited.......................................................................80 2 LIST OF TABLES Table 2.1: Blends of various classes of volatile compounds that were extracted from ripe host fruit and were found in both black huckleberries (Gaylussacia baccata) and lowbush blueberries (Vaccinium angustifolium). Courtesy of S. Gaul (AAFC/Kentville, NS)..................................................................................47 Table 3.1: Mixtures of different classes of volatile chemicals that were extracted from the headspace of ripe huckleberries (Gaylussacia baccata) and lowbush blueberries (Vaccinium angustifolium). Courtesy of S. Gaul (AAFC/Kentville, NS).........................................................................................................................72 Table 3.2: ANOVA results (F and p-values) in wind tunnel bioassays for Rhagoletis mendax. Behaviours were recorded for 20 minutes, for 9 different treatment blends of volatiles extracted from ripe host fruit. Active time in the tunnel was calculated by subtracting the total time spent in tunnel from inactive moments (Relative time = total time – time spent grooming – time spent sitting). Frequency of flight was recorded every time lift off from the surface occurred. Nova Scotia and Quebec population results included data for naive flies only (A). Nova Scotia population data includes previous experience with host fruit (B)..........................................................................................................................73 Table 3.3: Results for contingency table analysis between the three sections of the wind tunnel and each of the nine treatment blends of volatiles extracted from ripe host fruit. + indicate that the behaviour has a significantly higher deviation from the expected value occurring in the tunnel section for that treatment (Chi squared value > 3.84). - indicate that the behaviour has a significantly lower deviation from the expected value occurring in the tunnel section for that treatment (Chi squared value > 3.84). Blank cells indicate no significant effect was present.............................................................................................................74 3 LIST OF FIGURES Figure 2.1: Location of green sphere traps in and around the Réserve Écologique du Pin-Rigide, Saint-Chrysostome, Quebec, July-August, 2008. Symbols of different size represent the number of flies captured. Changes in greyscale indicate different blocks. Inset graph shows the field location in the Province of Quebec, Canada.....................................................................................................48 Figure 2.2: Mean (± SE) of fly captures for each day of sampling for all treatments. Collections took place at Reserve Ecologique Pin-Rigide, Saint- Chrysostome, Quebec. A total of 72 traps were checked twice weekly from 4 July 2008 until 29 August 2008.....................................................................................49 Figure 2.3: Mean (+ SE) of R. mendax fly captures during the earlya (A) and lateb (B) phases of the season. Different letters indicated a significant difference between treatments. See Table 2.1 for definition of treatments. a Early season occurs during the month of July. b Late season occurs during the month of August....................................................................................................................50 Figure 3.1: Wind tunnel (100 by 30 by 30 cm: L,W, H). 1) charcoal filter; 2) location of lure; 3) location of fan generating air current, as well as exhaust tube; 4) sub-division between tunnel sections; 5) artificial vegetation; 6) release area; 7) direction of air flow................................................................................................75 Figure 3.2: Mean (+ SE) for active time for R. mendax adults in response to different treatments within the wind tunnel. See Table 2.1 for definition of treatments. Different letters indicated a significant difference between treatment (Tukey‟s post hoc test)...........................................................................................76 Figure 3.3: Mean (± SE) for frequency of flight for R. mendax male and female adults