UC Riverside UC Riverside Electronic Theses and Dissertations Title Improving Sampling Methods and Biological Control for Oligonychus perseae (Acari: Tetranychidae) on `Hass' Avocados (Perseae americana) in Southern California Permalink https://escholarship.org/uc/item/0ch5r576 Author Lara Artiga, Jesus Rikelmy Publication Date 2014 Peer reviewed|Thesis/dissertation eScholarship.org Powered by the California Digital Library University of California UNIVERSITY OF CALIFORNIA RIVERSIDE Improving Sampling Methods and Biological Control for Oligonychus perseae (Acari: Tetranychidae) on ‘Hass’ Avocados (Perseae americana) in Southern California A Dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Entomology by Jesús Rikelmy Antonio Lara Artiga June 2014 Dissertation Committee: Dr. Richard Stouthamer, Co-Chairperson Dr. Mark S. Hoddle, Co-Chairperson Dr. Joseph G. Morse Dr. Daniel J. Jeske Copyright by Jesús Rikelmy Antonio Lara Artiga 2014 The Dissertation of Jesús Rikelmy Antonio Lara Artiga is approved: ___________________________________ ___________________________________ ___________________________________ Committee Co-Chairperson ___________________________________ Committee Co-Chairperson University of California, Riverside ACKNOWLEDGEMENTS I would like to express my deepest gratitude and appreciation to my adviser, Dr. Mark S. Hoddle, for giving me the opportunity to study mites in the California avocado system, always guiding and reviewing my work, encouraging me to do my best, and organizing funding of this research from various agencies. This work was supported in part by a USDA-NIFA Regional Integrated Pest Management Competitive Program grant (2010-34103-21202), the University of California Hansen Trust, and the California Avocado Commission. Additional financial support was provided to me from the Robert van den Bosch Scholarship in Biological Control, UC Riverside Eugene Cota-Robles Fellowship, UC Riverside Graduate Division Fee Fellowship, UC Alliance for Graduate Education and the Professoriate Fellowship, Herbert Kraft Scholarship, Harry Scott Smith Biological Control Scholarship, and the UC Riverside Graduate Student Association Travel Grant Program. I am grateful to the award committees who presented me with this vital funding because it allowed me to focus on my research and attend several conferences to communicate my findings to the public, researchers, growers, and pest managers. My field work would not have been successful without the help of numerous growers who provided me unlimited access to their avocado orchards. I am also indebted to Ruth Amrich, Martin Castillo, Naseem Sasermi, Allison Bistline-East, John Jones, Nick Salvato, and Mike Lewis for assisting me with field work and processing avocado leaf samples in the laboratory. It has been a pleasure working with all of them and I will always cherish the memories of our lively conversations. iv I would like to sincerely thank the members of my dissertation committee, Drs. Daniel Jeske, Richard Stouthamer, and Joseph Morse for their guidance and support of this work. Dr. Jeske and his former graduate students, Drs. Elijah DePalma and Judy Li, provided indispenable insight into the spatial dynamics of spider mites in the avocado system. My understanding of the theory and application of biological control improved greatly while taking several courses taught by Dr. Stouthamer. Dr. Morse provided me with valuable advice for improving the clarity and organization of this work. I also acknowledge Drs. Jan Nyrop, Steve Naranjo, and Matt Daugherty for taking the time to speak to me about statistical modeling which helped me streamline the data analysis methods I used. Dr. Paul Rugman-Jones kindly assisted me with the molecular work I describe in the first chapter of this dissertation. In addition, I would like to give a big, warm “Thank You!” to Drs. Hugo Aguilar Piedra and Menelaos Stavrinides for instructing me in the principles of acarology when I was still completing my bachelor’s degree from UC Berkeley. Although this occurred many years ago, their invaluable mentorship afforded me many lasting lessons that helped me move forward with my research on spider mites and phytoseiids during graduate school. In particular, Dr. Aguilar taught me that biological control of spider mites is not a simple matter and Dr. Stavrinides motivated me to learn how to use statistics software. Finally, I would like to extend my heartfelt appreciation to La-Keeya Loman, Joy Ashburn, and Adena Why for offering me their sincere friendship. When I think of them, Andrew Gold’s song, “Thank you for being a friend,” best expresses how I feel. v DEDICATION To my parents, Alirio and Elsa, for always being there for me. vi ABSTRACT OF THE DISSERTATION Improving Sampling Methods and Biological Control for Oligonychus perseae (Acari: Tetranychidae) on ‘Hass’ Avocados (Perseae americana) in Southern California by Jesús Rikelmy Antonio Lara Artiga Doctor of Philosphy, Graduate Program in Entomology University of California, Riverside, June 2014 Dr. Richard Stouthamer, Co-Chairperson Dr. Mark Hoddle, Co-Chairperson Oligonychus perseae Tuttle, Baker and Abattiello (Acari: Tetranchidae) is a foliar spider mite pest of avocados, Persea americana Miller (Lauraceae), and both are native to Mexico. In California, O. perseae can cause significant premature defoliation to Hass avocados which is most important commercial avocado cultivar in the world market. Recent work form Israel has shown that extensive foliar injury caused by populations of O. perseae on Hass foliage can translate into fruit yield reduction. Consequently, there is warranted concern over the damage from O. peseae populations in other Hass producing areas such as Spain, Israel, and Costa Rica, but also within its home range in Mexico. vii In California, great effort has been placed in developing and implementing an integrated pest management program for O. perseae, but improvements are still needed for effective control of this pest in commercial Hass orchards. In particular, the success of releases of commercially-available phytoseiids as part of an inoculation biological control program has been limited, the role of resident phytoseiids for control of O. perseae is not well understood, and effective research-based sampling plans to monitor the activity of O. perseae and resident phytoseiids are not available. Consequently, the motivation for conducting the work presented in the five chapters of this dissertation was to address these limitations. The first chapter provides insight into the trophic interactions between O. perseae and natural enemies in California Hass avocados. This information can be used to improve the current biological control program of O. perseae in California and potentially other avocado systems where this spider mite occurs. The second chapter examines the limitations of the current sampling guidelines recommended for assessing O. perseae densities. The third chapter focuses on the development and validation of a binomial sampling plan for O. perseae that minimizes the counting effort and could be used by pest control advisers to monitor levels of this pest in commercial orchards. The fourth chapter compares the performance of enumerative and binomial sampling plans to monitor populations of resident phytoseiids that feed on O. perseae. Finally, the fifth chapter examines the role of resident phytoseiid populations in controlling field populations of O. perseae over a 10-year period. viii Table of Contents Chapter 1 Past, Present, and Future: Biological Control of Spider Mites on California Avocados……………………………………………...….1 Abstract ……………………………………………………………………….….2 Section 1.1 Introduction to Spider Mite Biological Control on California Avocados………………………………..................................................4 Section 1.2 Historical Concerns with Avocado Pests in California……...................10 Section 1.3 Economic Importance of Early Spider Mites Associated with California Avocados…………………………………………………....14 1.3.1 Success of Early Spider Mite Biological Control Efforts on California Avocados…………………………………………….…..15 Section 1.4 Introduction of Oligonychus perseae into the California Avocado System ……………………………………………...…...…...19 1.4.1 General Biology of Oligonychus perseae on Avocados……......22 Section 1.5 Potential Factors that Explain the Economic Importance of Oligonychus perseae on Avocados in California ……………….……..24 1.5.1 Acreage Expansion of Hass Avocados………………….……...25 1.5.2 Susceptibility of the Hass cultivar to Spider Mites and other Arthropods……………………………………….……….28 1.5.3 The Implication of Chemical Profiles of Avocado Cultivars in Relation to Herbivory and Biological Control………………35 ix Section 1.6 Present Biological Control Program of Oligonychus perseae Using Phytoseiids in California…………………………………..……40 1.6.1 Natural Control Using Euseius hibisci…………………………41 1.6.2 Augmentative Biological Control using Neoseiulus californicus………………………………………...43 1.6.3 Conservation Biological Control using Euseius spp…...............45 Section 1.7 Future Prospects for Improving Biological Control of Oligonychus perseae in California…………………………………….46 1.7.1 Classical Biological Control Using Phytoseiids……………….49 1.7.2 Biological Control Using Stigmaeids………………….............52 1.7.3 Cultivar Improvements in California for Pest Control………...62 References Cited……….…………………………………………………………...…66 Figure Legends………………………………………………………………………...77 Figures………..………………………………………………………………………..78