UC Riverside UC Riverside Electronic Theses and Dissertations Title Myoporum Thrips Life History, Host Preference, and Biological Control Permalink https://escholarship.org/uc/item/33r975jm Author Shogren, Chris Publication Date 2017 Peer reviewed|Thesis/dissertation eScholarship.org Powered by the California Digital Library University of California UNIVERSITY OF CALIFORNIA RIVERSIDE Myoporum Thrips Life History, Host Preference, and Biological Control A Dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Entomology by Christopher John Shogren December 2017 Dissertation Committee: Dr. Timothy D. Paine, Chairperson Dr. Matthew P. Daugherty Dr. Richard A. Redak The Dissertation of Christopher John Shogren is approved: Committee Chairperson University of California, Riverside Copyright by Christopher Shogren 2017 Acknowledgements I would like to express my sincere thanks to Dr. Tim Paine for his guidance and support throughout this project. Thank you to my committee members, Dr. Matt Daugherty and Dr. Rick Redak, for their valuable advice regarding experimental design and data analysis. The members of the Paine lab- Chris Hanlon, Colin Umeda, Rebecca Watersworth, Gabby Martinez, Giovanna Munoz, Pamela Hsi, and Rory McDonnell- provided assistance throughout my study an allowed me to progress with some sanity. A big thank you to Erich Schoeller and Fatemeh Ganjisaffar, without your statistical expertise I would never have made it this far. Thank you to D. Horton, T. Lewis, and R. Vetter for providing assistance identifying predators. Chris Martinez and the staff at the SCREC provided assistance with the field trial; their assistance during this project was greatly appreciated. Thank you to my brother Charles for digging holes in the scorching heat, and helping build fantastic cages. Thank you to Cottonwood Growers for providing space for field trials. Financial support was received in part by the California Association of Nurseries and Garden Centers, the Harry Scott Smith Fund, and the Robert van den Bosch Scholarship. In addition to the persons and organizations mentioned above, many people provided personal support that was essential for my coming to and successfully graduating from UCR. My friends, from life before UCR as well as those made here, are constant sources of inspiration and gratification. Finally, I would like to express my deepest gratitude to my family for their loving support. iv Dedications To my daughter Mia To my family To my friends And In loving memory of, Agnes Shogren v ABSTRACT OF THE DISSERTATION Myoporum Thrips Life History, Host Preference, and Biological Control by Christopher John Shogren Doctor of Philosophy, Graduate Program in Entomology University of California, Riverside, December 2017 Dr. Timothy D. Paine, Chairperson Temperature-driven development of myoporum thrips, Klambothrips myopori, (Thysanopetra: Phlaeothripidae) was examined at seven constant temperatures (15°, 17°, 20°, 25°, 30°, 34°, and 35.5° C) on Myoporum laetum. Thrips successfully completed development to adult stage between 15 and 35.5°C. One linear and three nonlinear models were fitted to describe developmental rates of K. myopori as a function of temperature, and for estimating thermal constants and bioclimatic thresholds (Tmin, Topt and Tmax). The Briere-1 model performed best in describing the developmental rate of cumulative life stages. Two ecological niche models, CLIMEX and Maxent, were used to predict the geographic distribution of K. myopori in its native range and globally. Overall predictions of environmental suitability differed greatly across models. The CLIMEX model accurately predicted known invasive and native localities, while the Maxent model failed to predict vi the native localities and parts of the invasive range. Based on the CLIMEX model, K. myopori has the potential to establish in many regions of the globe. Using field studies and laboratory feeding tests, we identified Myoporum laetum and M. ‘Pacificum’ as key host plants of K. myopori. In laboratory trials, K. myopori failed to complete development on M. ‘Clean n Green’ and M. ‘Putah Creek’. For the six varieties of Myoporum tested, K. myopori damage was only observed on M. laetum and M. ‘Pacificum’. Although K. myopori can successfully colonize and reproduce on several varieties of Myoporum, they demonstrated a preference for M. laetum and M. ‘Pacificum’ in laboratory and field trials. Using field and laboratory studies, we identified Orius spp. (Hemiptera: Anthocoridae), Chrysoperla spp. (Neuroptera: Chrysopidae), Syrphidae, and Salticidae as possible key natural enemies of K. myopori in southern California. Laboratory studies determined the consumption rates of Orius insidiosus and Chrysoperla rufilabris at constant densities of K. myopori and defined the functional response of the predators. Both predators consumed more 2nd instar larvae than other prey stages. O. insidious displayed a type II functional response, while C. rufilabris displayed both type II and type III depending on prey stage, implying the predators should be most effective at suppressing thrips populations at lower densities. vii Table of Contents Acknowledgements……………………………………………………………….iv Dedications………………………………………………………………………..v Abstract of the Dissertation………………………………………………………vi List of Tables……………………………………………………………………...x List of Figures…………………………………………………………………....xii Chapter 1. Invasive Thysanoptera in California………...………………………………..1 Invasive Species and the Urban Environment…………………………………….2 Thysanoptera………………………………………………………………………8 Myoporum Thrips as a Pest……………………………………………………...11 Integrated Pest Management……………………………………………………..13 Dissertation Objectives…………………………………………………………..19 References Cited…………………………………………………………………20 Chapter 2. Predicting the Potential Invasive Range of Klambothrips myopori………...28 Introduction………………………………………………………………………29 Materials and Methods…………………………………………………………...33 Results……………………………………………………………………………38 Discussion………………………………………………………………………..41 References Cited…………………………………………………………………46 Chapter 3. Host Plant Preference and Performance of Klambothrips myopori (Thysanoptera) in Southern California…………………………………………………..74 Introduction………………………………………………………………………75 viii Materials and Methods…………………………………………………………...77 Results……………………………………………………………………………81 Discussion………………………………………………………………………..83 References Cited…………………………………………………………………87 Chapter 4. Identification of Klambothrips myopori Predator Complex………………..98 Introduction………………………………………………………………………99 Materials and Methods………………………………………………………….101 Results…………………………………………………………………………..107 Discussion………………………………………………………………………111 References Cited……………………………………………………………..…117 Chapter 5. General Conclusions……………………………………………………….141 References Cited………………………………………………………………..147 ix List of Tables Table 2.1 CLIMEX parameters values for Klambothrips myopori……………………..58 Table 2.2 Development time (days) (mean ± SEM) for immature stages of Klambothrips myopori………………………………………………………………………………..…59 Table 2.3 Estimated parameters (a and b), lower developmental threshold (°C), and thermal constant (K) from linear regression……………………………………………..60 Table 2.4 Parameter estimates (±SEM) for three nonlinear development rate models for Klambothrips myopori ……………………………………………………………..........61 Table 2.5 Summary of climate variables used in the Maxent model……………….......63 Table 3.1 Injury rating scale for K. myopori on M. laetum……………………………...89 Table 3.2 The mean number of days (±SE) for K. myopori to complete development at 25°C……………………………………………………………………………………...90 Table 3.3 Predators collected on Myoporum varieties from surveys between August 2015 through July 2016 at the SCREC………………………………………………………...91 Table 3.4 Predators collected on Myoporum varieties from surveys between August 2015 through July 2016 at the San Jacinto site………………………………………………...92 Table 4.1 Mean annual weather variables for three collection sites from Arguez et al. (2012)………………………………………………………………………...................121 Table 4.2 Potential predators of K. myopori collected on Myoporum laetum from surveys between June 2014 through May 2015…………………………………………………122 Table 4.3 Functional response of Orius insidiosus based on logistic regression estimate using Ne/No………………………………………………………………………..........125 Table 4.4 Estimated type II functional response parameters ± SE (95% confidence interval) for O. insidiosus feeding on different life stages of K. myopori……………...126 x Table 4.5 Functional response of Chrysoperla rufilabris based on logistic regression estimate using Ne/No……………………………………………………………………127 Table 4.6 Estimated functional response parameters ± SE (95% confidence interval) for C. rufilabris feeding on different life stages of K. myopori……………………………….128 xi List of Figures Figure 2.1 Distribution map of Myoporum. Taken from Discover Life 2014…………..64 Figure 2.2 Linear and three nonlinear functions fit to the data of developmental rates (1/days) of K. myopori……………………………………………………………..…….65 Figure 2.3 Map of predicted environmental suitability for K. myopori from CLIMEX for California………………………………………………………………………………...66 Figure 2.4 Map of predicted environmental suitability for K. myopori from CLIMEX for Hawaii……………………………………………………………………………………67 Figure 2.5 Map of predicted environmental suitability for K. myopori from CLIMEX for North America…………………………………………………………………………...68 Figure 2.6 Map of predicted environmental suitability for K. myopori from CLIMEX for Australia…………………………..……………………………………………………..69