Life History and Natural Enemies of Parthenolecanium Spp. in Four Southeastern States Ernesto Robayo Camacho Clemson University, Ernesto [email protected]
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Clemson University TigerPrints All Dissertations Dissertations 5-2015 Life History and Natural Enemies of Parthenolecanium spp. in Four Southeastern States Ernesto Robayo Camacho Clemson University, [email protected] Follow this and additional works at: https://tigerprints.clemson.edu/all_dissertations Part of the Biology Commons, Ecology and Evolutionary Biology Commons, and the Entomology Commons Recommended Citation Robayo Camacho, Ernesto, "Life History and Natural Enemies of Parthenolecanium spp. in Four Southeastern States" (2015). All Dissertations. 1525. https://tigerprints.clemson.edu/all_dissertations/1525 This Dissertation is brought to you for free and open access by the Dissertations at TigerPrints. It has been accepted for inclusion in All Dissertations by an authorized administrator of TigerPrints. For more information, please contact [email protected]. LIFE HISTORY AND NATURAL ENEMIES OF PARTHENOLECANIUM SPP. IN FOUR SOUTHEASTERN STATES A Dissertation Presented to the Graduate School of Clemson University In Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy Entomology by Ernesto Robayo Camacho May 2015 Accepted by: Juang-Horng Chong, Committee Co-Chair Robert G. Bellinger, Committee Co-Chair William C. Bridges, Jr. Alfred G. Wheeler, Jr. i ABSTRACT Soft scales (Hemiptera: Coccidae) are some of the most prevalent and difficult to control arthropod pests in urban landscapes of the southern United States. European fruit lecanium, Parthenolecanium corni (Bouché), and oak lecanium, Parthenolecanium quercifex (Fitch), are commonly found in mixed populations as pests of oak trees (Quercus spp.) in the region. The phenology and natural enemies of the two species are poorly understood, which in turn hinders pest managers’ ability to develop an integrated management program against these species. This research project aims to fill the information gaps concerning the life history and natural enemies of P. corni and P. quercifex . The first study sought to better understand the life history of P. corni and P. quercifex in South Carolina, and to develop predictive models (based on degree-day and plant phenological indicators) for crawler emergence in Georgia, North Carolina, South Carolina and Virginia. The scale insects were found to be univoltine. Eggs hatched between mid-April and early June, second instars began to occur in October, and third instars and adults in mid-March to early April. Each parthenogenetic female produced 177 to 2,398 eggs. Fecundity was found to be proportional to weight of females (including eggs) and body length, width and height. Gross reproductive rate ( GRR ) was 695.98 ± 79.34 ♀/♀, net reproductive rate ( Rₒ) was 126.36 ± 19.03 ♀/♀, mean generation time ( TG) was 52.61 ± 0.05 weeks, intrinsic rate of increase (rm) was 0.04 ii ♀/♀/week, and finite rate of increase ( λ) was 1.04 times per week. Crawler emergence in Georgia, North Carolina, South Carolina and Virginia occurred when 229 degree-day units (DDC) had been accumulated with the simple-average method at a base temperature of 12.8 oC (55 oF), and at the first bloom of the southern magnolia, Magnolia grandiflora L. The second study documented and compared the species composition, seasonal activity and impacts of parasitoids and predators of Parthenolecanium spp. in Georgia, North Carolina, South Carolina and Virginia. Twenty-one parasitoid species and twelve predator species were found associated with the lecanium scales. Based on results of species diversity (Shannon, effective number of species, and Gini-Simpson indexes) and community similarity (Chao-Jaccard index) analyses, the parasitoid community in Georgia was different from those of the other states and the predator communities were different among the four states. Parasitism rates were 27-92% in South Carolina. Five main parasitoid species (Blastothrix sp. 1, Coccophagus lycimnia (Walker), Encyrtus sp. 1, Eunotus sp. and Pachyneuron sp.) emerged from adults and parasitism by these species reduced the fecundity of the scales. Coccophagus lycimnia was the only parasitoid species that emerged from immature scales. In the southeastern U.S. about 90% of the total abundance of the population is reached from late March to late August for parasitoids, and between late April and late October for predators. The third study evaluated the potential of Parthenolecanium spp.-infested willow oaks (Q. phellos L.) as banker plants for C. lycimnia that might attack other scale insect iii pest populations (such as the Florida wax scale, Ceroplastes floridensis Comstock) in the landscape. Parasitism rates by C. lycimnia were not significantly different between the exposed and unexposed hollies. The lack of significant difference was most likely due to failures in the experimental design and the time of exposure to parasitim. The potential of scale-infested willow oaks as banker plants in the landscape remains to be assessed. iv DEDICATION To my mother, for her unconditional love, support, and spiritual guidance throughout this unique learning experience. v ACKNOWLEDGMENTS I want to thank: • NIFA/USDA project/grant numbers 2010-34103-21144 (awarded to J.-H. Chong, S. Braman, S. Frank and P. Schultz), SC-1700351 (J.-H. Chong) and SC-1700473 (J.-H. Chong) for providing the funding for this research; • my advisor, Dr. Juang-Horng Chong, for his guidance, support, thoroughness, and patience throughout the development of this research project and dissertation; • my research collaborators at the University of Georgia (Dr. S. Kristine Braman), North Carolina State University (Dr. Steven D. Frank), and Virginia Polytechnic Institute and State University (Dr. Peter B. Schultz), and their assistants, for collecting data and samples; • my graduate committee - Dr. Alfred G. Wheeler, Dr. Robert G. Bellinger, and Dr. William C. Bridges Jr. - for their evaluation, assistance, understanding, and patience; • Shawn Chandler, Shannon Cook and Weber Mimms for their technical assistance; • Andrew Ernst at North Carolina State University for his help in identifying the parasitoids to the genus level; • Dr. Ian Stocks at the Florida Department of Agriculture and Consumer Services (FDACS), in Gainesville, Florida, for his help in the identification of crawlers of Parthenolecanium corni and P. quercifex , and confirmation of identity of the coleopterans collected in this research; vi • Dr. Greg Hodges at the FDACS for his help confirming the identification of P. corni and P. quercifex ; • Faculty and staff of the Department of Agricultural and Environmental Sciences and the Pee Dee Research and Education Center for their support and friendship. vii TABLE OF CONTENTS Page TITLE PAGE ........................................................................................................................ i ABSTRACT ......................................................................................................................... ii DEDICATION ..................................................................................................................... v ACKNOWLEDGMENTS ..................................................................................................... vi LIST OF TABLES ................................................................................................................. x LIST OF FIGURES ............................................................................................................. xii CHAPTER I. LITERATURE REVIEW AND INTRODUCTION SOFT SCALE INSECTS AND THEIR MANAGEMENT .................................... 1 Economic Importance .............................................................................. 1 Life Cycle and Biology .............................................................................. 8 Integrated Pest Management ................................................................ 15 Research Project .................................................................................... 32 References Cited .................................................................................... 34 II. LIFE HISTORY AND PHENOLOGY OF PARTHENOLECANIUM SPP. IN THE URBAN LANDSCAPES OF THE SOUTHEASTERN U.S. ......................................... 104 Introduction ......................................................................................... 104 Materials and Methods ........................................................................ 107 Results and Discussion ......................................................................... 113 References Cited .................................................................................. 127 viii Table of Contents (Continued) III. SPECIES COMPOSITION, SEASONAL ACTIVITY AND IMPACT OF PARASITOIDS AND PREDATORS OF PARTHENOLECANIUM SPP. (HEMIPTERA: COCCIDAE) IN THE SOUTHEASTERN U.S. ............................................. 144 Introduction ......................................................................................... 144 Materials and Methods ........................................................................ 147 Results .................................................................................................. 154 Discussion............................................................................................. 160 References Cited .................................................................................. 172 IV. ASSESMENT OF PARTHENOLECANIUM SPP.-INFESTED WILLOW OAKS AS POTENTIAL BANKER PLANTS OF COCCOPHAGUS LYCIMNIA IN THE