Population Dynamics of Oribatid Mites (Acari: Oribatida) on Horse Pastures of North Central Florida
Total Page:16
File Type:pdf, Size:1020Kb
POPULATION DYNAMICS OF ORIBATID MITES (ACARI: ORIBATIDA) ON HORSE PASTURES OF NORTH CENTRAL FLORIDA By MERIJO EILEEN JORDAN A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE UNIVERSITY OF FLORIDA 2001 ACKNOWLEDGMENTS I would like to thank my committee members, Charles Courtney, Jerry Butler, Joe DiPietro, and Ellis Greiner, for all of their helpful advice and support. Qi-Yun Zeng is an amazing person. She helped in many aspects of data collection and she turned out to be a brilliant mite sorter. Without Roy Norton's guidance and oribatid expertise, this project could have never gotten off the ground. He taught me useful techniques for handling and identifying oribatid mites and he confirmed my generic identifications and often identified the mites to species. I am deeply indebted to all of these wonderful people who are so dedicated to science and teaching. They are wonderful people to work for and with. I would also like to thank my family, Patrick Meeus, and Don and Linda Jordan, for all of the encouragement to finish what I had started. For their undying support, understanding, and patience I am forever grateful. Finally, I would like to acknowledge that American Association of Equine Practitioners Foundation, Inc., partially funded this research with a research scholarship. ii TABLE OF CONTENTS page ACKNOWLEDGMENTS................................................................................................... ii LIST OF TABLES ...............................................................................................................v LIST OF FIGURES............................................................................................................ vi LITERATURE REVIEW.....................................................................................................1 Anoplocephala perfoliata ............................................................................................... 1 Morphology................................................................................................................. 2 Life Cycle.................................................................................................................... 6 Epidemiology............................................................................................................ 10 Pathology................................................................................................................... 13 Clinical Syndrome ..................................................................................................... 16 Diagnosis................................................................................................................... 18 Treatment and Prevention......................................................................................... 22 Oribatid Mites ............................................................................................................... 25 Morphology............................................................................................................... 25 Basic Biology............................................................................................................ 27 Factors that influence oribatid mite distribution................................................... 27 Feeding habits ....................................................................................................... 29 Reproduction............................................................................................................. 31 Life Cycle.................................................................................................................. 32 Oribatid Mites as Anoplocephaline Intermediate Hosts ........................................... 34 Determining Factors for an Effective Intermediate Host...................................... 36 Known Intermediate Hosts of A. perfoliata.......................................................... 37 Effects on the Intermediate Host........................................................................... 38 Variations in the Oribatid Mite Populations ............................................................. 39 Seasonal Variations in Oribatid Mite Populations ................................................ 40 Daily Variations in Oribatid Mite Distribution..................................................... 42 SEASONAL AVAILABLITY OF ORIBATID MITES....................................................44 Objective....................................................................................................................... 44 Hypothesis..................................................................................................................... 44 Materials and Methods.................................................................................................. 45 Study Sites................................................................................................................. 45 iii Soil Sample Collection.............................................................................................. 48 Mite Extraction.......................................................................................................... 49 Taxonomic Identification.......................................................................................... 50 Tapeworm Infection in Horses.................................................................................. 52 Weather Data and Soil-Water Budgets ..................................................................... 53 Calculation of Population Distribution in Study Pastures ........................................ 55 Culturing Oribatid Mites........................................................................................... 56 Results ........................................................................................................................... 60 Oribatid Mites ........................................................................................................... 60 Fecal Analysis........................................................................................................... 63 Weather Data and Soil-Water Budgets ..................................................................... 63 Population Distribution in Study Pastures ................................................................ 64 Oribatid Mite Cultures .............................................................................................. 66 Discussion..................................................................................................................... 67 CONCLUSIONS................................................................................................................92 LIST OF REFERENCES ...................................................................................................93 BIOGRAPHICAL SKETCH ...........................................................................................106 iv LIST OF TABLES Table page 1. The mite taxa............................................................................................................. 61 2. Percent dominance by mite species at the Horse Research Center in 1999.............. 80 3. Percent dominance by mite species at the Horse Research Center in 2000.............. 81 4. Percent dominance by mite species at the Horse Teaching Unit in 1999. ................ 82 5. Percent dominance by mite species at the Horse Teaching Unit in 2000. ................ 83 6. Annual dominance and frequency for mites from the HRC in 1999. ....................... 84 7. Annual dominance and frequency for mites from the HRC in 2000. ....................... 85 8. Annual dominance and frequency for mites from the HTU in 1999. ....................... 86 9. Annual dominance and frequency for mites from the HTU in 2000. ....................... 87 10. Index of Aggregation and R2 for each mite species.................................................. 88 11. Results of mite dissections 4 weeks post-exposure to A. perfoliata eggs................. 89 12. Results of mite dissections 5 to 20 weeks post-exposure to A. perfoliata eggs...... 89 13. Oribatid Mites Collected from Study Pastures (exposed mites offered A. perfoliata eggs in laboratory on 3/23/00). ................................................................................. 91 v LIST OF FIGURES Figure page 1. Adults of Anoplocephala perfoliata. .......................................................................... 5 2. Egg of Anoplocephala perfoliata................................................................................ 5 3. Layout of Horse Teaching Unit. Asterisk indicates location of the study pasture... 46 4. Layout of Horse Research Center. Asterisk indicates the location of the study pasture. ...................................................................................................................... 47 5. Berlese funnel apparatus. .......................................................................................... 51 6. Selected oribatid mite genera (collected during the study). a) Rostrozetes ovulum (Berlese); b) Ceratozetes n sp.; c) Epilohmannia minuta (Ewing); d) Zygoribatula sp. nr floridana (Fritz); e) Galumna minuta (Ewing). .............................................. 62 7. Monthly precipitation Gainesville. ........................................................................... 75