Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1976 Synecology of edaphic Arthropoda in Iowa agroecosystems Milgar Camargos Loureiro Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Entomology Commons Recommended Citation Loureiro, Milgar Camargos, "Synecology of edaphic Arthropoda in Iowa agroecosystems " (1976). Retrospective Theses and Dissertations. 5659. https://lib.dr.iastate.edu/rtd/5659 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. INFORMATION TO USERS This material was produced from a microfilm copy of the original document. 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Xerox University Microfilms 300 North Zeeb Road Ann Arbor, Michigan 48106 76-18,283 LOUREIRO, Milgar Camargos, 1931- SYNECOLOGY OF EDAPHIC ARTHROPODA IN IOWA AGROECOSYSTEMS. Iowa State University, Ph.D., 1976 Entomology Xerox University Microfilms, Ann Arbor, Michigan 48io6 gynecology of edaphic Arthropoda in Iowa agroecosystems by Milgar Camargos Loureiro A Dissertation Submitted to the Graduate Faculty in Partial Fulfillment of The Requirements for the Degree of DOCTOR OF PHILOSOPHY Maj or ; Entomology Approved: Signature was redacted for privacy. Chargf"5r^HS}or Work Signature was redacted for privacy. For the Major Departmen Signature was redacted for privacy. Iowa State University Ames, Iowa 1976 ii TABLE OF CONTENTS Page DEDICATION ix INTRODUCTION 1 LITERATURE REVIEW 4 The Soil Environment 4 Hydrogen-ion concentration 5 Temperature 8 Moisture 12 Texture 14 Agricultural practices 15 Pesticides 17 Tilled-Soil Fauna 20 Iowa situation 20 Analytical Methods 23 Ordination 23 MATERIALS AND METHODS 25 Sampling Program 25 Sample site and field history 25 Collection of samples: 1972 28 Collection of samples: 1973-1974 29 Arthropoda Extraction Method 33 Identification and Storage 36 iii Page Ordination 37 RESULTS AND DISCUSSION 40 Arthropoda Extraction Method 40 Sampling Program 1972 41 Microarthropod fauna 41 The soil environment 1972 54 Hydrogen-ion concentration 54 Temperature 55 Moisture 57 CO Texture Agricultural practices 59 Sampling Program 1973-1974 60 Microarthropod fauna 60 The soil environment 1973-1974 87 Hydrogen-ion concentration 87 Temperature 91 Moisture 91 Pore space 95 Texture 96 Agricultural practices 97 Pesticides 97 Ordination 99 Ordination of agroecosystems: 1972 100 Ordination of agroecosystems: 1973 103 Ordination of agroecosystems; 1974 107 SUMMARY AND CONCLUSION LITERATURE CITED ACKNOWLEDGMENTS V LIST OF TABLES Page Table 1. Total prominence values of edaphic Arthropoda in 5 soybean agroecosystems. Iowa, June to August 1972 42 2 Table 2. Population density in hundreds/m (T), percentage I, average (X), and standard error (SE) of edaphic Arthropoda in 5 soybean agroecosystems. Iowa, June to August 1972 51 Table 3. Measurements of abiotic soil components in 5 soy­ bean agroecosystems. Iowa, June to August 1972 56 Table 4 Total prominence values of edaphic Arthropoda in 4 continuous corn, 4 continuous soybean, and 4 oats-soybean-corn rotation agroecosystems. Ames, June to October 1973 61 Table 5. Total prominence values of edaphic Arthropoda in 4 continuous corn, 4 continuous soybean, and 4 oats-soybean-corn rotation agroecosystems. Ames, June to October 1974 70 Table 6. Total number of families (F) and genera (G) of edaphic Arthropoda collected in Iowa agro­ ecosystems 1972-1974 79 2 Table 7. Population density (hundreds/m ) of edaphic Arthropoda in 4 continuous corn, 4 continuous soybean, and 4 oats-soybean-corn rotation VI Page agroecosystems. Ames, June to October 1973 81 2 Table 8. Population density (hundreds/m ) of edaphic Arthropoda in 4 continuous corn, 4 continuous soybean, and 4 oats-soybean-corn rotation agroecosystems. Ames, June to October 1974 82 Table 9. Percentage of the total PV of the most prominent edaphic Arthropoda in 4 continuous corn, 4 continuous soybean, and 4 oats-soybean-corn rotation agroecosystems. Ames, June to October 1973 85 Table 10. Percentage of the total PV of the most prominent edaphic Arthropoda in 4 continous corn, 4 continuous soybean, and 4 oats-soybean-corn rotation agroecosystems. Ames, June to October 1974 86 Table 11. Measurements of abiotic soil components in 4 continuous corn agroecosystems. Ames, June to October 1973 88 Table 12. Measurements of abiotic soil components in 4 continuous soybean agroecosystems. Ames, June to October 1973 89 Table 13. Measurements of abiotic soil components in 4 oats-soybean-corn rotation agroecosystems. Ames, June to October 1973 90 Table 14. Measurements of abiotic soil components in 4 vii Page continuous corn agroecosystems. Ames, June to October 1974 92 Table 15. Measurements of abiotic soil components in 4 continuous soybean agroecosystems. Ames, June to October 1974 93 Table 16. Measurements of abiotic soil components in 4 oats-soybean-corn rotation agroecosystems. Ames, June to October 1974 94 Table 17. Duncan's Multiple Range Test of averages of soil moisture content for 4 continuous corn (1973) and 4 continuous soybean (1974) agro­ ecosystems in Ames 95 Table 18. Duncan's Multiple Range Test of averages of total percentage of soil pore space for 4 continuous corn agroecosystems. Ames, 1974 96 Table 19. Ratio of decline between 1973 and 1974 Mesostigmata PV in 4 continuous corn, 4 continuous soybean, and oats-soybean-corn rotation ajrc^cosystems in Ames 98 viii LIST OF FIGURES Pa Page Figure 1. Iowa cities nearest sampling sites 26 Figure 2. Detachment of the corer from the soil sampler 31 Figure 3. Soil sample in the corer being inverted intact on the sieve 31 Figure 4. Introduction of the corer into the soil by standing on the ends of the rods 32 Figure 5. Battery of modified Tullgren funnels 34 Figure 6. Ordination of 5 soybean agroecosystems: 1972 102 Figure 7. Ordination of 4 continuous corn, 4 continuous soybean, and 4 oats-soybean-corn rotation agroecosystems: 1973 104 Figure 8. Ordination of 4 continuous corn, 4 continuous soybean, and 4 oats-soybean-corn rotation agroecosystems: 1974 108 ix DEDICATION I would like to dedicate this thesis to my wife Maria Martha P. Loureiro, whose love, understanding, encouragement of iny work greatly aided in the completion of this research. 1 INTRODUCTION Given the widest interpretation, the group "edaphic Arthropoda" could include almost all terrestrial arthropods. In fact, 95% of all Insecta inhabit the soil at some time during their life cycle (Buckle, 1923), and insect species comprise approximately 80% of all animal species (Ross, 1965). Because these arthropods do not have equal degrees of association with the soil, it is difficult to determine what exactly constitutes a true edaphic arthropod. Thus, several criteria have been used in defining the various soil dwellers such as: body size, presence, habitat preference, and activity (Bachelier, 1968; Kevan, 1968; Kuhnelt, 1961; and Wallwork, 1970). Another criterion is based on the soil definition. The crust of the earth is derived primarily from minerals from the magma, which contain all the chemical elements obtained by the plants, except nitro­ gen. Soil nitrogen is stored in organic matter, the organic matter resulting from fragmentation of litter and cadavers. Thompson (1957) defines soils as "mixtures of mineral and organic matter that are capable of supporting plant life". Organic matter is considered herein as all material which is in the process of decomposition.