STUDIES ON THE CLOVER ROOT BORER, HYMSTINUS OBSCURUS (KARSHAM) DISSERTATION Presented in Partial FuliiIlment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By KENNETH PAUL FRUESS, B.S., M.S. The Ohio State University 1957 Approved by: Adviser Department of Zoology and Entomology ACKSQttffiCMST^TS ?he research for this dissertation was done a t the Ohio Agricultural Experiment Station, W o o s t e r , Ohio, w h e r e I was employed as a Research Assistant from June, 1 9 5 ^ j to March, 1957. I am grateful for the facilities offered t > y this instituition and for the aid of .many members of the stafr d u r i n g my s t a y there. I wish especially to thank Dr, C » -ft. Weaver, wino encouraged this research and offered many h e l p f u H suggestions and criticisms. I also wish to thank Dr, Ralph H . Davidson, w h o acted as n y adviser at The Ohio State University a n d directed m y work there. Valuable information was supplied t y the f ol lowing persons a m is gratefully acknowledged: Mr. A, Dickason, Oregon State College; Dr, Ray T, Everly, Purdue University,* Dr. G-eorge G. Gyrisco and Mr, Carlton S, Koehler, C o r n e l l University; and Dr, A. K. Woodside, Virginia Agricultural Experiment Sts/tion. ii TABLE OF CON TENTS Page INTRODUCTION ........ 1 PART I. THE CLOVER ROOT BORER ................... 2 Taxonomic Position .................... 2 Distribution................................ 3 Spread in Ohio .......................... 6 Economic Importance ...................... 7 BIOLOGY AND ECOLOGY.............................. 13 Introduction ............................. 13 The A d u l t .................................. 13 Fall Behavior.......................... IS Early Spring Behavior ....................* 16 Flight ........ 17 Traps for Determining Flight ......... 1? Sexual Development ........ 19 Relation of Temperature to Flight ....... 20 A Temperature Summation Method of Predicting F l i g h t ......................... 21 Mating ...... ....................... 2$ Sex Ra t i o ........ 26 Secondary Sexual Characteristics 27 Flight Range ............ 28 exposition .... ............. ........ .. 28 Reproductive Potential........ .......... 29 iii Page Longevity .......................... 30 Natural-Snemi.es .......... 31 Effect of Moisture on Adults ... 32 Effect of Host Condition on Ovipositaon ... 34 The Egg .......... 36 Description .................... 36 Incubation Period ...................... 36 Natural Enemies ......................... 37 The L a r v a ................. 37 Description............... 37 Rate of Development.............. 33 Effect of Plant Condition on Development .... 39 Number of Instars .............. 1*0 Rearing Methods........ 4l Natural Enemies...... bh The Pupa ......... itU Description............................ 144- Rate of Development............ 45 Natural Enemies....... 46 SEASONAL HISTORY.............. 46 NUMBER OF GENERATIONS............................ $0 HOST PLANTS................... .................. 51 VARIETAL RESISTANCE OF CLOVER TO ROOT BORER ............. 54 iv Page DAMAGE ............. 57 Effect of Moisture on Damage ........... 58 ESTIMATION OF YIELD REDUCTION ..................... 6U CONTROL ...................................... 71 Introduction ........................ 71 Control Experiments ............ 73 Residual Action of Soil Insecticides .............. 76 PART H. EVALUATION OF CLOVER ROOT BORER POPULATIONS 78 INTRODUCTION............. 78 DISTRIBUTION OF ROOT BORER COUNTS.................. 79 Distribution of Individual Root Counts......... 79 Introduction ................ 79 Negative Binomial Distribution........ 80 Neyssan’s Contagious Distributions ...... 83 Fitting Neyman1 s Distribution ....... 83 Fitting Neyman1 s Distribution for n ■ 0 ..... 85 Fitting Neyman's Distribution for n ^ co .... 87 Double Poisson...... 87 SuEssary of Frequency Distributions ... 89 Distribution of Sample Mean.s ........... 90 Five Root Samples ..... 91 Ten Root Samples .... 91 Conclusion.............. 91 v Page TRANSFORMATIONS....................... .......... 92 Introduction.......... *.......... 92 Transforming Individual Root Counts ...... 9U Estimation of q ................... 102 Transformation of Multiple Root Counts .......... 102 Conclusion 10 8 VALUE OF TRANSFORMATIONS.......................... 108 Effect on Additivity ................. Ill Homogeneity of Variance ..................... 116 Application of Inverse Hyperbolic Sine Transforma­ tion .................................. 117 Other Tests ........ 120 t - t e s t ............... 121 EFFICIENCY OF TRANSFORMATION.......... ............ 123 EFFICIENCY OF SAMPLING DESIGNS .......... 128 1955 Sampling Experiment....... ............... 128 1956 Sampling Study .......................... 131 SEQUENTIAL SAMPLING FOR CLOVER ROOT BORER SURVEYS 135 Introduction ..... 135 Homogeneity of k ............ .. .............. lUo Calculation of Acceptance and Rejection Lines .... i M Application of Sequential P l a n ... .......... 151 ESTIMATING BORERS PER ROOT FROM PER CENT INFESTED ROOTS 152 SUMMARY AND CONCLUSIONS............. ..... ......... 15U Part I ............... ...................... 1 vi Page Part II ........... l£6 APPENDIX A. MATHEMATICAL DISTRIBUTION OP CLOVER ROOT BORER COUNTS.......................................... 158 LITERATURE CITH)........................ 172 vii LIST OF TABLES Number Page 1 Direction of flight of root borers ........... ,. 18 2 Effectiveness of vertical vs. horizontal traps ... 20 3 Comparison of methods for predicting spring flight 23 h Sex ratio ................. 26 5 Estimation of offspring per f e male ............. 31 6 Effect of rainfall on borer populations .... 3b 7 Populations and development in early vs. late cut fields .......... ....................... 35 8 Number and development in dead vs. living roots .. 1*0 9 Composition of artificial medium ............... k3 10 Seasonal development of borer, 195U-1956....... JU7 11 Extreme dates for various stages in life history . 50 12 Host plants for root borer .......... 53 13 Borer populations in five varieties of red clover . 55 lb Summary of 1956 variety trial at Wooster ..... 56 15 Clover yields under different levels of rainfall and root borers .............. 60 16 ---- . .Analysis of variance for Table 15 ............ 6l 17 Clover yields under different levels of rainfall and root borers, 1956 ............... 62 18 Analysis of variance for Table 17 .............. 63 19 Summary of yield reductions by root borer under different levels of rainfall...... 63 viii Number Page 20 Test for curvilinear! ty of regression of weight on crown diameter....... 60 21 Cojsputation of correlation coefficients among four measurements on red clover p lants.... 6? 22 Calculation of Gauss multipliers for data in Table 21 ........................... 65 23 Test of significance of four variable regression . 69 2k Summary of yield reductions by root borer in three fields ....................... 71 20 Root borer control by surface applications of al- drin at time of band seeding ........ 7li 26 Control of root borer by granules ............. 76 27 Borers in plots treated in 1902 ............... 77 28 Method of fitting negative binomial........... 82 29 Calculation of recurrent coefficients for Neyman's distribution ....................... 85 30 Summary of frequency distributions fitted to Vir­ ginia counts. Treated plots, experiment 1. 190k .............................. 86 31 Distribution of borers in 0 root samples ....... 92 32 Distribution of borers in 10 root samples 93 33 Values of inverse hyperbolic sine transformation . 99 3U Test for non-additivity, 1905 moisture experiment, untransformed ...................... 112 30 Test for non-additivity, 1900 moisture experiment, transformed ......... 113 36 Test for non-additivity, 1906 moisture experiment, untransformed ....... 113 37. Test for non-additivity, 1906 moisture experiment, transformed ............... U u ix Humber Page 38 Test for non-additivity, Frye 909 experiment 1, untransformed .... ..... ......... Ill* 39 Test for non-additivity, Frye 909 experiment 1, transformed ...... ................. XI5 UO Test for non-additivity, Frye 909 experiment 2, untransformed......................... 115 ill Test for non-additivity, Frye 909 experiment 2, transformed ....... ................ 115 1x2 Test for homogeneity cf variance, 19$$ moisture experiment, untransformed ........ 116 U3 Comparison of homogeneity of variance for trans­ formed and untransformed data ............ 117 hh Test for non-additivity, 19$$ moisture experiment, individual roots transformed ...... 118 hS Test for non-additivity, 1956 moisture experiment, individual roots transformed............. 119 U6 Test for non-additivity, Frye 909 experiment 1, individual roots transformed ........ 119 U? Test for non-additivity, Frye 909 experiment 2, individual roots transformed ...... 120 US Analysis of aldrin band application test, un­ transformed ............................ 121 ii9 Analysis of aldrin band application test, trans­ formed ............... ................ 121 50 Analysis of Grafton test, transformed ............ 122 51 Comparison of t values for untransformed vs. transformed counts .............. ....... 122 >2 Jhimber of one root samples to discover specific differences, untransformed ........... 12i| 53 Number of one root samples to discover specific differences, transformed ......... 125 x Number Page 5U Number of 10 root samples to discover specific differences,