EHA ŠVILPONIS FACTORS INFLUENCING THE DISTRIBUTION AND OVERWINTERING SURVIVAL THE OF POTATO ROT NEMATODE VIIS VIIMAST KAITSMIST MARIS HORDO APPLICATION OF DENDROCLIMATOLOGICAL METHODS FOR FOREST GROWTH MODELLING. DENDROKLIMATOLOOGILISTE MEETODITE KASUTAMINE PUISTU KASVUKÄIGU MODELLEERIMISEL. Prof. Andres Kiviste, dr. Helena Henttonen, dr. Samuli Helama 27. aprill 2011 MARIT KOMENDANT ANTENNAL CONTACT CHEMORECEPTION IN GROUND BEETLES (COLEOPTERA: CARABIDAE). FACTORS INFLUENCING THE DISTRIBUTION JOOKSIKLASTE (COLEOPTERA: CARABIDAE) ANTENNAALNE AND OVERWINTERING SURVIVAL KEMORETSEPTSIOON. Vanemteadur Enno Merivee, prof. Anne Luik OF THE POTATO ROT NEMATODE 6. mai 2011 (Ditylenchus destructor Thorne 1945) VAHUR PÕDER KARTULIINGERJA COMPATIBILITY OF ENERGY CONSUMPTION WITH THE CAPACITY (Ditylenchus destructor Thorne 1945) OF WIND GENERATORS. LEVIKUT JA TALVIST ELLUJÄÄMIST MÕJUTAVAD ENERGIA TARBIMISE SOBIVUS TUULEGENERAATORITE VÕIMSUSEGA. Prof. Andres Annuk FAKTORID 21. juuni 2011 MERIKE LILLENBERG RESIDUES OF SOME PHARMACEUTICALS IN SEWAGE SLUDGE IN ESTONIA, THEIR STABILITY IN THE ENVIRONMENT AND ACCUMULATION INTO FOOD EHA ŠVILPONIS PLANTS VIA FERTILIZING. MÕNEDE RAVIMIJÄÄKIDE SISALDUS EESTI REOVEESETTES, NENDE STABIILSUS KESKKONNAS JA AKUMULEERUMINE A Thesis KOMPOSTVÄETISEST TOIDUTAIMEDESSE. Prof. Lembit Nei, prof. Kalev Sepp for applying for the degree of Doctor of Philosophy 16. september 2011 in Agricultural Sciences in Plant Protection MARGE MALBE THE ROLE OF SELENIUM IN UDDER HEALTH OF DAIRY COWS. SELEENI TOIME LÜPSILEHMADE UDARA TERVISELE Väitekiri Prof. emer. Hannu Saloniemi, dots. Andres Aland 7. oktoober 2011 Filosoofiadoktori kraadi taotlemiseks Põllumajanduse õppekava taimekaitse erialal Tartu 2011 EESTI MAAÜLIKOOL ESTONIAN UNIVERSITY OF LIFE SCIENCES FACTORS INFLUENCING THE DISTRIBUTION AND OVERWINTERING SURVIVAL OF THE POTATO ROT NEMATODE (Ditylenchus destructor Thorne 1945) KARTULIINGERJA (Ditylenchus destructor Thorne 1945) LEVIKUT JA TALVIST ELLUJÄÄMIST MÕJUTAVAD FAKTORID EHA ŠVILPONIS A Thesis for applying for the degree of Doctor of Philosophy in Agricultural Sciences in Plant Protection Väitekiri Filosoofiadoktori kraadi taotlemiseks Põllumajanduse õppekava taimekaitse erialal Tartu 2011 Institute of Agricultural and Environmental Sciences Estonian University of Life Sciences According to the verdict No 88 of 2. November, 2011 the Doctoral Committee of Agricultural and Natural Sciences of the Estonian University of Life Sciences has accepted the thesis for the defence of the degree of Doctor of Philosophy in Agricultural Sciences in Plant Protection. Opponent: Dr. Christer Magnusson, BIOFORSK Norwegian Institute for Agricultural and Environmental Research Department of plant health and plant protection Supervisor: Prof. Anne Luik Institute of Agricultural and Environmental Sciences Estonian University of Life Sciences † Prof. Emer. Eino Krall University of Tartu Defence of the thesis: Estonian University of Life Sciences, room 1A5, Kreutzwaldi 5, Tartu On 09. December 2011, at 11:00. The English language was edited by Ingrid H. Williams and the Estonian by Signe Siim. Publication of this thesis is supported by the Estonian University of Life Sciences and by the Doctoral School of Earth Sciences and Ecology created under the auspices of European Social Fund. © Eha Švilponis, 2011 ISBN 978-9949-484-12-6 CONTENTS LIST OF ORIGINAL PUBLICATIONS ................................... 7 ABBREVIATIONS .................................................................... 8 1. INTRODUCTION ................................................................... 9 2. REVIEW OF THE LITERATURE .......................................... 12 2.1. Dry rot of potatoes and an invertebrate pathogen – Potato rot nematode Ditylenchus destructor as the causal agent .... 12 2.1.1. Invasion and spread of D. destructor ....................... 13 2.1.2. Significance of D. destructor in Estonia ................... 18 2.2. Factors affecting invertebrate overwintering ..................... 20 2.2.1. Negative temperature extremes in pest control ....... 20 2.2.2. Cold tolerance in nematodes .................................. 21 2.2.3. Overwintering strategies in invertebrates ................ 23 3. AIMS OF THE STUDY .......................................................... 26 4. MATERIALS AND METHODS ............................................. 27 4.1. Data survey: The effect of trade on distribution of Ditylenchus destructor ........................................................ 27 4.2. Laboratory experiments: The effect of media and cold on invertebrate survival ......................................................... 28 4.2.1. Subjects .................................................................. 28 4.2.2. Laboratory equipment and measurements .............. 28 4.2.3. Data acquisition and statistics ................................ 31 4.3. Field experiment: The effect of snow treatments on soil temperature ...................................................................... 32 4.3.1. Experimental setup ................................................. 32 4.3.2. Measurements and statistics ................................... 33 5. RESULTS ................................................................................. 34 5.1. Ditylenchus destructor in international trade ...................... 34 5.2. Media and cold as factors influencing invertebrate survival 36 5.2.1. Optimization of research methods .......................... 36 5.2.2. The effect of media ................................................ 37 5.2.3. The effect of subzero temperatures ......................... 38 5.3. Snow treatment for reduction of soil temperatures ........... 41 6. DISCUSSION ......................................................................... 43 6.1. The effect of trade on distribution of Ditylenchus destructor 43 6.2. Application of research methods for nematological studies 46 6.3. Environmental conditions influencing the survival of Ditylenchus destructor ........................................................ 47 6.3.1. The effect of media ................................................ 47 6.3.2. The effect of subzero temperatures ......................... 47 6.3.3 The effect of snow treatments on soil temperature and their suitability for pest control ................................. 50 7. CONCLUSIONS .................................................................... 53 REFERENCES ........................................................................ 55 SUMMARY IN ESTONIAN ................................................... 68 ACKNOWLEDGEMENTS .................................................... 71 PUBLICATIONS .................................................................... 73 CURRICULUM VITAE ........................................................ 131 ELULOOKIRJELDUS .......................................................... 133 LIST OF PUBLICATIONS ................................................... 135 LIST OF ORIGINAL PUBLICATIONS The current thesis is a review of the following papers which are referred to by Roma n numerals in the text. The papers are reproduced by kind permission of the following journals: Zemdirbyste-Agriculture (II), Ento- mologia Experimentalis et Applicata (III, IV), Nematology (V). I Švilponis, E. Impact of trade on distribution of potato rot nema- tode (Ditylenchus destructor) and other plant nematodes. Agronomy Research (submitted). II Švilponis, E.; Luik, A.; Krall, E. (2008) Plant parasitic ditylenchids in Estonia. Zemdirbyste-Agriculture, 95(3), 186 - 193. III Hiiesaar, K.; Williams, I.; Luik, A.; Metspalu, L.; Muljar, R.; Jõgar, K.; Karise, R.; Mänd, M.; Svilponis, E.; Ploomi, A. (2009) Factors affecting cold hardiness in the small striped flea beetle, Phyllotreta undulata. Entomologia Experimentalis et Applicata, 131: 278–285. IV Hiiesaar, K.; Williams, I.H.; Mänd, M.; Luik, A.; Jõgar, K.; Met- spalu, L.; Švilponis, E.; Ploomi, A.; Kivimägi, I. (2011) Supercool- ing ability and cold hardiness of the pollen beetle. Entomologia Experimentalis et Applicata, 138(2), 117 - 127. V Švilponis, E.; Hiiesaar, K.; Kaart, T.; Metspalu, L.; Mänd, M.; Ploomi, A.; Williams, I.H.; Luik, A. (2011) Low temperature sur- vival of the potato rot nematode Ditylenchus destructor Thorne (Tylenchida: Anguinidae) post-eclosion stages. Nematology, 13(8), 967-973. VI Švilponis, E.; Hiiesaar, K.; Metspalu, L., Mänd, M., Jõgar, K.; Veromann, E., Luik, A. (2011) Snow manipulation as an alternative nematode control strategy. Zemdirbyste-Agriculture (submitted). Table 1. Author’s contribution to each article (%). I II III IV V VI Idea and design 85 80 10 10 75 95 Data collection 100 95 5 5 100 80 Data analysis, statistics 100 100 5 5 45 95 Writing 95 95 5 5 85 95 7 ABBREVIATIONS LLT Lower Lethal Temperature (temperature at which 100% of the population is killed) LT50 Lethal Temperature to 50% mortality (temperature at which 50% of the population is killed) LT90 Lethal Temperature to 90% mortality (temperature at which 90% if the population is killed) SCP Supercooling Point EPPO European and Mediterranean Plant Protection Organization 8 1. INTRODUCTION Potato rot nematode, Ditylenchus destructor Thorne 1945 was a serious pest of potato in Europe in 1950 – 1970s. During that period, it was evaluated to cause greater crop losses than potato cyst nematode, Glo- bodera rostochiensis in Estonia (Krall, 1974). The problem in Estonia was eventually alleviated by using in-vitro cultured basic material, informing state farms’ agronomists