The spatio-temporal dynamics of epigaeic predators and insect pests in different oilseed rape management systems [Elektronische Ressource] / von Daniela Simone Felsmann

Daniela Felsmann

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The spatio-temporal dynamics of epigaeic predators and insect pests in different oilseed rape management systems Von der Fakultät für Lebenswissenschaften der Technischen Universität Carolo-Wilhelmina zu Braunschweig zur Erlangung des Grades einer Doktorin der Naturwissenschaften (Dr. rer. nat.) genehmigte Dissertation von Daniela Simone Felsmann aus Kiel 1. Referent: apl. Professor Dr. Stefan Schrader 2. Referent: Professor Dr. Otto Larink eingereicht am: 28.03.2007 mündliche Prüfung (Disputation) am: 04.10.2007 Druckjahr 2008 Teilergebnisse aus dieser Arbeit wurden mit Genehmigung der Fakultät für Lebenswissenschaften, vertreten durch den Mentor der Arbeit, in folgenden Beiträgen vorab veröffentlicht: Publikationen Felsmann, D.; Büchs, W. (2006): Epigäische Raubarthropoden in zwei unterschiedlichen Rapsanbausystemen. - Mitteilungen der Biologischen Bundesanstalt für Land- und Forstwirtschaft, 403, 90-101. Felsmann, D.; Büchs, W. (2006): Assessment of staphylinid beetle larvae from oilseed rape flower stands and their influence on pollen beetle larvae. – IOBC/wprs Bulletin, in press. Tagungsbeiträge Felsmann, D.; Büchs, W. (2004): Einfluss epigäischer Raubarthropoden auf Rapsschädlinge in zwei Rapsanbausystemen. - DGaaE-Nachrichten, 18 (3), 91. Felsmann, D.; Büchs, W.

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• Publié par: technische_universitat_carolo-wilhelmina_zu_braunschweig
• Publié le: 01 janvier 2008
• Nombre de lectures: 74
• Langue: Deutsch
• Poids de l'ouvrage: 7 Mo

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von aus

The spatio-temporal dynamics of epigaeic predators and insect pests in different oilseed rape management systems Von der Fakultät für Lebenswissenschaften der Technischen Universität Carolo-Wilhelmina zu Braunschweig zur Erlangung des Grades einer Doktorin der Naturwissenschaften (Dr. rer. nat.) genehmigte D i s s e r t a t i o n

Daniela Simone Felsmann Kiel

1. Referent: apl. Professor Dr. Stefan Schrader 2. Referent: Professor Dr. Otto Larink eingereicht am: 28.03.2007 mündliche Prüfung (Disputation) am: 04.10.2007 Druckjahr 2008

Teilergebnisse aus dieser Arbeit wurden mit Genehmigung der Fakultät für Lebenswissenschaften, vertreten durch den Mentor der Arbeit, in folgenden Beiträgen vorab veröffentlicht: Publikationen Felsmann, D.; Büchs, W. (2006): Epigäische Raubarthropoden in zwei unterschiedlichen Rapsanbausystemen. -Mitteilungen der Biologischen Bundesanstalt für Land- und Forstwirtschaft,403, 90-101. Felsmann, D.; Büchs, W. (2006): Assessment of staphylinid beetle larvae from oilseed rape flower stands and their influence on pollen beetle larvae. – IOBC/wprs Bulletin, in press. Tagungsbeiträge Felsmann, D.; Büchs, W. (2004): Einfluss epigäischer Raubarthropoden auf Rapsschädlinge in zwei Rapsanbausystemen. -DGaaE-Nachrichten,18 (3), 91. Felsmann, D.; Büchs, W. (2004): Vergleichende Untersuchungen von zwei Rapsanbausystemen hinsichtlich des Schädlingsbefalls und des Auftretens von epigäischen Prädatoren. - 54. Deutsche Pflanzenschutztagung in Hamburg, 20.-23. September.Mitteilungen der Biologischen Bundesanstalt für Land- und Forstwirtschaft 396, 278-279. Felsmann, D.; Büchs, W. (2005): Untersuchungen in zwei Rapsanbausystemen zum Auftreten von epigäischen Raubarthropoden und Rapsschädlingen. -Dresdner Entomologentagung, 21.-24. März, 220. Felsmann, D.; Büchs, W. (2005): Spatio-temporal relationships between epigaeic predators and insect pests in winter oilseed rape. -Verhandlungen der Gesellschaft für Ökologie 35, 164. Felsmann, D. & Büchs, W. (2006): The spatio-temporal within-field distribution of pest larvae and key predators in Germany and the predators' effect on the emergence of new pest generations. –International Symposium on Integrated Pest Management in Oilseed Rape, University of Göttingen, 3.-5. April. Felsmann, D., Schlein, O. & Büchs, W. (2006): Management-related web densities, predation rates and prey composition of spiders (Linyphiidae andTheridion impressum) in oilseed rape fields. –International Symposium on Integrated Pest Management in Oilseed Rape, University of Göttingen, 3.-5. April. Felsmann, D. & Büchs, W. (2006): Predation rates and assessment of staphylinid beetle larvae from oilseed rape flower stands and their role in the regulation of pollen beetle larvae. - International Symposium on Integrated Pest Management in Oilseed Rape, University of Göttingen, 3.-5. April.

The spatio-temporal dynamics of epigaeic predators and insect pests in different oilseed rape management systems

Daniela S. Felsmann

Thanks to Eva for the loan of her stable event, You-know-who for a number of unstable events, my family for being stable through all events.

The spatio-temporal dynamics of epigaeic predators and insect pests in different oilseed rape management systems

List of contents

Introduction ................................................................................................................ 1 1. Comparison of different winter oilseed rape management systems regarding the infestation of the crop with insect pests and the effects on the epigaeic predators -Introduction............................................................................................................ 6 -Material and methods............................................................................................ 7 - The oilseed rape management systems ..................................................... 7 - Experimental site....................................................................................... 7 - Experimental design.................................................................................. 9 - Plant dissections ...................................................................................... 11 - Analytical statistics ................................................................................. 13 - Descriptive statistics................................................................................ 13 -Results................................................................................................................... 15 Results of the plant dissections......................................................................... 15 - Plant architecture..................................................................................... 15 -Psylliodes chrysocephala........................................................................ 15 -Ceutorhynchus pallidactylusandC.napi............................................... 16 -Dasineura brassicaeandC.assimilis..................................................... 17 Pest numbers in the oilseed rape management systems ................................... 25 -D. brassicae............................................................................................. 25 -Meligethesspp......................................................................................... 26 -C. assimilis, C. pallidactylusandC. napi............................................... 27 Yield levels ....................................................................................................... 29 Activity density of the epigaeic predators in the different oilseed rape management systems ................................................................................ 30 - Ground beetles (Carabidae)..................................................................... 30 - Rove beetles (Staphylinidae)................................................................... 39 - Spiders (Araneae).................................................................................... 43 Activity density of the epigaeic predators in the autumn ................................. 44 Emergence of the epigaeic predators in the winter wheat following the different oilseed rape management systems ..................................................... 45 Temporal coincidence between pest larval dropping and the activity density of the epigaeic predators in the different oilseed rape management systems... 47 -D. brassicae............................................................................................. 47 -Meligethesspp......................................................................................... 48

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The spatio-temporal dynamics of epigaeic predators and insect pests in different oilseed rape management systems

-C. assimilis.............................................................................................. 49 Discussion.............................................................................................................. 53 Conclusions........................................................................................................... 60 Summary............................................................................................................... 61 References............................................................................................................. 62 Appendix............................................................................................................... 69

2. Assessment of the spatio-temporal within-field distribution of pest larvae and epigaeic predators in different oilseed rape management systems -Introduction.......................................................................................................... 70 -Material and methods.......................................................................................... 71 -Results................................................................................................................... 73 Temporal coincidence between pest larval dropping and the activity density of the epigaeic predators................................................................................... 73 -D. brassicae............................................................................................. 73 -Meligethesspp......................................................................................... 78 -C. assimilis.............................................................................................. 83 Spatial distribution of pest larvae and epigaeic predators ................................ 88 Spatial association between predators and prey ............................................... 94 - betweenD. brassicaeand the epigaeic predators ................................... 94 - betweenMeligethesspp.and the epigaeic predators............................... 97 - betweenC. assimilis..................................... 98and the epigaeic predators - Discussion............................................................................................................ 100 -Conclusions......................................................................................................... 104 -Summary............................................................................................................. 104 -References........................................................................................................... 105 -Appendix............................................................................................................. 109

3. Assessment of Staphylinidae larvae from oilseed rape flower stands and their role in regulation of pollen beetle (Meligethesspp.) larvae -Introduction........................................................................................................ 115 -Material and methods........................................................................................ 115 -Results................................................................................................................. 116 Number ofMeligetheslarvae and Staphylinidae larvae in the different spp. management systems ...................................................................................... 116 Phenology ofMeligethes spp. larvae and Staphylinidae larvae and their temporal coincidence in the different oilseed rape management systems ...... 118 Correlations between the occurrence ofMeligethesspp. larvae and Staphylinidae larvae ....................................................................................... 123 The hatching of the new Meligethes generation in the different oilseed rape management systems .............................................................................. 123 Spatial relationship betweenMeligethesspp. larvae and Staphylinidae larvae ....................................................................................... 126

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The spatio-temporal dynamics of epigaeic predators and insect pests in different oilseed rape management systems

-Discussion............................................................................................................ 131 -Conclusions......................................................................................................... 133 -Summary............................................................................................................. 133 -References........................................................................................................... 134 4. Management related web density of web spiders within the vegetation layer in different oilseed rape management systems -Introduction........................................................................................................ 137 -Material and methods........................................................................................ 137 -Results................................................................................................................. 138 The density of webs of Theridionimpressumin the different management systems ...................................................................................... 138 Temporal coincidence between the larval dropping and the emergence ofD.brassicaeand the web density ofT.impressum.................................... 139 Actual assessment of the web density of Linyphiid spiders ........................... 144 Temporal coincidence between the occurrence of the oilseed rape pests and the actual assessment of the web density of Linyphiid spiders ............... 144 -D. brassicae........................................................................................... 144 -Meligethesspp....................................................................................... 145 -C. assimilis............................................................................................ 145 Permanent assessment of the web density of Linyphiid spiders .................... 155 Temporal coincidence between the occurrence of the oilseed rape pests and the permanent assessment of the web density of Linyphiid spiders ........ 155 -D. brassicae........................................................................................... 155 -Meligethesspp....................................................................................... 156 -C. assimilis............................................................................................ 157 Correlations between the web density and the occurrence of the oilseed rape pests ........................................................................................................ 166 -Discussion............................................................................................................ 167 -Conclusions......................................................................................................... 171 -Summary............................................................................................................. 172 -References........................................................................................................... 173

Discussion ................................................................................................................ 176 Conclusions ............................................................................................................. 179 Summary......................................................................................................... 180 References ............................................................................................................... 181 Growth stages and BBCH-identification keys of oilseed rape................... 184 List of abbreviations....................................................................................... 186 Acknowledgements ................................................................................................ 188

III

The spatio-temporal dynamics of epigaeic predators and insect pests in different oilseed rape management systems

Introduction In 2002, the EU-project MASTER –MAnagementSTrategies forEuropean oilseedRape pests – started in six countries in northern Europe. In the UK, Germany, Sweden, Finland, Poland and Estonia investigations were carried out to find economically-viable and environmentally less harmful Integrated Pest Management (IPM) Strategies for oilseed rape. Aim of the project was to address knowledge gaps for the first time and to identify the key parasitoid, predator and pathogen species of the oilseed rape pests and to determine the factors affecting their abundance, phenology and distribution. Oilseed rape is an important th crop in European agriculture, having gained importance particularly in the late 20 century (B UNTING , 1986). Seed from oilseed rape is crushed to extract the oil, which is used for culinary purposes, for fuel and as a lubricant, especially in the food-processing industry. The seed-cake is used for cattle fodder. In northern Europe, oilseed rape is attacked by various insect pests (A LFORD  et al., 2003), many of which are of considerable economic importance. The following pests are considered of particular significance on oilseed rape crops in Europe, although not in all regions: -cabbage stem flea beetle –Psylliodes chrysocephala -brassica pod midge –Dasineura brassicae -pollen beetle –Meligethesspp. (especiallyM.aeneus) -cabbage seed weevil –Ceutorhynchusassimilis -cabbage stem weevil –Ceutorhynchuspallidactylus -rape stem weevil –Ceutorhynchusnapi The management of these pests still mainly relies on chemical pesticides. These are often applied routinely and prophylactically, often without regard to pest incidence. At best the pesticides are used according to threshold values of the pest population. This leads to over-use of pesticides which reduces the economic competitiveness of the crop and threatens biological diversity. The pesticides kill the naturally-occurring antagonists of the pests, which would otherwise be a resource of great potential benefit to the farmer. Historically, pesticides have provided a reliable approach to pest and disease control in arable crops (W ALTERS  et al., 2003). The most used group of insecticides on oilseed rape in Europe are pyrethroids. Recent reports indicate that pollen beetles have developed resistance to pyrethroids and can no longer be controlled successfully by this group of pesticides (H ANSEN , 2003; D ECOIN al., 2005; et N ILSSON et al., 2003). The occurrence of resistance to pesticides within pest populations has often been answered by developing new classes of pesticides or by improving management techniques like the establishment of effective pest assessment methods, optimal timing of pesticide applications (W ALTERS al., 2003) and the development of computer decision- et support models (H ARDWICK , 1998; M ORGAN et al., 2000). The need to reduce the reliance on chemical solutions for pest control has lead to the investigation of biological pest management methods. Classical biological control techniques were originally used in greenhouse-grown crops. The transfer of these methods to field-grown crops is difficult:

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The spatio-temporal dynamics of epigaeic predators and insect pests in different oilseed rape management systems

Owing to the costs involved, it is currently uneconomic to artificially introduce biocontrol agents (BCAs) to field-grown crops (W ALTERS al., 2003). Biocontrol strategies in arable et crops focus on preserving and enhancing the occurrence of naturally-occurring predators of the pest populations. In 1997, the International Organisation for Biological and Integrated Control of Noxious Animals and Plants (IOBC) published Guidelines for Integrated Production of Arable Crops in Europe (B OLLER et al., 1997). These advocated the use of biological, bio-technical, physical and agronomic methods rather than chemical methods of plant protection. The only options for oilseed rape were the establishment of flowering border strips to deter pests and attract natural enemies of the pests and the use of economic thresholds to determine the need to apply insecticides. The MASTER-project aimed at the evidence that naturally-occurring agents of biocontrol like parasitoids, predators and pathogens that attack the oilseed rape pests can provide economically-viable control of some pests and reduce the need for insecticides. Oilseed rape pests are attacked by a wide range of naturally-occurring enemies, many of which help to reduce the pest populations (A LFORD al., 2003). Unlike certain parasitoids et they do not specifically target oilseed rape pests, but tend to be opportunist feeders that attack a wide range of prey. Ground beetles and rove beetles (Coleoptera: Carabidae and Staphylinidae) as well as spiders (Arachnida: Araneae) are the main epigaeic predators in oilseed rape (B ÜCHS A & LFORD , 2003). The oilseed rape pest larvae drop from the rape canopy to the soil for pupation; there they are easily available for the epigaeic predators. Predators are often abundant in oilseed rape fields and their potential for exerting pest control is considerable. However, unlike certain parasitoids, they do not specifically target oilseed rape pests. Carabidae, Staphylinidae and Araneae are feeders that attack a wide range of prey; nevertheless, fully grown oilseed rape pest larvae are likely to feature as important components of their diet (B ÜCHS & A LFORD , 2003). It was assumed that epigaeic predators can be supported in their occurrence by suitable cultivation techniques and that their role in pest control can be enhanced. Whereas some publications give evidence of carabids as antagonists of insect pests in cereals (B ASEDOW , 1973; S UNDERLAND V & ICKERMANN , 1980; G RIFFITHS , 1982; C HAMBERS  et al., 1983; S CHELLER , 1984; P OEHLING al., 1985; C et HIVERTON , 1988; E KBOM  et al., 1993) with particular emphasis on their impact on cereal aphids, but there are very few publications on predator-prey relationships in oilseed rape. Aim of this study was to determine the factors affecting the predators’ abundance, phenology and distribution and to investigate the predator-prey relationship in oilseed rape. This study reveals the results from the field trials of the MASTER-project in Braunschweig- Wendhausen, Germany. An Integrated Crop Management (ICM) system with reduced tillage and without insecticide sprays and a ploughed standardised management (STN) system with insecticide treatments after economic pest thresholds were compared with regard to the infestation of the crop with the insect pests and the occurrence of epigaeic predators. During the project, two additional subsystems were installed and included in the investigations: an - 2 -

The spatio-temporal dynamics of epigaeic predators and insect pests in different oilseed rape management systems

ICM-subsystem with insecticide treatments and a STN-subsystem with insecticide sprays irrespective of pest thresholds. The spatial and temporal distribution both of predators and pests in the oilseed rape were examined and compared with each other. In agroecosystems, knowledge of spatial and temporal dynamics can lead to improvements in the design of integrated pest control and facilitate adoption of precision agriculture (B RENNER et al., 1998). The spatio-temporal distributions of oilseed rape pests and predators were therefore compared and tested for association. To describe the spatial distribution the SADIE- (SpatialAnalysis byDistanceIndicEs) technique was used, which can detect and measure the degree of spatial pattern in spatially-referenced count data (P ERRY , 1998a & b; P ERRY et al., 1999). In the first chapter, the infestation of the crop with the different pests, the emergence of the new pest generations and the activity density of the epigaeic predators in the different management systems are reported. Details of the temporal coincidence between pest larval dropping and the activity density of the carabids, staphylinids and spiders in the different oilseed rape management systems are given. The emergence of the predators and the pests in the following crop winter wheat is described. In the second chapter, the spatial distribution of pest larvae and epigaeic predators and the temporal coincidence between the larval dropping and the activity density of the predators are illustrated. Aim of this part of the MASTER-project was to identify for the first time key predator species of the different oilseed rape pests. During the experiments of the MASTER-project, a high dropping of Staphylinidae larvae from the oilseed rape canopy has been recorded. These larvae are possible antagonists of the pollen beetle larvae in the oilseed rape flower stands. In the third chapter of this study, for the first time the larval dropping ofMeligethesspp. and the spatio-temporal relationship with the dropping of the rove beetle larvae in the different oilseed rape management systems are described. In the fourth chapter, the effects of the different oilseed rape management systems on the web density of the linyphiid spiders, which build their webs on the soil surface, and of the spider Theridion impressum, whose webs can be found in the oilseed rape flower stands and on the pods, are reported. The influence of the different management systems on the temporal coincidence between the pest larval dropping and the web density has been investigated in this study. REFERENCES Alford, D.V.; Nilsson, C.; Ulber, B. (2003): Insect pests of oilseed rape crops. – In: Biocontrol of Oilseed Rape Pests. Ed. D. Alford, Blackwell Science, 9-41. Basedow, T. (1973): Der Einfluss epigäischer Raubarthropoden auf die Abundanz phytophager Insekten in der Agrarlandschaft. –Pedobiologia13, 410-422.

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