Lene Sigsgaard | University of Copenhagen (original) (raw)

Papers by Lene Sigsgaard

The benefits of functional biodiversity (FB) for pest control are under debate among practitioner... more The benefits of functional biodiversity (FB) for pest control are under debate among practitioners. Little is known about farmers' practices and motivations to foster FB. We assume that the use of monitoring methods would help the farmers to better appreciate the benefits of FB and thus implement favorable practices. Therefore, we undertook a comprehensive strategy consisting of semi-directive interviews and participatory workshops to describe farmers' practices and perception, and design monitoring methods adapted to their needs. Our findings provide empirical evidence that FB is associated with multiple services and dis-services. Additionally, the farmers' experience and time are two important conditions for farmers' involvement for FB. Four main attitudes towards the management of FB were characterized: waitand-see, naturalist, regulation, and multifunctional. These attitudes provide a useful framework to design support tools and research programs in line with farmers' needs Introduction: Supporting functional biodiversity (FB), which provides natural pest regulation, is an environmentally sound and promising approach to reduce pesticide use in perennial cultures such as apple, especially in organic farming (OF). However, little is known about farmers' practices to implement favorable FB techniques or farmers' expectations of FB mediated pest regulation. In fact, FB-supporting techniques (FB-techniques) are massively questioned by practitioners due to inadequate information about their effectiveness. Even the farmers who attempt to favor on-farm biodiversity often lack the means to evaluate how their actions may contribute in practice to FB. We assumed here that to develop useful and appropriate monitoring methods, it is necessary to take into account the variety of knowledge, perceptions and interests about functional biodiversity. Material and methods: We combined three different approaches.

Le strisce fiorite perenni migliorano l'efficacia della lotta biologica contro i parassiti ne... more Le strisce fiorite perenni migliorano l'efficacia della lotta biologica contro i parassiti nella frutticoltura. La guida tecnica presenta i risultati del progetto europeo EcoOrchard e di altri studi, spiega come funzionano le strisce fiorite e come vengono utilizzate nella pratica.

Forschungsinstitut für biologischen Landbau (FiBL) eBooks, 2018

Perennial flower strips improve the effectiveness of biological pest control by predators and par... more Perennial flower strips improve the effectiveness of biological pest control by predators and parasitoids in fruit production. The guide presents results from the European EcoOrchard project and other studies, explains how the flower strips function, introduces suitable plants and describes step by step the procedure for planting and maintenance. The information is supplemented by information on the costs and possible disadvantages of the flowering strips.

Sur une partie du verger gérée avec une pratique agroécologique (par ex. un fauchage limité) ;  ... more Sur une partie du verger gérée avec une pratique agroécologique (par ex. un fauchage limité) ;  Pour observer l'effet d'un traitement (observation avant et après le traitement) ;  Pour suivre l'évolution dans le temps des arthropodes à des moments clés de la saison, comme l'apparition dans le verger ou le pic d'abondance d'un insecte (en fonction des cycles biologiques des populations visées, cf. fiches méthodes). Dans le cas où les méthodes sont utilisées pour comparer les auxiliaires entre deux modalités (deux zones d'un même verger ou deux parcelles différentes), l'une étant agroécologique et l'autre étant le témoin, il est important de s'assurer que les suivis témoins sont réalisés à distance d'infrastructures agroécologiques qui pourraient biaiser les résultats. Idéalement, les suivis témoins devraient être distants de 50m de toute IAE, comme le montre le schéma ci-dessus. De nombreux facteurs déterminent la présence d'insectes dans une parcelle (paysage, pratique, variété et âge des arbres, ...). Il est important de les prendre en compte quand on compare les résultats de suivis réalisés dans des parcelles différentes. Les animateurs de l'atelier seront à disposition des arboriculteurs pour identifier dans une exploitations quelles sont les deux parcelles ou zones qu'il est le plus intéressant et pertinent de comparer (on pourra s'aider pour cela d'images satellites qui donnent une bonne idée de l'organisation spatiale des arbres et des IAE dans les vergers). 50 m 50 m Schéma illustrant une manière d'utiliser la méthode de suivi : observation de l'effet de la distance à une IAE Arbre suivi près de l'IAE (modalité A) Arbre du verger non suivi Arbre 'témoin' suivi (modalité B)

Blomsterbraemmer kan give flere nyttedyr og hermed bidrage til regulering af aeblevikler og andre... more Blomsterbraemmer kan give flere nyttedyr og hermed bidrage til regulering af aeblevikler og andre skadedyr i økologiske aebleplantager. Naturlig regulering Den danske økologiske produktion af frugt og baer daekker i dag 502 ha. Den største afgrøde er aebler med 282 ha. Skadedyr og sygdomme giver kvalitets-og udbyttetab i økologiske aebler. Det betyder at den danske produktion er lille og ustabil. Der er samtidig et stort potentiale for at øge produktionen af økologiske aebler i Danmark, da interessen for at spise økologisk er stigende. Forebyggelse er afgørende for på langt sigt at opnå øget produktion. En vigtig del af forebyggelse er at beskytte de natuligt forekommende nyttedyr så de kan bidrage til at regulere skadedyrene. Hermed kan behovet for direkte bekaempelse reduceres. Som en del af projektet Fruitgrowth undersøger vi betydningen af blomsterbraemmer for den naturlige regulering af aeblevikleren i økologiske aebleplantager. AEbleviklerens larve kaldes populaert for 'orm' i aebler.

Ecological infrastructures in apple orchards may reduce pest infestation by improving conditions ... more Ecological infrastructures in apple orchards may reduce pest infestation by improving conditions for natural enemies. The present study assessed the density of overwintering codling moth Cydia pomonella L. (Lepidoptera, Tortricidae), level of parasitism, infestation by entomopathogenic fungi and other mortality factors in five organic orchards with flower strips and five organic orchards without flower strips. In orchards with flower or grassy strips, predation on sentinel prey was assessed in different distances from the strips. No clear difference was found between infestation levels in organic orchards with and without flower strips. Within orchards with flower strips mortality of codling moth larvae collected near flower strips was higher than for larvae collected further away from strips. Likewise mortality of sentinel eggs was higher in trees near the flower strip than further way. Lack of difference between orchards with and without flower strips could be a result of high variability between orchards. Within orchards with flower strips, there was increased predation activity and increased mortality of codling moth larvae from near flower strips that could be predator induced.

Ecological Indicators, Oct 1, 2021

Biocontrol, May 10, 2018

The predator Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae) and the generalist entomop... more The predator Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae) and the generalist entomopathogenic fungus Metarhizium brunneum Petch (Hypocreales: Clavicipitaceae) are effective biological control agents that can co-occur in pest management programmes. We exposed larvae to M. brunneum, on leaves and in soil, to explore possible outcomes of combining the two natural enemies. The number of emerging adults and their longevity were negatively affected by fungus in the soil. When exposed on leaves, adult emergence was unaffected but longevity was reduced. In choice experiments, females chose to lay eggs on fungus-free leaves: more control leaves had eggs and there were more eggs per leaf in the control. In no-choice experiments, the same frequency of females laid eggs in the treatment and control, but significantly more eggs were laid on the control leaves. Gravid A. aphidimyza can perceive M. brunneum and respond by choosing fungus-free oviposition sites, thus reducing contact between them.

Insects, Aug 11, 2019

Functional biodiversity is of fundamental importance for pest control. Many natural enemies rely ... more Functional biodiversity is of fundamental importance for pest control. Many natural enemies rely on floral resources to complete their life cycle. Farmers need to ensure the availability of suitable and sufficient floral biodiversity. This review summarizes 66 studies on the management of floral biodiversity in apple orchards, published since 1986. Approaches followed different degrees of intervention: short-term practices (mowing regime and weed maintenance, cover crops), establishment of durable ecological infrastructures (perennial flower strips, hedgerows) and redesign of the crop system (intercropping, agroforestry). Although short-term practices did not always target the nutrition of natural enemies by flowering plants, living conditions for them (alternative prey, provision of habitat) were often improved. Perennial flower strips reliably enhanced natural enemies and techniques for their introduction continuously developed. Resident natural enemies and their impact in pest control reacted positively to the introduction of a more diversified vegetation, whereas the response of very mobile organisms was often not directly linked to the measures taken. A careful selection and management of plants with particular traits exploitable by most natural enemies emerged as a key-point for success. Now the elaborated design of such measures needs to be adopted by stakeholders and policy makers to encourage farmers to implement these measures in their orchards.

The EcoOrchard project (2015-18) has produced a handbook on FAB assessment in dialogue with growe... more The EcoOrchard project (2015-18) has produced a handbook on FAB assessment in dialogue with growers and advisors and a technical guideline for FAB orchard management. Orchards are perennial cultures, and, especially in organic fruit production, it is essential to design and manage orchards in a way which favours predators and parasitoids over pests. Increasing plant biodiversity and habitats in such a way that beneficial organisms are favoured is called Functional Agrobiodiversity (FAB). The value of FAB for reducing pesticide use in fruit production is generally acknowledged, and many organic fruit growers try to increase it in spite of a shortage of information on FAB, economical and technical challenges and lack of situation-specific, detailed advice. To improve this situation, ECOORCHARD combined several complementary approaches and prioritizes making information and tools about FAB available to practitioners.

The benefits of functional biodiversity (FB) for pest control are under debate among practitioner... more The benefits of functional biodiversity (FB) for pest control are under debate among practitioners. Little is known about farmers' practices and motivations to foster FB. We assume that the use of monitoring methods would help the farmers to better appreciate the benefits of FB and thus implement favorable practices. Therefore, we undertook a comprehensive strategy consisting of semi-directive interviews and participatory workshops to describe farmers' practices and perception, and design monitoring methods adapted to their needs. Our findings provide empirical evidence that FB is associated with multiple services and dis-services. Additionally, the farmers' experience and time are two important conditions for farmers' involvement for FB. Four main attitudes towards the management of FB were characterized: waitand-see, naturalist, regulation, and multifunctional. These attitudes provide a useful framework to design support tools and research programs in line with farmers' needs Introduction: Supporting functional biodiversity (FB), which provides natural pest regulation, is an environmentally sound and promising approach to reduce pesticide use in perennial cultures such as apple, especially in organic farming (OF). However, little is known about farmers' practices to implement favorable FB techniques or farmers' expectations of FB mediated pest regulation. In fact, FB-supporting techniques (FB-techniques) are massively questioned by practitioners due to inadequate information about their effectiveness. Even the farmers who attempt to favor on-farm biodiversity often lack the means to evaluate how their actions may contribute in practice to FB. We assumed here that to develop useful and appropriate monitoring methods, it is necessary to take into account the variety of knowledge, perceptions and interests about functional biodiversity. Material and methods: We combined three different approaches.

Le strisce fiorite perenni migliorano l'efficacia della lotta biologica contro i parassiti ne... more Le strisce fiorite perenni migliorano l'efficacia della lotta biologica contro i parassiti nella frutticoltura. La guida tecnica presenta i risultati del progetto europeo EcoOrchard e di altri studi, spiega come funzionano le strisce fiorite e come vengono utilizzate nella pratica.

Forschungsinstitut für biologischen Landbau (FiBL) eBooks, 2018

Perennial flower strips improve the effectiveness of biological pest control by predators and par... more Perennial flower strips improve the effectiveness of biological pest control by predators and parasitoids in fruit production. The guide presents results from the European EcoOrchard project and other studies, explains how the flower strips function, introduces suitable plants and describes step by step the procedure for planting and maintenance. The information is supplemented by information on the costs and possible disadvantages of the flowering strips.

Sur une partie du verger gérée avec une pratique agroécologique (par ex. un fauchage limité) ;  ... more Sur une partie du verger gérée avec une pratique agroécologique (par ex. un fauchage limité) ;  Pour observer l'effet d'un traitement (observation avant et après le traitement) ;  Pour suivre l'évolution dans le temps des arthropodes à des moments clés de la saison, comme l'apparition dans le verger ou le pic d'abondance d'un insecte (en fonction des cycles biologiques des populations visées, cf. fiches méthodes). Dans le cas où les méthodes sont utilisées pour comparer les auxiliaires entre deux modalités (deux zones d'un même verger ou deux parcelles différentes), l'une étant agroécologique et l'autre étant le témoin, il est important de s'assurer que les suivis témoins sont réalisés à distance d'infrastructures agroécologiques qui pourraient biaiser les résultats. Idéalement, les suivis témoins devraient être distants de 50m de toute IAE, comme le montre le schéma ci-dessus. De nombreux facteurs déterminent la présence d'insectes dans une parcelle (paysage, pratique, variété et âge des arbres, ...). Il est important de les prendre en compte quand on compare les résultats de suivis réalisés dans des parcelles différentes. Les animateurs de l'atelier seront à disposition des arboriculteurs pour identifier dans une exploitations quelles sont les deux parcelles ou zones qu'il est le plus intéressant et pertinent de comparer (on pourra s'aider pour cela d'images satellites qui donnent une bonne idée de l'organisation spatiale des arbres et des IAE dans les vergers). 50 m 50 m Schéma illustrant une manière d'utiliser la méthode de suivi : observation de l'effet de la distance à une IAE Arbre suivi près de l'IAE (modalité A) Arbre du verger non suivi Arbre 'témoin' suivi (modalité B)

Blomsterbraemmer kan give flere nyttedyr og hermed bidrage til regulering af aeblevikler og andre... more Blomsterbraemmer kan give flere nyttedyr og hermed bidrage til regulering af aeblevikler og andre skadedyr i økologiske aebleplantager. Naturlig regulering Den danske økologiske produktion af frugt og baer daekker i dag 502 ha. Den største afgrøde er aebler med 282 ha. Skadedyr og sygdomme giver kvalitets-og udbyttetab i økologiske aebler. Det betyder at den danske produktion er lille og ustabil. Der er samtidig et stort potentiale for at øge produktionen af økologiske aebler i Danmark, da interessen for at spise økologisk er stigende. Forebyggelse er afgørende for på langt sigt at opnå øget produktion. En vigtig del af forebyggelse er at beskytte de natuligt forekommende nyttedyr så de kan bidrage til at regulere skadedyrene. Hermed kan behovet for direkte bekaempelse reduceres. Som en del af projektet Fruitgrowth undersøger vi betydningen af blomsterbraemmer for den naturlige regulering af aeblevikleren i økologiske aebleplantager. AEbleviklerens larve kaldes populaert for 'orm' i aebler.

Ecological infrastructures in apple orchards may reduce pest infestation by improving conditions ... more Ecological infrastructures in apple orchards may reduce pest infestation by improving conditions for natural enemies. The present study assessed the density of overwintering codling moth Cydia pomonella L. (Lepidoptera, Tortricidae), level of parasitism, infestation by entomopathogenic fungi and other mortality factors in five organic orchards with flower strips and five organic orchards without flower strips. In orchards with flower or grassy strips, predation on sentinel prey was assessed in different distances from the strips. No clear difference was found between infestation levels in organic orchards with and without flower strips. Within orchards with flower strips mortality of codling moth larvae collected near flower strips was higher than for larvae collected further away from strips. Likewise mortality of sentinel eggs was higher in trees near the flower strip than further way. Lack of difference between orchards with and without flower strips could be a result of high variability between orchards. Within orchards with flower strips, there was increased predation activity and increased mortality of codling moth larvae from near flower strips that could be predator induced.

Ecological Indicators, Oct 1, 2021

Biocontrol, May 10, 2018

The predator Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae) and the generalist entomop... more The predator Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae) and the generalist entomopathogenic fungus Metarhizium brunneum Petch (Hypocreales: Clavicipitaceae) are effective biological control agents that can co-occur in pest management programmes. We exposed larvae to M. brunneum, on leaves and in soil, to explore possible outcomes of combining the two natural enemies. The number of emerging adults and their longevity were negatively affected by fungus in the soil. When exposed on leaves, adult emergence was unaffected but longevity was reduced. In choice experiments, females chose to lay eggs on fungus-free leaves: more control leaves had eggs and there were more eggs per leaf in the control. In no-choice experiments, the same frequency of females laid eggs in the treatment and control, but significantly more eggs were laid on the control leaves. Gravid A. aphidimyza can perceive M. brunneum and respond by choosing fungus-free oviposition sites, thus reducing contact between them.

Insects, Aug 11, 2019

Functional biodiversity is of fundamental importance for pest control. Many natural enemies rely ... more Functional biodiversity is of fundamental importance for pest control. Many natural enemies rely on floral resources to complete their life cycle. Farmers need to ensure the availability of suitable and sufficient floral biodiversity. This review summarizes 66 studies on the management of floral biodiversity in apple orchards, published since 1986. Approaches followed different degrees of intervention: short-term practices (mowing regime and weed maintenance, cover crops), establishment of durable ecological infrastructures (perennial flower strips, hedgerows) and redesign of the crop system (intercropping, agroforestry). Although short-term practices did not always target the nutrition of natural enemies by flowering plants, living conditions for them (alternative prey, provision of habitat) were often improved. Perennial flower strips reliably enhanced natural enemies and techniques for their introduction continuously developed. Resident natural enemies and their impact in pest control reacted positively to the introduction of a more diversified vegetation, whereas the response of very mobile organisms was often not directly linked to the measures taken. A careful selection and management of plants with particular traits exploitable by most natural enemies emerged as a key-point for success. Now the elaborated design of such measures needs to be adopted by stakeholders and policy makers to encourage farmers to implement these measures in their orchards.

The EcoOrchard project (2015-18) has produced a handbook on FAB assessment in dialogue with growe... more The EcoOrchard project (2015-18) has produced a handbook on FAB assessment in dialogue with growers and advisors and a technical guideline for FAB orchard management. Orchards are perennial cultures, and, especially in organic fruit production, it is essential to design and manage orchards in a way which favours predators and parasitoids over pests. Increasing plant biodiversity and habitats in such a way that beneficial organisms are favoured is called Functional Agrobiodiversity (FAB). The value of FAB for reducing pesticide use in fruit production is generally acknowledged, and many organic fruit growers try to increase it in spite of a shortage of information on FAB, economical and technical challenges and lack of situation-specific, detailed advice. To improve this situation, ECOORCHARD combined several complementary approaches and prioritizes making information and tools about FAB available to practitioners.