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Habitat diversification and aphid-specific natural enemies in arable ecosystems: optimising crop protection and environmental benefits - AR0318

Description
The overall objective of this project is to identify and optimise the beneficial pest management and environmental effects of botanical diversification in and around crops in the arable crop ecosystem. Use will be made of existing non-crop habitat plots established in other projects, such as LINK projects and the ‘BUZZ’ project, as well as replicated field plots established in this new project, to identify the most effective plants and plant mixes to provide essential resources for beneficial insect and pest natural enemies within the arable crop ecosystem. These habitats will include wildlife mixtures recommended in current agri-environment schemes. The focus will be on the provision of resources such as non-insect food for adult parasitoids and predators, as well as host and prey populations at times of the year when these resources are not provided by the crop itself.

Detailed studies of the effects of these resources on key aphid-specific natural enemies, such as parasitoids and entomopathogenic fungi, will exploit newly-available techniques. These will include the marking of parasitoids with immunoglobulins for mark-release-recapture studies of dispersal movements between crop and non-crop habitats, sugar analysis of parasitoids to identify food sources and to quantify parasitoid nutritional status and species-specific molecular markers to distinguish entomopathogen inocula in pathogen dispersal studies. The importance of positive interactions between different natural enemies, especially the role of insect parasitoids and predators in aiding the dispersal of entomopathogen spores between crop and non-crop habitats and between host colonies, will be determined using semi-field experiments, exploiting experimentally-tractable parasitoid species as a model.

The potential of combining the targeted botanical diversification of the arable crop ecosystem with recent advances in the semiochemical manipulation of insect behaviour to overcome current constraints to the use of augmentative releases of biological control agents in arable crop ecosystems will also be investigated.

The work is relevant to Defra policy objectives of promoting a sustainable, competitive and safe food chain and promoting sustainable, diverse, modern and adaptable farming. The results will be disseminated to both the scientific and farming communities through scientific publications, articles in the farming press and demonstrations at farming events such as ‘Cereals’. The results will aid the development of advice for the sustainable management of the arable crop ecosystem and will underpin current and future LINK projects on habitat management on arable farmland.
Objective
The overall objective is to identify and optimise the beneficial pest management and environmental effects of botanical diversification in and around crops in the arable ecosystem.

Specific scientific objectives are:

1. To identify the most effective plants or plant mixes (including Countryside Stewardship wildlife mixtures) to establish as natural enemy reservoir habitats in and around arable crops, and determine the essential resources (food, hosts/prey, overwintering sites) used by natural enemies in these habitats at times when resources are not available in the crop.
2. To measure the effects of potential reservoir habitats on the biodiversity of beneficial organisms.
3. To determine if aphid parasitoids feed on honeydew in non-crop habitats prior to crop colonisation in spring and autumn and to measure the effects of honeydew and/or floral nectar consumption on parasitoid fitness and P. neoaphidis transmission.
4. To measure the dispersal movements of natural enemies between reservoir and crop habitats.
5. To quantify the arrestment effects of Nepeta-derived semiochemicals on aphid parasitoids and selected predators and assess their potential for enabling augmentative releases into crop and reservoir habitats.
6. To develop and test the viability of augmentative release strategies for aphid parasitoids and the entomopathogen P. neoaphidis in arable ecosystems containing appropriate non-crop habitats.
Project Documents
• Final Report : Habitiat diversification and aphid-specific natural enemies in arable ecosystems: optimising crop protection and environmental benefits   (383k)
Time-Scale and Cost
From: 2004

To: 2007

Cost: £768,750
Contractor / Funded Organisations
Rothamsted Research (BBSRC)
Keywords
Climate and Weather              
Climate Change              
Environmental Protection              
Natural Resource Use              
Sustainable Farming and Food              
Sustainable Production              
Fields of Study
Arable Crops