Award details

Quantification of resource bottlenecks in agro-ecosystems and their impact on insect-based ecosystem services

Reference	BB/G017468/1
Principal Investigator / Supervisor	Professor Felix Wackers
Co-Investigators / Co-Supervisors	Dr Gregory Masters, Dr Emma Morley
Institution	Lancaster University
Department	Lancaster Environment Centre
Funding type	Skills
Value (£)	74,410
Status	Completed
Type	Training Grants
Start date	01/12/2009
End date	30/11/2013
Duration	48 months

Abstract

unavailable

Summary

Insect predators and parasitoids are crucial in driving population dynamics of herbivorous arthropods. As biological pest control agents they provide a valuable ecosystem service helping secure the production of safe and healthy food. However, in agro-ecosystems the effectiveness of predators and parasitoids can be severely constrained by a range of factors including the lack of alternative prey, floral resources, and suitable overwintering sites (Wäckers et al. 2005). Agro-ecosystem projects increasingly seek to optimize insect-based ecosystem services such as biological pest control and pollination by modifying the agro-environment in a way that removes or minimizes these impediments (Olson and Wäckers 2007). In order to identify bottlenecks that limit ecosystem services and to assess the success of 'Biodiversity Programs' in alleviating these limiting factors, we need to be able to study the constraints that act upon individual insects under field conditions. Recently developed tools allow us to better investigate energetic reserves, feeding history, reproductive success and age structure of field collected insects (Steppuhn and Wäckers 2004). This provides unique opportunities to gain novel insights in how landscape structure and composition impacts ecosystem services such as biological pest control. Results from this study will be applied to optimize sustainable agricultural production through targeted landscape management. This supports the integration of ecosystem service provision with production delivery in intensive agricultural systems. OBJECTIVES: To identify and quantify resource bottlenecks for predators and parasitoids in current agricultural production. METHODOLOGY: Semi-field as well as field experiments will be conducted using a factorial design to investigate the relative impact of alternative prey, floral food, and overwintering sites on predator-prey dynamics. Overwintering sites: This treatment will consist of grassy perennial field margins, which will be cut at regular intervals during cropping season to prevent flowering and to minimize infestation by alternative aphid prey. Floral food supplements: Flowering annual herbs will be selected on the basis of their suitability as nectar/pollen source for biological control agents and the fact that they present low levels of alternative prey (Wäckers, 2004). Alternative prey: To provide this resource, a mixture of perennial plant species will be selected on the basis of their susceptibility for non-pest aphids. Part of the plots will ploughed at the end of the growing season, to study the impact of winter refuge. Throughout the year, resource plots as well as adjacent fields will be sampled for predators, parasitoids and aphids. Screen cages will be used to record successful overwintering. Nectar and pollen feeding by field collected individuals will be assessed using well established HPLC analysis methodology. Whereas the importance of alternative prey, floral resources, and winter refuge for predators and parasitoids has been widely recognized, we know very little about their respective role in enhancing natural pest control. Currently, field margins or set-asides often only provide a subset of these resources (Olson and Wäckers 2007). By addressing the relative impact of individual resources on predator/prey and parasitoid/host dynamics we will be able to disentangle these factors and to identify the principal resource bottleneck in current agro-ecosystems. We will focus on aphids, as they represent important pest in a broad range of crops, inflicting both direct damage and acting as the main vector of plant viruses.

Committee	Not funded via Committee
Research Topics	X – not assigned to a current Research Topic
Research Priority	X – Research Priority information not available
Research Initiative	X - not in an Initiative
Funding Scheme	Training Grant - Industrial Case

I accept the terms and conditions of use (opens in new window)

export PDF file

back to list new search