Effects of landscape context and agricultural management practices on insect diversity and biological pest control

TERRECO WP 3-07

Goal within the TERRECO Assessments:

• Evaluation in the Haean-myun Basin and along gradients of landscape complexity of correlated changes in insect populations and their ecosystem services
• Development of statistical models to predict changes in insect biodiversity with agricultural practices, land use intensity, landscape pattern and remote sensing indices

Abstract: Landscape context and management intensity are major determinants of biodiversity patterns in agricultural landscapes, particularly those associated with biological pest control. In Haean, South Korea, we investigated the influence of landscape and management on the diversity of insect natural enemies and on their performance for pest control at multiple spatial scales. Results show that enemy diversity is generally higher in complex landscapes and in organic fields, and that different enemy guilds react to the landscape at different scales. Herbivory rates show a positive relationship with the abundance of natural enemies; a further exclusion experiment aims to clarify the direction and nature of this relationship and associated multitrophic interactions. In a separate experiment, herbivory rates are shown to increase with increased fertilizer input, while the presence of enemy pressure led to 20-60% decreased damage in all four fertilizer treatments.

Keywords: insect diversity, biological pest control, landscape ecology, multitrophic interactions, scale

project description in detail from proceedings of 2011 TERRECO Science Conference GAP