Relationships between biodiversity and biological control in agroecosystems: Current status and future challenges

• Published in: Biological control 2014-08, Vol.75, p.8-17
• Main Authors: Crowder, David W., Jabbour, Randa
• Format: Article
• Language: English
• Subjects: Agricultural intensification; Agronomy. Soil science and plant productions; Animal and plant ecology; Animal, plant and microbial ecology; Applied ecology; Arthropoda; Biological and medical sciences; Conservation; Ecosystem functioning; Evenness; Fundamental and applied biological sciences. Psychology; General agroecology; General agroecology. Agricultural and farming systems. Agricultural development. Rural area planning. Landscaping; General agronomy. Plant production; Generalities. Agricultural and farming systems. Agricultural development; Phytopathology. Animal pests. Plant and forest protection; Richness; Synecology
• ISSN: 1049-9644; 1090-2112
• DOI: 10.1016/j.biocontrol.2013.10.010

•Agricultural systems are intensifying to keep up with growing human demands.•Intensive agriculture can negatively impact biodiversity and biological control.•We review biodiversity and biological control of arthropod and weedy pests.•We discuss similarities and differences between biocontrol of arthropods and weeds.•We suggest novel approaches for examining biodiversity and biological control. Agricultural systems around the world are faced with the challenge of providing for the demands of a growing human population. To meet this demand, agricultural systems have intensified to produce more crops per unit area at the expense of greater inputs. Agricultural intensification, while yielding more crops, generally has detrimental impacts on biodiversity. However, intensified agricultural systems often have fewer pests than more “environmentally-friendly” systems, which is believed to be primarily due to extensive pesticide use on intensive farms. In turn, to be competitive, less-intensive agricultural systems must rely on biological control of pests. Biological pest control is a complex ecosystem service that is generally positively associated with biodiversity of natural enemy guilds. Yet, we still have a limited understanding of the relationships between biodiversity and biological control in agroecosystems, and the mechanisms underlying these relationships. Here, we review the effects of agricultural intensification on the diversity of natural enemy communities attacking arthropod pests and weeds. We next discuss how biodiversity of these communities impacts pest control, and the mechanisms underlying these effects. We focus in particular on novel conceptual issues such as relationships between richness, evenness, abundance, and pest control. Moreover, we discuss novel experimental approaches that can be used to explore the relationships between biodiversity and biological control in agroecosystems. In particular, we highlight new experimental frontiers regarding evenness, realistic manipulations of biodiversity, and functional and genetic diversity. Management shifts that aim to conserve diversity while suppressing both insect and weed pests will help growers to face future challenges. Moreover, a greater understanding of the interactions between diversity components, and the mechanisms underlying biodiversity effects, would improve efforts to strengthen biological control in agroecosystems.