Coccinellid Response To Landscape Composition And Configuration

Arthropod natural enemies provide valuable pest suppression in agricultural landscapes. Natural enemy abundance and diversity within a given crop, in turn, have frequently been shown to be positively related to the amount of semi-natural habitat in the landscape. However, other aspects of landscape structure may also influence natural enemy communities and may be more amenable to management. We simultaneously assessed the relationship among several metrics of landscape structure, as well as between these metrics and coccinellid activity in soybean fields. We used partial least squares regression to examine the coccinellid response to landscape structure. Coccinellid activity was lowest in landscapes dominated by annual crops grown in large fields and highest in landscapes dominated by semi-natural habitats such as grasslands and forests, with a higher diversity of crops grown in smaller fields. Landscape characteristics, including composition factors such as the type and amount of different land covers and configuration factors such as the interspersion of these land covers, are often correlated within a set of landscapes. Isolating the effects of individual landscape characteristics on natural enemy communities will be necessary to move forward with the development of management actions that can increase biocontrol services in agroecosystems.