Contrasting the farm-scale spatio-temporal dynamics of boundary and field overwintering predatory beetles in arable crops

Abstract

In many European countries agri-environment funding can improve ecosystem services, including the adoption of conservation biocontrol, through the creation of habitats that encourage beneficial arthropods. Predatory beetles are amongst the most numerous and diverse arthropods present in arable fields. The primary ecosystem services provided by predatory beetles are in biological control and food chain maintenance as they are a key resource for many higher organisms. However, to be effective biological control agents, able to respond quickly to wherever a pest infestation occurs, then they must be sufficiently abundant and widely distributed. Conservation biocontrol utilising predatory beetles has focussed on the impact of species that overwinter in adjacent field boundaries, although those overwintering within fields are often more abundant. If the abundance and distribution of predatory beetles is to be maximised then further knowledge of their spatial dynamics is required to ensure habitats are arranged appropriately. The spatio-temporal dynamics of boundary and field overwintering species was measured across 64 ha encompassing six fields and for three consecutive years using a grid of 973 pitfall traps. Boundary species were more numerous in spring (May and June) whereas more field species were captured in July. The species composition was comprised of relatively few taxa. Boundary species occurred in small patches that were distributed across the fields in spring, but were only found close to the margins in July. Patches persisted in some locations over two years. Field species occurred in larger patches, spread across particular fields and these were stable within years and to some extent between years. Game-cover strips were attractive to boundary species in the spring and summer and did not effect predator distribution in the adjacent crop.

Agricultural intensification and biodiversity partitioning in European landscapes comparing plants, carabids, and birds

“…One possible explanation are spillover effects from the adjacent non-crop habitats for more mobile taxa, which could lead to variance in the local species composition (Hendrickx et al 2009), as supported by several studies stressing the importance of the surrounding landscape and field margins for the within field carabid community (Denys and Tscharntke 2002, Purtauf et al 2005, Schweiger et al 2005, Hendrickx et al 2007, Bata´ry et al 2008, Smith et al 2008. Likewise, the importance of species-rich field margins and seminatural habitats for within-field species richness has already been shown for many other arthropod taxa depending on body size (ability for mobility; , Schweiger et al 2005, Holland et al 2009) and farmland birds (Vickery et al 2002. For plants, however, the picture could be a little different.…”

Species’ traits influence ground beetle responses to farm and landscape level agricultural intensification in Europe

“…Some ground beetle species are important natural enemies of arable pests and many are a key food resource for birds (Holland et al 2009). As a result, ecosystem services and functions such as biological control and food chain maintenance can be affected if ground beetle community composition changes (Flynn et al 2009;Holland et al 2009;de Bello et al 2010).…”

Migration of coccinellids to alfalfa fields with varying adjacent vegetation in Central Chile

“…The loss of these habitats would also reduce the number of species that could recolonize crops (Concepción et al, 2008). Therefore, field edges may contribute to conservation biological control and must be considered in the management of agricultural landscapes (Landis et al, 2000;Benton et al, 2003;Holland et al, 2004;Pollard and Holland, 2006;Griffiths et al, 2008;Gardiner et al, 2009;Holland et al, 2009). Although these habitat structures have generally been lost in modern intensive agricultural landscapes (Lindborg et al, 2008), some neighboring crops can act also as a source of natural enemies (Grez and Prado, 2000), depending on their composition, structure and permanence, in diverse agricultural landscapes with a mixture of annual and perennial crops.…”