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Providing evidence to improve practice

Individual study: Increasing syrphid fly diversity and density in sown flower strips within simple vs. complex landscapes

Published source details

Haenke S., Scheid B., Schaefer M., Tscharntke T. & Thies C. (2009) Increasing syrphid fly diversity and density in sown flower strips within simple vs. complex landscapes. Journal of Applied Ecology, 46, 1106-1114


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Create uncultivated margins around intensive arable or pasture fields Farmland Conservation

A replicated, controlled study in summer 2006 in north Germany (Haenke et al. 2009) found that species richness and abundance of hoverflies (Syrphidae) during the wheat peak-ripening stage was higher in naturally developed grass strips (3 m wide, seven sites) than in wheat-wheat boundaries (seven sites) and within the wheat fields adjacent to the margins (seven sites), but lower than in sown flower strips (seven sites each). Hoverfly density and species richness increased with increasing amount of arable land at smaller scales (0.5 and 1 km around site) but not at larger scales (2 and 4 km). This was true for all hoverflies and all aphid-eating hoverfly species. Margins were located along a gradient of different habitat complexities in the surrounding landscape, ranging from 30% to 100% arable land. Hoverflies were captured by sweep netting (one sweep per footstep) along 100 m transects.

Plant nectar flower mixture/wildflower strips Farmland Conservation

A replicated, controlled study in June and July 2006 in north Germany (Haenke et al. 2009) found more hoverflies (Syrphidae) and hoverfly species in broad (12-25m wide) and narrow (3-6 m) sown wildflower strips (7 sites each) than in grassy margins (3 m-wide, 7 sites), wheat-wheat boundaries (7 sites) and within wheat fields adjacent to the margins (7 sites). Hoverfly density and species richness (total hoverflies and aphid-eating hoverflies) also increased with increasing amount of arable land around the site at smaller scales (0.5 and 1 km) but not at larger scales (2 and 4 km). Margins were located along a gradient of habitat complexities in the surrounding landscape, ranging from 30% to 100% arable land. Hoverflies were sampled by sweep netting (one sweep per footstep) along 100 m transects.