Manipulating field margins to increase predation intensity in fields of winter wheat (Triticum aestivum)

摘要: The effectiveness of natural enemies to control pests can be enhanced through habitat manipulation. However, due the differences in their ecology, generalist and specialist species may respond differently same Moreover, interactions among (i.e. cannibalism, intraguild predation, hyperparasitism) complicate assumption that a higher density would increase level biological control. We investigated enemy guild composition predation rate along flower vs. grass margins at edge winter wheat (Triticum aestivum) fields Denmark. Natural were sampled by pitfall trapping suction sampling; intensity was measured using two different sentinel prey methods: artificial caterpillars made plasticine, aphid colonies. Specialist responded margin types: specialists (mostly parasitic wasps) attracted margins, while generalists (ground beetles, rove beetles spiders) more active margins. number attacked significantly greater (mean = 48.9%, SD = 24.3) than (mean = 30.7%, SD = 17.4). found significant positive relationship between chewing insects, and activity for large (≥15 mm) ground beetles. Predation aphids did not vary relation type. Our results suggest flowering beneficial canopy-active enemies, but grassy are useful ground-active predators.