LAUSR

Plant reproductive success is often the outcome of mutualistic and antagonistic plant–animal interactions, which can be moderated by landscape composition. Studies addressing single plant–animal interactions are common, but studies simultaneously considering multiple plant–animal interactions in a landscape context are still scarce. We selectively excluded flower-visiting insects on phytometer plants and quantified how mutualistic and antagonistic interactions shaped the reproductive success of a common annual plant, wild mustard (Sinapis arvensis). Floral herbivory by larvae of rape pollen beetles (Meligethes spp.) strongly reduced fruit production, but could be minimized by insecticide application. Total seed production (the product of fruit production and seeds per fruit) strongly increased with pollinator visitation. On average, pollinator access to plants enhanced seed numbers by 754%. Insecticide treatment almost redoubled this number. The landscape composition (proportion of semi-natural habitats in 1000 m radius) surrounding phytometer plants did not affect plant–animal interactions, presumably due to the high dispersal ability of both the pollen beetles and the major pollinators (syrphid flies, bumblebees). In conclusion, pest control increased reproductive success only in the case of sufficient pollination.