Flowering areas enhance insect pollinators and biological control agents in wheat intensive agro‐ecosystems

Abstract

Abstract This 4‐year study (2018–2021) aimed at investigating the effects of flowering areas inserted at the margin of soft wheat fields (Triticum aestivum L.) in comparison with spontaneous field margins. The action formed part of a multidisciplinary initiative promoted by the Barilla food company, aimed at promoting the sustainable production of soft wheat. Specific aims were to study the effects of flowering areas on (i) the abundance and species richness of insect pollinators, including wild bees, syrphids and butterflies; (ii) the levels of wheat aphid and bug infestations and (iii) the assemblages of biological control agents of aphids (coccinellids and aphid mummies as a result of parasitization). Insect surveys were carried out on 61 wheat‐growing farms located in Northern Italy. Insect pollinators were sampled on all farms, whereas wheat aphids, wheat bugs and aphid biological control agents were investigated in a sub‐sample of 20 farms. Results generally indicated a positive impact of flowering areas on multiple taxa in comparison with spontaneous field margins. The abundance of pollinators and coccinellids was significantly enhanced by the flowering areas. Aphid mummies showed an interaction between strategies and distances with more mummies at 5 m in wheat plots close to flowering areas and at 50 m in the plots close to spontaneous field margin (control). Flowering areas were validated as an important tool for promoting beneficial taxa in agro‐ecosystems. However, the successful establishment of this ecological infrastructure was suggested to rely on several factors, which included both the selection of suitable flowering plant species and the implementation of appropriate management practices.