Managing Floral Resources in Apple Orchards for Pest Control: Ideas, Experiences and Future Directions

Abstract

Functional biodiversity is of fundamental importance for pest control. Many natural enemies rely on floral resources to complete their life cycle. Farmers need to ensure the availability of suitable and sufficient floral biodiversity. This review summarizes 66 studies on the management of floral biodiversity in apple orchards, published since 1986. Approaches followed different degrees of intervention: short-term practices (mowing regime and weed maintenance, cover crops), establishment of durable ecological infrastructures (perennial flower strips, hedgerows) and re-design of the crop system (intercropping, agroforestry). Although short-term practices did not always target the nutrition of natural enemies by flowering plants, living conditions for them (alternative prey, provision of habitat) were often improved. Perennial flower strips reliably enhanced natural enemies and techniques for their introduction continuously developed. Resident natural enemies and their impact in pest control reacted positively to the introduction of a more diversified vegetation, whereas the response of very mobile organisms was often not directly linked to the measures taken. A careful selection and management of plants with particular traits exploitable by most natural enemies emerged as a key-point for success. Now the elaborated design of such measures needs to be adopted by stakeholders and policy makers to encourage farmers to implement these measures in their orchards.

Management to Promote Flowering Understoreys Benefits Natural Enemy Diversity, Aphid Suppression and Income in an Agroforestry System

“…We found that flowering understoreys increased natural enemy abundance in apple trees early in the season, reduced aphid colony density, and reduced the number of apples lost to aphid damage, which is supported by previous research of flower strips in insecticidefree apple orchards [53,54]. However, to our knowledge, this study is the first to report lower apple damage at harvest and, as a consequence, financial benefits of flowering strips for apple production.…”

Predatory arthropod community composition in apple orchards: Orchard management, landscape structure and sampling method

“…The hybotid fauna was surprisingly rich in these apple orchards, and we found one new species for Sweden ( P. leucocephalus ) and 17 of 86 Platypalpus species recorded in Sweden. The reason why hybotids are common in apple orchards is not clear, even though our study shows the importance of flowering plant cover within orchards (see also Cahenzli et al., 2019; Herz et al., 2019), but it may be that the access of potential prey and the relatively open habitat in the orchards are important. Hybotids are a group of dipterans that are strictly predatory, running on the leaves or making short flying expeditions to catch small insects, such as other dipterans, thrips and psyllids (Chvála, 1975).…”

A Growers’ Perspective on Crop Pollination and Measures to Manage the Pollination Service of Wild Pollinators in Sweet Cherry Cultivation

“…Opinion on this issue was clearly divided. Based on the literature, the majority of the research on increasing floral resources in or around fruit orchards by means of an extensive mowing regime, flower strips or hedgerows has a positive effect on both insect predators [28,29] and pollinating insects [10,25,26,[30][31][32]. Nevertheless, some studies have concluded that there is no positive effect on insect pollinators in fruit orchards during full bloom [11,18].…”