Hedgerows surrounding organic apple orchards in north‐west Spain: potential to conserve beneficial insects

Abstract

1 Flowering plant species in hedgerows may be food sources for beneficial insects and therefore play a role in biodiversity conservation and agroecosystem functioning. Research was conducted in eight organic cider-apple orchards in Asturias (northwest Spain) aiming to (i) identify the native flowering plants in the surrounding hedgerows and (ii) assess the attractiveness of those flowers for beneficial insects, such as pollinators and natural enemies of pests. 2 A total of 7745 flowers belonging to 63 plant species were recorded in the hedgerows from May to September 2012. Flower abundance and species richness decreased as the season progressed. Orchard differences were observed for plant species richness but not for the total number of flowers in the hedgerows, likely as a result of similar management among orchards. 3 Hymenoptera pollinators (honey bees, bumblebees and wild bees) accounted for 37.8% of the total insects recorded visiting flowers, whereas predatory hoverflies (14.9%) were the dominant natural enemies. 4 The attractiveness for insects was assessed for 21 of the flowering plant species identified in the hedgerows. Flowering plants differed in the number of taxa that they attracted and in their attractiveness for particular insect groups and for insects as a whole. 5 The present study described the floral composition of the hedgerows that surround apple orchards and identified the local floral resources that could provide benefits for farmers by improving ecosystem services of pollination and biological control of pests.

Agroecology and Ecological Intensification. A Discussion from a Metabolic Point of View

“…This percentage is similar to that obtained in different case studies of pest management under Mediterranean agroclimatic conditions [44,45]. The planting of the equivalent of a 100 m by 5 m hedge per agricultural hectare is very ambitious in Spain, given the scarcity of areas of natural vegetation in these zones.…”

The attractiveness of flowering herbaceous plants to bees (Hymenoptera: Apoidea) and hoverflies (Diptera: Syrphidae) in agro‐ecosystems of Central Spain

“…As a result of a lack of practical information on attractiveness and management of beneficial plants in Spain (Miñarro & Prida, ), the implementation of known beneficial plants within Spanish agro‐ecosystems is still limited. Therefore, the main objective of the present study was to identify the most appropriate plant species for improving the habitat for pollinators in agro‐ecosystems of Central Spain, where a preliminary selection of plants prioritized native or naturalized (Tuell et al , ; Morandin & Kremen, ) and not invasive (Stout & Morales, ) plants.…”

Complementarity and redundancy in the functional niche of cider apple pollinators

“…In addition, as the cultural tolerance of growers to pests is high in general because aesthetic damage is of no importance for cider apples, the use of fungicides and insecticides is not common. These orchards are embedded in a highly variegated landscape and are typically surrounded by natural woody vegetation (Miñarro and Prida 2013;García et al 2018). The low degree of agricultural intensification in these orchards and the surrounding landscape thus allow for high animal diversity within orchards, including natural enemies (Miñarro et al 2011;García et al 2018).…”

“…As a final remark, we would highlight that, as has been shown for other crops (Garibaldi et al 2013;Rader et al 2016), both wild insects and honeybees are probably necessary to optimise the global service of pollination in cider apple. We encourage, therefore, actions to promote wild pollinator diversity through habitat management (floral cover in orchards and surrounding woody hedgerows; Miñarro and Prida 2013;Dicks et al 2016;Campbell et al 2017), in parallel with honeybee management regimes that are non-harmful for wild species (Geldmann and González-Varo 2018).…”