A growers’ perspective on crop pollination and measures to manage the pollination service of wild pollinators in sweet cherry cultivation

Recent declines in insect pollinators and the increasing dependence on insect pollination in agriculture present major challenges to ensuring future food production. As part of the effort to deal with this challenge, there is a pressing need to understand growers' perceptions with regard to pollinator diversity and crop pollination management. At present, many growers are dependent on domesticated honey bees (Apis mellifera), however, targeted management strategies involving naturally occurring pollinator species might be necessary to ensure future crop pollination. In this study we used semi-structured interviews to explore growers' knowledge about crop pollination and current practices to manage insect pollination in sweet cherry cultivation. Our findings suggest that growers have a clear understanding of the importance of pollination and its determining factors. However, with respect to their current pollination management, growers depend mainly on honey bees and only apply measures to enhance wild pollinator communities to a limited extent. Our study highlights the gap between the growers' perception of the contribution of wild pollinators to crop pollination, and their efforts to manage these species. We conclude that this is due to a lack of communication of recent scientific findings on the contribution of pollinating insects to crop pollination through the information channels that are being used by growers today. It is therefore crucial that scientists, government and other stakeholders work together with growers and communicate scientific evidence as well as practical guidelines to growers

Effects of imidacloprid in combination with λ-cyhalothrin on the model pollinator Bombus terrestris at different levels of complexity

Keywords: bumblebee, Bombus terrestris, neonicotinoids, pyrethroids, toxicity, sublethal effects and risk assessmen

Larval oral exposure to thiacloprid : dose-response toxicity testing in solitary bees, Osmia spp. (Hymenoptera: Megachilidae)

Risk assessment of pesticides involves ecotoxicological testing. In case pesticide exposure to bees is likely, toxicity tests are performed with honey bees (Apis mellifera), with a tiered approach, for which validated and internationally accepted test protocols exist. However, concerns have grown regarding the protection of non-Apis bees [bumble bees (Bombus spp.), solitary and stingless bees], given their different life cycles and therefore distinct exposure routes. Larvae of solitary bees of the genus Osmia feed on unprocessed pollen during development, yet no toxicity test protocol is internationally accepted or validated to assess the impact of pesticide exposure during this stage of their life cycle. Therefore, the purpose of this study is to further validate a test protocol with two solitary bee species (O. cornuta and O. bicornis) to assess lethal and sublethal effects of pesticide exposure on larval development. Larvae were exposed to thiacloprid (neonicotinoid insecticide) mixed in a new, artificial pollen provision. Both lethal (developmental and winter mortality) and sublethal endpoints (larval development time, pollen provision consumption, cocoon weight, emergence time and adult longevity) were recorded. Effects of lower, more environmentally realistic doses were only reflected in sublethal endpoints. In both bee species, thiacloprid treatment was associated with increased developmental mortality and larval development time, and decreased pollen provision consumption and cocoon weight. The test protocol proved valid and robust and showed that for higher doses of thiacloprid the acute endpoint (larval mortality) is sufficient. In addition, new insights needed to develop a standardized test protocol were acquired, such as testing of a positive control for the first time and selection of male and female individuals at egg level

CropPol: a dynamic, open and global database on crop pollination

Seventy five percent of the world's food crops benefit from insect pollination. Hence, there has been increased interest in how global change drivers impact this critical ecosystem service. Because standardized data on crop pollination are rarely available, we are limited in our capacity to understand the variation in pollination benefits to crop yield, as well as to anticipate changes in this service, develop predictions, and inform management actions. Here, we present CropPol, a dynamic, open and global database on crop pollination. It contains measurements recorded from 202 crop studies, covering 3,394 field observations, 2,552 yield measurements (i.e. berry weight, number of fruits and kg per hectare, among others), and 47,752 insect records from 48 commercial crops distributed around the globe. CropPol comprises 32 of the 87 leading global crops and commodities that are pollinator dependent. Malus domestica is the most represented crop (32 studies), followed by Brassica napus (22 studies), Vaccinium corymbosum (13 studies), and Citrullus lanatus (12 studies). The most abundant pollinator guilds recorded are honey bees (34.22% counts), bumblebees (19.19%), flies other than Syrphidae and Bombyliidae (13.18%), other wild bees (13.13%), beetles (10.97%), Syrphidae (4.87%), and Bombyliidae (0.05%). Locations comprise 34 countries distributed among Europe (76 studies), Northern America (60), Latin America and the Caribbean (29), Asia (20), Oceania (10), and Africa (7). Sampling spans three decades and is concentrated on 2001-05 (21 studies), 2006-10 (40), 2011-15 (88), and 2016-20 (50). This is the most comprehensive open global data set on measurements of crop flower visitors, crop pollinators and pollination to date, and we encourage researchers to add more datasets to this database in the future. This data set is released for non-commercial use only. Credits should be given to this paper (i.e., proper citation), and the products generated with this database should be shared under the same license terms (CC BY-NC-SA). This article is protected by copyright. All rights reserved

Pollinator-flower interactions in gardens during the covid 19 pandemic lockdown of 2020

During the main COVID-19 global pandemic lockdown period of 2020 an impromptu set of pollination ecologists came together via social media and personal contacts to carry out standardised surveys of the flower visits and plants in gardens. The surveys involved 67 rural, suburban and urban gardens, of various sizes, ranging from 61.18° North in Norway to 37.96° South in Australia, resulting in a data set of 25,174 rows, with each row being a unique interaction record for that date/site/plant species, and comprising almost 47,000 visits to flowers, as well as records of flowers that were not visited by pollinators, for over 1,000 species and varieties belonging to more than 460 genera and 96 plant families. The more than 650 species of flower visitors belong to 12 orders of invertebrates and four of vertebrates. In this first publication from the project, we present a brief description of the data and make it freely available for any researchers to use in the future, the only restriction being that they cite this paper in the first instance. The data generated from these global surveys will provide scientific evidence to help us understand the role that private gardens (in urban, rural and suburban areas) can play in conserving insect pollinators and identify management actions to enhance their potential

Cardboard nesting cavities may promote the development of Osmia cornuta and reduce infestation of kleptoparasitic mites

Mason bees (Osmia spp.) are receiving increasing attention as they are very effective pollinators of multiple crops. However, different bee‐associated kleptoparasites are known which can be detrimental to the development of the bees’ offspring. To date, clear evidence‐based guidelines to control these kleptoparasites are lacking for growers. This study investigates whether different types of artificial nesting materials—cardboard tubes and wooden grooved boards—influence the development of the European orchard bee (Osmia cornuta) as well as the infestation rate of kleptoparasitic mites in the bees’ nest. This preliminary study provides insight that cardboard tubes reduce the infestation rate of mites by 81.8% and as such promote successful development of the European orchard bee by 15.5%. Using cardboard tubes over wooden grooved boards should be advised to growers as an effective management strategy to avoid infestation of kleptoparasitic mites and to enhance successful bee development

Increasing wild bee richness and abundance on sequentially flowering cultivars of a pollinator-dependent crop

Many insects have a crucial role as pollinators in both natural ecosystems and agricultural systems. Reports of declining pollinator populations highlight the question how we can support them. Next to semi-natural habitat, different land use types can provide resources for pollinators. However, whether and how different cultivars of pollinator-dependent crops support pollinator populations has not been studied to date. This preliminary study investigated how the abundance of Osmia cornuta and the richness, abundance and community composition of wild pollinators (i.e. wild bees and hover flies) fluctuates throughout the bloom period of three sequentially flowering sweet cherry (Prunus avium) cultivars. Total pollinator richness and abundance increased throughout the bloom period of the different cherry cultivars. This increase was driven by an increase of wild bee richness and abundance, coupled with a decrease of nest-searching bees. The abundance of O. cornuta was found to in-crease throughout the bloom period. Furthermore, the composition of the pollinator community was significantly different across the different cultivars. Results of this preliminary study reflect the dynamics of wild bee emergence, mating and nest construction, which results in an increase in pollinator diversity and abundance in spring. This study also provides the first evidence that sequentially flowering cultivars of a pollinator-dependent crop can provide complementary floral resources that support complementary pollinator communities. Given the importance of wild pollinators for crop pollination, these results have implications for crop production and pollinator persistence in agricultural landscapes

Pollinator diversity, floral resources and semi-natural habitat, instead of honey bees and intensive agriculture, enhance pollination service to sweet cherry

Declines of pollinator diversity are causing concern about pollination service security for agriculture and natural ecosystems. Landscape composition has been found to regulate the diversity of pollinator communities and their corresponding pollination services in agricultural fields, with previous research concluding positive effects of semi-natural habitat or negative effects of intensive agriculture. In our study we assessed pollinator diversity and pollination services in sweet cherry orchards (Prunus avium) along two non-collinear, independent gradients of semi-natural habitat and intensive agriculture (i.e. percentage of cultivated land) around the orchards. The influence of floral resources in the herb layer in the orchards was also assessed. Our results show that semi-natural habitat clearly support pollinator species richness and wild pollinator abundance. Next to semi-natural habitat, flowering plants in the herb layer of the orchards was an additional driver of pollinator diversity in sweet cherry orchards. Although approximately 80% of all flower visitors were managed honey bees, fruit set of sweet cherry was only clearly linked to pollinator species richness and wild pollinator abundance. Management strategies to support sweet cherry production might include the creation of semi-natural habitat around orchards and the promotion of floral resources in the orchard's herb layer to support pollinating insects