Pollinators communities differ across years and crops (original) (raw)
Related papers
Journal of Applied Entomology, 2022
Pollinating insects provide pollination services to many crop species, including sweet cherry (Prunus avium L.), and this can be delivered by both managed and wild pollinators. Managed pollinators are often used to pollinate a range of fruit crops, but increasingly the role of wild insects is being studied. However, the importance of pollinator species depends on their relative abundance and pollination effectiveness, which depends on their foraging activity and their variability throughout the day. In this study, insect visitors of blossoms were observed in commercial sweet cherry orchards to explore abundance, diversity and pollination foraging behaviour of different insect pollinator groups throughout the day. A total of 1,174 pollinators from 31 different species were recorded visiting cherry blossoms over 2 years, of which 71.0% of total visits were by managed pollinators (western honeybee, Apis mellifera L. and buff‐tailed bumblebee, Bombus terrestris L.) compared to 29.0% by ...
INSECT POLLINATORS AND THEIR CHALLENGES: A REVIEW
2020
Mutualisms between plants and their floral visitors sustain not only plant diversity, but also the diversity of an estimated 350, 000 animal species, mainly various insects, birds and mammals. Wild bees represent the most important group of pollinator insects because they play a key role in agriculture, pollinating almost all crop varieties. However, they are increasingly at risk of local and even global extinction. Climate change and habitat loss are affecting all major aspects of the biology of insects that pollinate plants in both natural and agricultural communities. Understanding network structure and its underlying causes are essential parts of any study of biodiversity and its responses to disturbances, yet it is a conceptual and methodological challenge to address these problems in highly diversified communities with thousands of interactions. Plant-pollinator communities are typically composed of a high number of plant species and an even greater number of pollinator species.
Agricultural and Forest Entomology, 2015
1. Pollination is an important ecosystem service as many agricultural crops such as fruit trees are pollinated by insects. Agricultural intensification, however, has resultedis one of the main drivers resulting in a serious decline of pollinator populations worldwide. 2. In this study pollinator communities were examined in twelve apple orchards surrounded by either homogeneous or heterogeneous landscape in Hungary. Pollinators (honey bees, wild bees, hoverflies) were surveyed in the flowering period of apple trees. Landscape heterogeneity was characterized in circles of 300, 500 and 1000 m radius around each orchard using Shannon's diversity and Shannon's evenness indices. 3. We found that pollination success of apple was only significantly related to the species richness of wild bees, regardless the dominance of honey bees. 4. Diversity and evenness of the surrounding landscape matrix had a marginal positive effect on the species richness of hoverflies at 300m, positive effect on theand species richness of wild bees at 500m radius circle, while evenness of the surrounding landscape and enhanced the abundance of wild bees at 300m and 500m radius circle respectively, while. fFlower resources in the groundcover within the orchards supported honey bees. 5. Therefore maintenance of semi-natural habitats within 500m around apple orchards and permanent groundcover vegetation within the orchards areis highly recommended to enhance both honey bees and wild pollinator communities, and apple production.
Scientific Reports, 2021
Despite Apis mellifera being the most widely managed pollinator to enhance crop production, they are not the most suitable species for highbush blueberries, which possess restrictive floral morphology and require buzz-pollination. Thus, the South American bumblebee Bombus pauloensis is increasingly managed as an alternative species in this crop alongside honeybees. Herein, we evaluated the foraging patterns of the two species, concerning the potential pollen transfer between two blueberry co-blooming cultivars grown under open high tunnels during two seasons considering different colony densities. Both managed pollinators showed different foraging patterns, influenced by the cultivar identity which varied in their floral morphology and nectar production. Our results demonstrate that both species are efficient foragers on highbush blueberry and further suggest that they contribute positively to its pollination in complementary ways: while bumblebees were more effective at the individual level (visited more flowers and carried more pollen), the greater densities of honeybee foragers overcame the difficulties imposed by the flower morphology, irrespective of the stocking rate. This study supports the addition of managed native bumblebees alongside honeybees to enhance pollination services and emphasizes the importance of examining behavioural aspects to optimize management practices in pollinator-dependent crops. Despite honeybees being the most adaptable and widely managed pollinator to enhance crop production 1 , the global stock of Apis mellifera colonies is growing slower than agricultural demands for pollination services 2. With the expansion of areas cultivated with pollinator-dependent crops around the globe 3 , the contribution of wild insects to pollination has been recognized for a wide variety of annual and perennial species 4,5. However, the abundance and diversity of pollinator assemblages vary in different agroecosystems, and growers often rely on managed honeybees for pollination services. Therefore, there has been a growing interest in managing alternative species, such as bees of the genera Osmia, Bombus, and Megachile 6,7. Bumblebees have been proven to be efficient pollinators of greenhouse as well as of outdoor crops 8,9. Furthermore, an integrated approach combining native bees with honeybees can enhance pollination services, due to complementarity in their foraging behaviour 10,11. Highbush blueberry Vaccinium corymbosum, though native to eastern North America, is now cultivated globally. Blueberry global production increased 57% between 2013 and 2018 12. In South America acreage has expanded steadily in the last decade, with Argentina accounting for 20 thousand tons in 2018 13. In these latitudes, southern cultivars are being grown, which were originally developed in the 1980s in Florida where highbush blueberries could not meet their high chilling requirement 14. The numerous cultivars resulting from selective breeding, present varying degrees of pollinator dependency, yet all benefit from cross-pollination and hence two or more cultivars are usually planted in adjacent rows 15,16. Also, blueberry cultivars exhibit diverse floral morphologies that may affect visitation rates and behaviour of pollinators 17. Blueberry flowers are small, with urceolate corollas which limit the access of visitors to the basal nectaries. In addition to its accessibility, intraspecific variability of the quantity and quality of nectar could modify the attractiveness of different cultivars to bees. Blueberry flowers are also visited for their pollen. Their poricidal dehiscent anthers require buzz-pollination,
Pollinator communities in strawberry crops – variation at multiple spatial scales
Predicting potential pollination services of wild bees in crops requires knowledge of their spatial distribution within fields. Field margins can serve as nesting and foraging habitats for wild bees and can be a source of pollinators. Regional differences in pollinator community composition may affect this spill-over of bees. We studied how regional and local differences affect the spatial distribution of wild bee species richness , activity-density and body size in crop fields. We sampled bees both from the field centre and at two different types of semi-natural field margins, grass strips and hedges, in 12 strawberry fields. The fields were distributed over four regions in Northern Europe, representing an almost 1100 km long north-south gradient. Even over this gradient, daytime temperatures during sampling did not differ significantly between regions and did therefore probably not impact bee activity. Bee species richness was higher in field margins compared with field centres independent of field size. However, there was no difference between centre and margin in body-size or activity-density. In contrast, bee activity-density increased towards the southern regions, whereas the mean body size increased towards the north. In conclusion, our study revealed a general pattern across European regions of bee diversity, but not activity-density, declining towards the field interior which suggests that the benefits of functional diversity of pollinators may be difficult to achieve through spill-over effects from margins to crop. We also identified dissimilar regional patterns in bee diversity and activity-density, which should be taken into account in conservation management.
Do Patches of Flowering Plants Enhance Insect Pollinators in Apple Orchards?
Insects
Apples depend on insect pollination but intensification of agriculture jeopardizes pollination services in agroecosystems. Concerns about the dependency of crop pollination exclusively on honey bees increase the interest in agricultural practices that safeguard wild pollinators in agroecosystems. The purpose of the study was to assess the potential of floral resource provision in apple orchards to enhance the conservation of hymenopterous pollinating insects and potentially the pollination service to the crop. For this reason, flowering plant mixtures sown in patches inside apple orchards were tested against wild plant patches. Pollinator taxa recorded on the sown and wild plant patches were honey bees, wild bees (Andrena, Anthophora, Eucera, Halictus, Lasioglossum, Megachilidae on both; Systropha only on wild plants; Bombus, Hylaeus, Sphecodes, Nomada, Xylocopa only on sown mixture), syrphids, bee flies. The most abundant pollinator of apple was A. mellifera but wild bees were also...
An Assessment of Non-Apis Bees as Fruit and Vegetable Crop Pollinators
2011
Declines in pollinators around the globe, notably the loss of honey bees (Apis mellifera L.) to Colony Collapse Disorder, coupled with a dearth of quantitative data on non-Apis bee pollinators, led to this dissertation research, which documents the role of non-Apis bees in crop pollination in southwest Virginia. Major findings of this first study of its kind in the region were that non-Apis bees provided the majority of pollination—measured by visitation—for several economically important entomophilous crops (apple, blueberry, caneberry, and cucurbits); diverse bee populations may be helping to stabilize pollination service (105 species on crop flowers); landscape factors were better predictors of non-Apis crop pollination service than farm management factors or overall bee diversity; and non-Apis bees in the genera Andrena, Bombus, and Osmia were as constant as honey bees when foraging on apple. Non-Apis, primarily native, bees made up between 68 % (in caneberries) and 83 % (in cuc...