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Plant and pollinator diversity have declined concurrently in Europe in the last half century. We studied plant–bumblebee food webs to understand the effects of two agri-environmental schemes (AES, organic farming and environmentally-friendly management practice) vs. conventional farming as control group, landscape structure (heterogeneous vs. homogeneous landscapes) and seasonality (June, July, and August) interactions using Estonian AES monitoring data. In the summer of 2014, we observed foraging bumblebees (20 species) on 64 farms that varied in agricultural management and landscape structure, yielding a total of 2303 flower visits on 76 plant species. We found that both management practice and landscape structure influenced the generality (redundancy in the use of flower resources) of food webs. In homogeneous landscapes, environmentally-friendly management practices, including restrictions on the application of glyphosates, enhancement of bumblebee habitats, such as permanent grassland field margins, the allocation of a minimum of 15% of arable land (including rotational grasslands) to legumes, contributed to a higher number of visited plant species (generality) in July, whereas organic farming did so in August. Therefore, both environmentally-friendly and organic management practices are needed to support plant–bumblebee food webs in agricultural landscapes. Food web generality and diversity (Shannon index) are affected by a significant interaction between landscape structure and seasonality: food web diversity varied in homogeneous landscapes between the three different survey months, whereas food webs were more diverse in heterogeneous landscapes. We did not find any significant interaction effect of management, landscape structure and seasonality on linkage density and vulnerability. A full list of the most visited plant species by bumblebees based on species-specific flower visitation was also assembled. In homogeneous landscapes, resource limitation is an issue for bumblebees in certain time periods. For supporting bumblebees in the agricultural landscapes, avoiding resource limitation is important and this can be secured with a combination of AES management practices.

In many parts of the world, farmland pollinators decreased significantly during the last half of the 20th century mainly due to land‐use changes and agricultural intensification. We studied the effect of different typical crop rotations and agri‐environment schemes (AES) on bumblebee diversity in Estonia. We compared species abundances between four crop rotation types (cereal rollover [no change from 1 year to the next], cereal to mass‐flowering crops [hereafter MFC], MFC rollover and MFC to cereal fields) where all counts were conducted in the second year and in three farming types (conventional farming, organic farming and environmentally friendly management). We surveyed bumblebees and flower cover along 401 field margins in five consecutive years and recorded 20 species and more than 6,000 individuals. Abundances of long‐tongued and threatened bumblebee species were higher at the field margins of cereal rollover fields than for the other three crop rotation types. In addition, cereal rollover field margins had higher abundances of medium colony species, generalists and forest‐scrub species than MFC rollover and MFC to cereal or cereal to MFC field margins. Bumblebee species richness was higher at the field margins of both AES types than those of conventional farming. However, in general, the strongest driver of bumblebee presence was flower cover. Higher bumblebee abundances in cereal rollover field margins were probably owing to a concentration effect there and/or a dilution effect into MFC fields. Both AES schemes supported increasing flower cover in field margins and thereby diversity of bumblebees, indicating positive AES impacts upon wild pollinators. Synthesis and applications. Crop rotation and agri‐environment schemes determine bumblebee richness and abundance via the availability of flower resources, but crop rotation constrains bumblebees differently based on their traits. Therefore, future agri‐environmental policy should account for these management options. Crop rotation could be a simple, but efficient solution to increase the biodiversity of agricultural landscapes.

Farmland biodiversity dramatically declined in Europe during the 20th century. Agri-environment schemes (AES) were introduced in the late 1980s in European Union countries as a solution to combat biodiversity decline. We examined the effectiveness of AES in enhancing biodiversity in a new EU member country (Estonia) over the period of 2010–2012. We compared species numbers and abundance of bumblebees and birds, plus cover of flowers, between three farming systems in two regions of Estonia. Farm types included conventional and two under AES (organic and a less strict environmentally friendly management agreement). Environmentally friendly management practices in Estonia include diversified crop rotations, at least 15% of arable land (including rotational grasslands) under legumes, permanent grassland strips, protection of landscape elements, reduced applications of agrochemicals, etc. The two selected regions (North and South) differed in landscape structure, soil types and crop yields. Flower cover and bird species richness and abundance without the dominant species (skylark) were higher on organic farms. Bumblebee species richness was significantly higher under both types of AES than under conventional farming. Flower cover, abundance and species richness of bumblebees and birds were significantly higher in the more heterogeneous landscapes of Southern Estonia. Environmentally friendly management may be a viable alternative to organic farming for a widely accepted, simple but large-scale greening of agricultural landscapes.

Sublethal effects of pesticides in insects can be observed through physiological changes, which are commonly estimated by metabolic rate and respiratory patterns, more precisely by the patterns of discontinuous gas-exchange (DGE) cycles. The aim of the present research was to study the effect of some low concentrations of Fastac 50 EC on the cycles of CO2 release and respiratory water loss rates (WLR) in bumble bee Bombus terrestris L. foragers. Bumble bees were dipped into 0.004% and 0.002% Fastac 50 EC solution. Flow-through respirometry was used to record the respiration and WLR 3 h before and after the treatment. The respirometry was combined with infrared actography to enable simultaneous recording of abdominal movements. Our results show that Fastac 50 EC has an after-effect on bumble bee respiratory rhythms and muscle activity but does not affect WLR. Treatment with 0.004% Fastac 50 EC solution resulted in disappearance of the respiration cycles; also the lifespan of treated bumble bees was significantly shorter. Treatment with 0.002% Fastac 50 EC solution had no significant effect on respiration patterns or longevity. We found no evidence for the DGE cycles functioning as a water saving mechanism. 2012 Elsevier Ltd. All rights reserved.

BACKGROUND: Cruciferous oil-bearing crops have gained in importance worldwide. The expansion of the growing area of these crops has caused a proliferation of pests. Exposure to organophosphate, carbamate and pyrethroid insecticides has been associated with bee poisoning in food crops. This study examines the repellent effect of alpha-cypermethrin on the number of foraging honey bees, Apis mellifera L., on fields of spring oilseed rape, Brassica napus L. var. oleifera. RESULTS: The first experiment was conducted on differently sprayed 10m 2 experimental plots where alpha-cypermethrin was applied at different times. Another experiment was conducted on a 4 ha seed production field divided into two parts: one part was treated with alpha-cypermethrin and the other was not treated with this insecticide. The results show that there was no difference in the number of honey bees between alpha-cypermethrin-treated and untreated patches. The result persisted through three observation years, regardless of varying flower and honey bee densities. CONCLUSION: No repellent effect of the insecticide on honey bees was found even 24 h after spraying. The density of oilseed rape flowers most likely played a major role in choosing the foraging area.

A large proportion of European biodiversity today depends on habitat provided by low‐intensity farming practices, yet this resource is declining as European agriculture intensifies. Within the European Union, particularly the central and eastern new member states have retained relatively large areas of species‐rich farmland, but despite increased investment in nature conservation here in recent years, farmland biodiversity trends appear to be worsening. Although the high biodiversity value of Central and Eastern European farmland has long been reported, the amount of research in the international literature focused on farmland biodiversity in this region remains comparatively tiny, and measures within the EU Common Agricultural Policy are relatively poorly adapted to support it. In this opinion study, we argue that, 10 years after the accession of the first eastern EU new member states, the continued under‐representation of the low‐intensity farmland in Central and Eastern Europe in the international literature and EU policy is impeding the development of sound, evidence‐based conservation interventions. The biodiversity benefits for Europe of existing low‐intensity farmland, particularly in the central and eastern states, should be harnessed before they are lost. Instead of waiting for species‐rich farmland to further decline, targeted research and monitoring to create locally appropriate conservation strategies for these habitats is needed now., Volkswagen Foundation

As a major mass-flowering crop producing an abundance of nectar and pollen, oilseed rape is very attractive to honey bees, bumblebees and solitary bees. It provides a food resource of considerable value in sustaining bee populations in agroecosystems at a time when bees are in decline. Although the flowers are self-fertile, they are entomophilous, and pollination studies, both in the glasshouse and in the field, suggest that bee foraging activities on the crop have many beneficial effects for the grower, including improving both the quantity and quality of the seed produced. However, bees foraging on the crop are vulnerable to the effects of insecticides, mostly pyrethroids applied to the crop, particularly when these are applied during flowering to control inflorescence pests. Effects may be lethal or sub-lethal; the latter have been little studied but there is growing evidence that insecticides affect many aspects of bee behaviour and physiology, such as division of labour, foraging and orientation, reproduction and respiration. Husbandry practices on the crop must therefore seek to minimise the use of insecticides on the crop, particularly during flowering, in order to sustain and not diminish bee populations foraging on the crop. Bees may even have a role in integrated pest management strategies incorporating biocontrol through their capacity to vector entomopathogenic fungal spores to the flowering canopy of oilseed rape to kill inflorescence pests.