Cocoon orientation in the nests of red mason bees (Osmia bicornis) is affected by cocoon size and available space

Proper orientation of cocoons in linearly structured nests can be crucial for the survival of hatching bees. Nevertheless, misoriented cocoons appear in nature in notable proportions. A detailed analysis of sex, space available for cocoon spinning, cocoon size, and nest diameter in the red mason bee (Osmia bicornis) showed that smaller males are more prone to misorientation than larger females. Generally, smaller individuals of both sexes are more often misoriented because smaller larvae disregard the direction of the entrance during cocoon construction. Moreover, cocoons in stems of smaller diameter are less often misoriented than bees in wider nests. Our results suggest that cocoon size and available space are the most important traits affecting cocoon orientation

Orientation inside linear nests by male and female Osmia bicornis (Megachilidae)

Numerous species of solitary bees and wasps build linear nests with only one entrance. Developing insects must orient themselves inside their nest to choose the correct direction in which to emerge. Misorientation and chewing towards the dead end of the nest can result in significant mortality. Most insects position themselves towards the nest entrance during cocoon construction; however, some individuals are misoriented. We tested whether imagines can examine and possibly correct their orientation after emerging from their cocoons. Males were usually able to correct their misoriented position based on the shape of the cell wall and emerged through the correct entrance, whereas most females pursued the direction that they faced in their cocoons. We suggest that there can be more than one time point during development when bees can control their position in relation to the nest entrance and that the importance of these time points varies between sexes

Greenhouse bumblebees (Bombus terrestris) spread their genes into the wild

Bumblebees (Bombus spp.) are commonly used for greenhouse pollination of tomatoes and other crop plants. The colonies used for this purpose are provided by commercial bumblebee breeders, which by now operate at a professional company level. As a result of this practice commercially bred bumblebee colonies are transported and used over large distances and national borders, introducing subspecies into non-endemic regions. The question whether and to what extends gene flow between such managed greenhouse and wild bumblebee populations exists, so far has not been addressed. Here we used samples from three greenhouses in Poland and the surrounding populations to address this question. Using microsatellite DNA data we found strong genetic introgression from the sampled greenhouse populations into the adjacent populations. Depending on the analysed population, the number of individuals assigned to the greenhouse populations ranged from 0.08 to 0.47. We also found that more distant populations were much less affected by genetic introgression from the greenhouses

Antioxidant Capacity Determination of Hungarian-, Slovak-, and Polish-Origin Goldenrod Honeys

The goldenrod (Solidago) species are flowering plants that produce nectar and can be the sources of unifloral honeys. S. canadensis and S. gigantea are native to North America and invasive in several European countries, while S. virgaurea is native to Europe. The aim of this work was to determine and compare the antioxidant capacity of goldenrod honeys collected in three central European countries (Hungary, Poland, and Slovakia), from three locations within each country. The botanical origin of each honey sample was checked with melissopalynological analysis. Color intensity was determined using the Pfund scale. The antioxidant activity was determined with different spectrophotometric methods (DPPH, ABTS, and FRAP). The content of total polyphenols, flavonoids, and phenolic acids was quantified using spectrophotometric methods. The highest radical-scavenging activity was identified for Hungarian samples with all three antioxidant capacity assays. Medium antioxidant activity was described for Slovak samples. The DPPH and ABTS assays discriminated Polish honeys with the lowest antioxidant activity. The highest flavonoid and phenolic acid content was detected in Hungarian and Slovak honeys, while the lowest values were measured in Polish samples. Our study shows that the antioxidant capacity of unifloral goldenrod honeys can be different in various countries of origin, correlating with color intensity and polyphenol content

A critical analysis of the potential for EU Common Agricultural Policy measures to support wild pollinators on farmland

1. Agricultural intensification and associated loss of high‐quality habitats are key drivers of insect pollinator declines. With the aim of decreasing the environmental impact of agriculture, the 2014 EU Common Agricultural Policy (CAP) defined a set of habitat and landscape features (Ecological Focus Areas: EFAs) farmers could select from as a requirement to receive basic farm payments. To inform the post‐2020 CAP, we performed a European‐scale evaluation to determine how different EFA options vary in their potential to support insect pollinators under standard and pollinator‐friendly management, as well as the extent of farmer uptake. 2. A structured Delphi elicitation process engaged 22 experts from 18 European countries to evaluate EFAs options. By considering life cycle requirements of key pollinating taxa (i.e. bumble bees, solitary bees and hoverflies), each option was evaluated for its potential to provide forage, bee nesting sites and hoverfly larval resources. 3. EFA options varied substantially in the resources they were perceived to provide and their effectiveness varied geographically and temporally. For example, field margins provide relatively good forage throughout the season in Southern and Eastern Europe but lacked early‐season forage in Northern and Western Europe. Under standard management, no single EFA option achieved high scores across resource categories and a scarcity of late season forage was perceived. 4. Experts identified substantial opportunities to improve habitat quality by adopting pollinator‐friendly management. Improving management alone was, however, unlikely to ensure that all pollinator resource requirements were met. Our analyses suggest that a combination of poor management, differences in the inherent pollinator habitat quality and uptake bias towards catch crops and nitrogen‐fixing crops severely limit the potential of EFAs to support pollinators in European agricultural landscapes. 5. Policy Implications. To conserve pollinators and help protect pollination services, our expert elicitation highlights the need to create a variety of interconnected, well‐managed habitats that complement each other in the resources they offer. To achieve this the Common Agricultural Policy post‐2020 should take a holistic view to implementation that integrates the different delivery vehicles aimed at protecting biodiversity (e.g. enhanced conditionality, eco‐schemes and agri‐environment and climate measures). To improve habitat quality we recommend an effective monitoring framework with target‐orientated indicators and to facilitate the spatial targeting of options collaboration between land managers should be incentivised

Mite species inhabiting commercial bumblebee (Bombus terrestris) nests in Polish greenhouses

Nests of social insects are usually inhabited by various mite species that feed on pollen, other micro-arthropods or are parasitic. Well-known negative effects of worldwide economic importance are caused by mites parasitizing honeybee colonies. Lately, attention has focused on the endoparasitic mite Locustacarus buchneri that has been found in commercial bumblebees. However, little is known of other mites associated with commercial bumblebee nests. Transportation of commercial bumblebee colonies with unwanted residents may introduce foreign mite species to new localities. In this study, we assessed the prevalence and species composition of mites associated with commercial bumblebee nests and determined if the mites are foreign species for Poland and for Europe. The study was conducted on 37 commercial bumblebee nests from two companies (Dutch and Israeli), originating from two greenhouses in southern Poland, and on 20 commercial bumblebee colonies obtained directly from suppliers. The species composition and abundance of mites inhabiting commercial bumblebee nests were determined. Seven mite species from three families were found in nests after greenhouse exploitation. The predominant mite species was Tyrophagus putrescentiae (Acaridae) that was a 100-fold more numerous than representatives of the family Laelapidae (Hypoaspis marginepilosa, H. hyatti, H. bombicolens). Representatives of Parasitidae (Parasitellus fucorum, P. crinitus, P. ignotus) were least numerous. All identified mite species are common throughout Europe, foreign species were not found. Mites were not detected in nests obtained directly from suppliers. We conclude that probably bumblebee nests are invaded by local mite species during greenhouse exploitation