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Occurrences of introduced and invasive pollinators are increasing worldwide. To predict the potential impacts of exotic bees on native ecosystems we need to understand their ecological interactions. Life history traits are fundamental for understanding ecological interactions and often help to explain the spread of exotic species. We conducted home-and-away comparisons of life history traits of the first invasive bee in Europe, the sculptured resin bee Megachile sculpturalis Smith 1853. We compiled information on nest architecture, offspring, natural enemies, body size and phenology using published literature, museum specimen, data from citizen science initiatives, field observations and reared specimen. Megachile sculpturalis uses a broad variety of nesting materials for brood cell construction, including even plastic at the exotic range. Body size at warm temperate climate was similar in the native and exotic ranges, but phenology shifted forward by about one month (28.9 ± 3.3 SE days) in the exotic ranges. The abundance of natural enemies was similar between native and exotic ranges but specialist enemies were missing in the exotic ranges. These trait shifts may be explained by founder effects or ecological filtering. The comparison of life history traits in native and exotic ranges sheds light on the ecological-evolutionary process of this quickly spreading species and provides a better understanding of invasion processes in solitary bees.

Abstract Background Facing a surge of COVID-19 cases in late August 2021, the U.S. state of Illinois re-enacted its COVID-19 mask mandate for the general public and issued a requirement for workers in certain professions to be vaccinated against COVID-19 or undergo weekly testing. The mask mandate required any individual, regardless of their vaccination status, to wear a well-fitting mask in an indoor setting. Methods We used Illinois Department of Public Health’s COVID-19 confirmed case and vaccination data and investigated scenarios where masking and vaccination would have been reduced to mimic what would have happened had the mask mandate or vaccine requirement not been put in place. The study examined a range of potential reductions in masking and vaccination mimicking potential scenarios had the mask mandate or vaccine requirement not been enacted. We estimated COVID-19 cases and hospitalizations averted by changes in masking and vaccination during the period covering October 20 to December 20, 2021. Results We find that the announcement and implementation of a mask mandate are likely to correlate with a strong protective effect at reducing COVID-19 burden and the announcement of a vaccinate-or-test requirement among frontline professionals is likely to correlate with a more modest protective effect at reducing COVID-19 burden. In our most conservative scenario, we estimated that from the period of October 20 to December 20, 2021, the mask mandate likely prevented approximately 58,000 cases and 1,175 hospitalizations, while the vaccinate-or-test requirement may have prevented at most approximately 24,000 cases and 475 hospitalizations. Conclusion Our results indicate that mask mandates and vaccine-or-test requirements are vital in mitigating the burden of COVID-19 during surges of the virus.

For online retailers, increasing click-through rates and reducing dropout rates are critical to success. In this study, we examine the effect of verbatim repetition of the website's headline message on the proceed button, based on research on processing fluency. In our field study involving 956 online platform visitors, we found that verbatim repetitions of the header message on the proceed button resulted in an increase in the conversion rate by more than 10 percentage points compared to gist repetitions and new messages. Our findings highlight the importance of simple verbatim features and demonstrate the successful application of processing fluency research to impact consumer behavior.

Bees are the most important group of insect pollinators, but their populations are declining. To gain a better understanding of wild bee responses to different stressors (e.g. land-use change) and conservation measures, regional and national monitoring schemes are currently being established in Germany, which is used here as a model region, and in many other countries. We offer perspectives on how to best design future bee monitoring programs with a focus on evaluating the implementation of conservation measures. We discuss different traditional and novel sampling methods, their efficacy depending on research questions and the life-history traits of target species, and how greater standardization of wild bee sampling and monitoring methods can make data more comparable, contributing to the identification of general trends and mechanisms driving bee populations. Furthermore, the potential impact of bee sampling itself on bee populations is discussed.

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.

Host plants required by specialist bee species may be limited in urban areas. We investigated the effects of urbanisation on Heriades truncorum, a solitary bee species that is a specialist on the plant family Asteraceae. We examined brood cell number, host and native plant pollen proportions (via DNA metabarcoding) and the nutritional composition of pollen provisions in H. truncorum nests. Increasing urbanisation resulted in fewer brood cells and higher plant genus diversity in pollen provisions. Bees collected pollen from non‐native and non‐Asteraceae plant genera, including new records for H. truncorum. Increasing overall plant genus diversity in brood provisions was associated with decreased brood cell numbers. However, an increased diversity of Asteraceae plant genera was associated with increased brood cell number. The proportion of native plant genera and native plant pollen were not associated with changes in brood cell number. Pollen provision nutritional composition was not related to urbanisation or brood cell numbers. Pollen provisions averaged a P:L ratio of ~1:1, similar to Asteraceae. These results suggest that native and non‐native Asteraceae are equally beneficial to H. truncorum in Germany. Moreover, fewer brood cells at more urban sites and an increased diversity of plant pollen suggests that the overall level of resources, particularly Asteraceae plants, could be limited in highly urban landscapes. While H. truncorum is not of high conservation concern, our data demonstrate the mechanisms by which a specialist bee with a more narrow or less common host plant specificity could experience nutritional stress in urban areas and provides mitigation strategies. [ABSTRACT FROM AUTHOR]

Addressing global biodiversity loss requires an expanded focus on multiple dimensions of biodiversity. While most studies have focused on the consequences of plant interspecific diversity, our mechanistic understanding of how genetic diversity within plant species affects plant productivity remains limited. Here, we use a tree species × genetic diversity experiment to disentangle the effects of species diversity and genetic diversity on tree productivity, and how they are related to tree functional diversity and trophic feedbacks. We found that tree species diversity increased tree productivity via increased tree functional diversity, reduced soil fungal diversity, and marginally reduced herbivory. The effects of tree genetic diversity on productivity via functional diversity and soil fungal diversity were negative in monocultures but positive in the mixture of the four tree species tested. Given the complexity of interactions between species and genetic diversity, tree functional diversity and trophic feedbacks on productivity, we suggest that both tree species and genetic diversity should be considered in afforestation.

For online retailers, increasing click-through rates and reducing dropout rates are critical to success. In this study, we examine the effect of verbatim repetition of the website's headline message on the proceed button, based on research on processing fluency. In our field study involving 956 online platform visitors, we found that verbatim repetitions of the header message on the proceed button resulted in an increase in the conversion rate by more than 10 percentage points compared to gist repetitions and new messages. Our findings highlight the importance of simple verbatim features and demonstrate the successful application of processing fluency research to impact consumer behavior. [ABSTRACT FROM AUTHOR]

Abstract Hairiness is a salient trait of insect pollinators that has been linked to thermoregulation, pollen uptake and transportation, and pollination success. Despite its potential importance in pollination ecology, hairiness is rarely included in pollinator trait analyses. This is likely due to the lack of standardized and efficient methods to measure hairiness. We describe a novel methodology that uses a stereomicroscope equipped with a live measurement module software to quantitatively measure two components of hairiness: hair density and hair length. We took measures of the two hairiness components in 109 insect pollinator species (including 52 bee species). We analyzed the relationship between hair density and length and between these two components and body size. We combined hair density and length measures to calculate a hairiness index and tested whether hairiness differed between major pollinator groups and bee genera. Body size was strongly and positively correlated to hair length and weakly and negatively correlated to hair density. The correlation between the two hairiness components was weak and negative. According to our hairiness index, butterflies and moths were the hairiest pollinator group, followed by bees, hoverflies, beetles, and other flies. Among bees, bumblebees (Bombus) and mason bees (Osmia) were the hairiest taxa, followed by digger bees (Anthophorinae), sand bees (Andrena), and sweat bees (Halictini). Our methodology provides an effective and standardized measure of the two components of hairiness (hair density and length), thus allowing for a meaningful interpretation of hairiness. We provide a detailed protocol of our methodology, which we hope will contribute to improve our understanding of pollination effectiveness, thermal biology, and responses to climate change in insects.

In non-pharmaceutical management of COVID-19, occupancy of intensive care units (ICU) is often used as an indicator to inform when to intensify mitigation and thus reduce SARS-CoV-2 transmission, strain on ICUs, and deaths. However, ICU occupancy thresholds at which action should be taken are often selected arbitrarily. We propose a quantitative approach using mathematical modeling to identify ICU occupancy thresholds at which mitigation should be triggered to avoid exceeding the ICU capacity available for COVID-19 patients and demonstrate this approach for the United States city of Chicago. We used a stochastic compartmental model to simulate SARS-CoV-2 transmission and disease progression, including critical cases that would require intensive care. We calibrated the model using daily COVID-19 ICU and hospital census data between March and August 2020. We projected various possible ICU occupancy trajectories from September 2020 to May 2021 with two possible levels of transmission increase and uncertainty in core model parameters. The effect of combined mitigation measures was modeled as a decrease in the transmission rate that took effect when projected ICU occupancy reached a specified threshold. We found that mitigation did not immediately eliminate the risk of exceeding ICU capacity. Delaying action by 7 days increased the probability of exceeding ICU capacity by 10-60% and this increase could not be counteracted by stronger mitigation. Even under modest transmission increase, a threshold occupancy no higher than 60% was required when mitigation reduced the reproductive number Rt to just below 1. At higher transmission increase, a threshold of at most 40% was required with mitigation that reduced Rt below 0.75 within the first two weeks after mitigation. Our analysis demonstrates a quantitative approach for the selection of ICU occupancy thresholds that considers parameter uncertainty and compares relevant mitigation and transmission scenarios. An appropriate threshold will depend on the location, number of ICU beds available for COVID-19, available mitigation options, feasible mitigation strengths, and tolerated durations of intensified mitigation.

Here, Schuldt et al. collate data from two long-term grassland and forest biodiversity experiments to ask how plant diversity facets affect the diversity of higher trophic levels. The results show that positive effects of plant diversity on consumer diversity are mediated by plant structural and functional diversity, and vary across ecosystems and trophic levels.

Urbanization is affecting arthropod communities worldwide, for example by changing the availability of food resources. However, the strength and direction of a community's response is species‐specific and depends on species' trophic level. Here, we investigated interacting species at different trophic levels in nests of cavity‐nesting bees and wasps along two urbanization gradients in four German cities using trap nests. We analysed bee and wasp diversity and their trophic interaction partners by metabarcoding the DNA of bee pollen and preyed arthropods found in wasp nests. We found that the pollen richness increased with increasing distance from city centres and at sites characterized by a high percentage of impervious and developed surface, while the richness of pollinators was unaffected by urbanization. In contrast, species richness of wasps, but not their arthropod prey, was highest at sites with low levels of urbanization. However, the community structure of wasp prey changed with urbanization at both local and regional scales. Throughout the study area, the community of wasps consisted of specialists, while bee species were generalists. Our results suggest that Hymenoptera and their food resources are negatively affected by increasing urbanization. However, to understand distribution patterns of both, wasps and bees in urban settings other factors besides food availability should be considered. [ABSTRACT FROM AUTHOR]