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Pathogens and parasites of solitary bees have been studied for decades, but the microbiome as a whole is poorly understood for most taxa. Comparative analyses of microbiome features such as composition, abundance, and specificity, can shed light on bee ecology and the evolution of host–microbe interactions. Here we study microbiomes of ground-nesting cellophane bees (Colletidae: Diphaglossinae). From a microbial point of view, the diphaglossine genus Ptiloglossa is particularly remarkable: their larval provisions are liquid and smell consistently of fermentation. We sampled larval provisions and various life stages from wild nests of Ptiloglossa arizonensis and two species of closely related genera: Caupolicana yarrowi and Crawfordapis luctuosa . We also sampled nectar collected by P. arizonensis . Using 16S rRNA gene sequencing, we find that larval provisions of all three bee species are near-monocultures of lactobacilli. Nectar communities are more diverse, suggesting ecological filtering. Shotgun metagenomic and phylogenetic data indicate that Ptiloglossa culture multiple species and strains of Apilactobacillus , which circulate among bees and flowers. Larval lactobacilli disappear before pupation, and hence are likely not vertically transmitted, but rather reacquired from flowers as adults. Thus, brood cell microbiomes are qualitatively similar between diphaglossine bees and other solitary bees: lactobacilli-dominated, environmentally acquired, and non-species-specific. However, shotgun metagenomes provide evidence of a shift in bacterial abundance. As compared with several other bee species, Ptiloglossa have much higher ratios of bacterial to plant biomass in larval provisions, matching the unusually fermentative smell of their brood cells. Overall, Ptiloglossa illustrate a path by which hosts can evolve quantitatively novel symbioses: not by acquiring or domesticating novel symbionts, but by altering the microenvironment to favor growth of already widespread and generalist microbes. 

Neutron-capture cross sections of neutron-rich nuclei are calculated using a Hauser–Feshbach model when direct experimental cross sections cannot be obtained. A number of codes to perform these calculations exist, and each makes different assumptions about the underlying nuclear physics. We investigated the systematic uncertainty associated with the choice of Hauser-Feshbach code used to calculate the neutron-capture cross section of a short-lived nucleus. The neutron-capture cross section for$$^{73}\hbox {Zn}$$${}^{73}\text{Zn}$(n,$$\gamma $$$\gamma$)$$^{74}\hbox {Zn}$$${}^{74}\text{Zn}$was calculated using three Hauser-Feshbach statistical model codes: TALYS, CoH, and EMPIRE. The calculation was first performed without any changes to the default settings in each code. Then an experimentally obtained nuclear level density (NLD) and$$\gamma $$$\gamma$-ray strength function ($$\gamma \hbox {SF}$$$\gamma \text{SF}$) were included. Finally, the nuclear structure information was made consistent across the codes. The neutron-capture cross sections obtained from the three codes are in good agreement after including the experimentally obtained NLD and$$\gamma \hbox {SF}$$$\gamma \text{SF}$, accounting for differences in the underlying nuclear reaction models, and enforcing consistent approximations for unknown nuclear data. It is possible to use consistent inputs and nuclear physics to reduce the differences in the calculated neutron-capture cross section from different Hauser-Feshbach codes. However, ensuring the treatment of the input of experimental data and other nuclear physics are similar across multiple codes requires a careful investigation. For this reason, more complete documentation of the inputs and physics chosen is important.

 

Despite the increasingly documented occurrence of individual specialization, the relationship between individual consumer interactions and diet-related microbial communities in wild populations is still unclear. Using data from nests of the bee Ceratina australensis from three different wild populations, we combine metabarcoding and network approaches to explore the existence of individual variation in resource use within and across populations, and whether dietary specialization affects the richness of pollen-associated microbes. We reveal the existence of marked dietary specialization. In the most specialized population, we also show that individuals' diet breadth was positively related to the richness of fungi, but not bacteria. Overall, individual specialization appeared to have a weak or negligible effect on the microbial richness of nests, suggesting that different mechanisms beyond environmental transmission may be at play regarding microbial acquisition in wild bees. 

We report the discovery of two mini-Neptunes in near 2:1 resonance orbits (P = 7.610303 d for HIP 113103 b and P  = 14.245651 d for HIP 113103 c) around the adolescent K-star HIP 113103 (TIC 121490076). The planet system was first identified from the TESS mission, and was confirmed via additional photometric and spectroscopic observations, including a ∼17.5 h observation for the transits of both planets using ESA CHEOPS. We place ≤4.5 min and ≤2.5 min limits on the absence of transit timing variations over the 3 yr photometric baseline, allowing further constraints on the orbital eccentricities of the system beyond that available from the photometric transit duration alone. With a planetary radius of Rp  =  $1.829_{-0.067}^{+0.096}$ R⊕, HIP 113103 b resides within the radius gap, and this might provide invaluable information on the formation disparities between super-Earths and mini-Neptunes. Given the larger radius Rp  = $2.40_{-0.08}^{+0.10}$ R⊕ for HIP 113103 c, and close proximity of both planets to HIP 113103, it is likely that HIP 113103 b might have lost (or is still losing) its primordial atmosphere. We therefore present simulated atmospheric transmission spectra of both planets using JWST, HST, and Twinkle. It demonstrates a potential metallicity difference (due to differences in their evolution) would be a challenge to detect if the atmospheres are in chemical equilibrium. As one of the brightest multi sub-Neptune planet systems suitable for atmosphere follow up, HIP 113103 b and HIP 113103 c could provide insight on planetary evolution for the sub-Neptune K-star population.

 

Abstract We examine the impact of writing-to-learn (WTL) on promoting conceptual understanding of introductory materials science and engineering, including crystal structures, stress–strain behavior, phase diagrams, and corrosion. We use an analysis of writing products in comparison with pre/post concept-inventory-style assessments. For all topics, statistically significant improvements between draft and revision scores are apparent. For the stress–strain and phase diagram WTL assignments that require synthesis of qualitative data into quantitative formats, while emphasizing microstructure-properties correlations, the highest WTL effect sizes and medium-to-high gains on corresponding assessments are observed. We present these findings and suggest strategies for future WTL design and implementation. Graphic abstract 

Abstract Floral nectar, an important resource for pollinators, is inhabited by microbes such as yeasts and bacteria, which have been shown to influence pollinator preference. Dynamic and complex plant-pollinator-microbe interactions are likely to be affected by a rapidly changing climate, as each player has their own optimal growth temperatures and phenological responses to environmental triggers, such as temperature. To understand how warming due to climate change is influencing nectar microbial communities, we incubated a natural nectar microbial community at different temperatures and assessed the subsequent nectar chemistry and preference of the common eastern bumble bee, Bombus impatiens . The microbial community in floral nectar is often species-poor, and the cultured Brassica rapa nectar community was dominated by the bacterium Fructobacillus . Temperature increased the abundance of bacteria in the warmer treatment. Bumble bees preferred nectar inoculated with microbes, but only at the lower, ambient temperature. Warming therefore induced an increase in bacterial abundance which altered nectar sugars and led to significant differences in pollinator preference. 

ABSTRACT Diet and gut microbiomes are intricately linked on both short and long timescales. Changes in diet can alter the microbiome, while microbes in turn allow hosts to access novel diets. Bees are wasps that switched to a vegetarian lifestyle, and the vast majority of bees feed on pollen and nectar. Some stingless bee species, however, also collect carrion, and a few have fully reverted to a necrophagous lifestyle, relying on carrion for protein and forgoing flower visitation altogether. These “vulture” bees belong to the corbiculate apid clade, which is known for its ancient association with a small group of core microbiome phylotypes. Here, we investigate the vulture bee microbiome, along with closely related facultatively necrophagous and obligately pollinivorous species, to understand how these diets interact with microbiome structure. Via deep sequencing of the 16S rRNA gene and subsequent community analyses, we find that vulture bees have lost some core microbes, retained others, and entered into novel associations with acidophilic microbes found in the environment and on carrion. The abundance of acidophilic bacteria suggests that an acidic gut is important for vulture bee nutrition and health, as has been found in other carrion-feeding animals. Facultatively necrophagous bees have more variable microbiomes than strictly pollinivorous bees, suggesting that bee diet may interact with microbiomes on both short and long timescales. Further study of vulture bees promises to provide rich insights into the role of the microbiome in extreme diet switches. IMPORTANCE When asked where to find bees, people often picture fields of wildflowers. While true for almost all species, there is a group of specialized bees, also known as the vulture bees, that instead can be found slicing chunks of meat from carcasses in tropical rainforests. In this study, researchers compared the microbiomes of closely related bees that live in the same region but vary in their dietary lifestyles: some exclusively consume pollen and nectar, others exclusively depend on carrion for their protein, and some consume all of the above. Researchers found that vulture bees lost some ancestral “core” microbes, retained others, and entered into novel associations with acidophilic microbes, which have similarly been found in other carrion-feeding animals such as vultures, these bees’ namesake. This research expands our understanding of how diet interacts with microbiomes on both short and long timescales in one of the world’s biodiversity hot spots. 

Bees collect pollen from flowers for their offspring, and by doing so contribute critical pollination services for our crops and ecosystems. Unlike many managed bee species, wild bees are thought to obtain much of their microbiome from the environment. However, we know surprisingly little about what plant species bees visit and the microbes associated with the collected pollen. Here, we addressed the hypothesis that the pollen and microbial components of bee diets would change across the range of the bee, by amplicon sequencing pollen provisions of a widespread small carpenter bee, Ceratina calcarata, across three populations. Ceratina calcarata was found to use a diversity of floral resources across its range, but the bacterial genera associated with pollen provisions were very consistent. Acinetobacter, Erwinia, Lactobacillus, Sodalis, Sphingomonas and Wolbachia were among the top ten bacterial genera across all sites. Ceratina calcarata uses both raspberry (Rubus) and sumac (Rhus) stems as nesting substrates, however nests within these plants showed no preference for host plant pollen. Significant correlations in plant and bacterial co-occurrence differed between sites, indicating that many of the most common bacterial genera have either regional or transitory floral associations. This range-wide study suggests microbes present in brood provisions are conserved within a bee species, rather than mediated by climate or pollen composition. Moving forward, this has important implications for how these core bacteria affect larval health and whether these functions vary across space and diet. These data increase our understanding of how pollinators interact with and adjust to their changing environment.