Donald S. Horning

AbstractBees (Hymenoptera: Apoidea) are vital components of global ecosystems, yet knowledge of their distribution is limited in many regions. Washington state is located in an ecologically diverse part of North America and encompasses habitat types and plant communities known for high bee species richness. To establish a baseline for future studies on bee communities in the state, we used published and unpublished datasets to develop a preliminary annotated checklist of bees occurring in Washington state. We document, with high confidence, 565 species of bees in Washington and identify an additional 102 species likely to occur in the state. We anticipate future research survey efforts, such as the newly initiated Washington Bee Atlas, will discover several species that have the potential to occur in Washington and provide new data for 84 species which have not been recorded in more than 50 years.

Several invasive species can occupy the same geographic area. Interaction between species depends on several factors, and the results of such interactions can be highly diverse. Asparagopsis armata is a invasive red seaweed whose exudates contain a cocktail of toxic halogenated compounds. In this study, the impact of high and low levels of A. armata on the bivalve Ruditapes philippinarum was assessed in a laboratory experiment. Both are prominent invasive species in Europe and could share the same habitats. The effects of the algae were measured at different biological levels, framed by an integrated approach: bioturbation as a proxy for organismal activity and behaviour within the sediment, and several subcellular biomarkers related to oxidative stress and damage, energy metabolism, detoxification, and neurotransmission. While bioturbation revealed the effects of exudates on the bivalve, with a decrease in most parameters when exposed to the different amounts of algae, only marginal responses were found for biomarkers, suggesting a possible temporal decoupling between the behavioural response and the intrinsic biochemical environment. These results denote that despite the recognized potential of biomarkers to address a myriad of situations, a proxy for higher levels of biological organization, such as behaviour, for its integration of lower-level effects, is a robust tool to address complex and lesser-known mixtures of stressors.

We analysed the wild bee community sampled from 1921 to 2018 at a nature preserve in southern Michigan, USA, to study long-term community shifts in a protected area. During an intensive survey in 1972 and 1973, Francis C. Evans detected 135 bee species. In the most recent intensive surveys conducted in 2017 and 2018, we recorded 90 species. Only 58 species were recorded in both sampling periods, indicating a significant shift in the bee community. We found that the bee community diversity, species richness and evenness were all lower in recent samples. Additionally, 64% of the more common species exhibited a more than 30% decline in relative abundance. Neural network analysis of species traits revealed that extirpation from the reserve was most likely for oligolectic ground-nesting bees and kleptoparasitic bees, whereas polylectic cavity-nesting bees were more likely to persist. Having longer phenological ranges also increased the chance of persistence in polylectic species. Further analysis suggests a climate response as bees in the contemporary sampling period had a more southerly overall distribution compared to the historic community. Results exhibit the utility of both long-term data and machine learning in disentangling complex indicators of bee population trajectories.

Biodiversity loss amplifies the need for taxonomic understanding at global, regional, and local scales. The United Nations Environmental Programme Sustainable Development Goals are explicit in their demand for greater accountability with respect to ecosystem management, and Sustainable Development Goal 15, Life on Land, specifically calls for a halt to biodiversity loss. Pollinators (bees and butterflies) are two functional groups with public attention for protection, yet little long-term data availability. National Parks, including those in the United States, act as optimal sites to study biodiversity loss, but historic data tends to vary in availability. This study addresses systematic taxonomic and digitalization biases present within historic (museum), modern (citizen science), and non-digitized (private collection) datasets for Yellowstone and Grand Teton National Parks from 1900 to 2021. We find that, although database record availability is representative of butterfly and bumble bee groups known for the area, categories such as data rescue, digitalization/availability, and management/archiving vary across database types. These findings on virtual datasets offer opportunities for conservationists to understand the efficacy of digitized collections in addressing questions of species loss over time, including the strengths and pitfalls of digitized data repositories. Additionally, virtual datasets can be utilized to monitor biodiversity under Sustainable Development Goal 15 targets while also promoting broader access to resources such as museum collections for educational purposes. Natural history collections (NHCs) work to preserve biodiversity but tend to hold taxonomic biases. The rapid digitalization of species occurrence data works to improve biodiversity understanding. Pollinator NHCs can inform conservation targets like SDG 15, but only for a subset of species. Additional funding towards data digitalization will broaden the understanding of lesser-known taxa. Virtual museum resources should become more readily accessible to educate and engage the public in species conservation work; citizen science applications can act as an additional educational tool to promote public conservation interest. International biodiversity sampling efforts should be encouraged to document species decline.

The introduction of bees for agricultural production in distinct parts of the world and poor management have led to invasion processes that affect biodiversity, significantly impacting native species. Different Bombus species with invasive potential have been recorded spreading in different regions worldwide, generating ecological and economic losses. We applied environmental niche and potential distribution analyses to four species of the genus Bombus to evaluate the similarities and differences between their native and invaded ranges. We found that B. impatiens has an extended environmental niche, going from dry environmental conditions in the native range to warmer and wetter conditions in the invaded range. Bombus ruderatus also exhibited an extended environmental niche with drier and warmer conditions in the invaded range than in its native range. Bombus subterraneus expanded its environmental niche from cooler and wetter conditions in the native range to drier and warmer conditions in the invaded range. Finally, B. terrestris showed the most significant variation in the environmental niche, extending to areas with similar and different environmental conditions from its native range. The distribution models agreed with the known distributions for the four Bombus species, presenting geographic areas known to be occupied by each species in different regions worldwide. The niche analysis indicate shifts in the niches from the native to the invaded distribution area of the bee species. Still, niche similarities were observed in the areas of greatest suitability in the potential distribution for B. ruderatus, B. subterraneus, and B. terrestris, and to a lesser degree in the same areas with B. impatiens. These species require similar environmental conditions as in their native ranges to be established in their introduced ranges. Still, they can adapt to changes in temperature and humidity, allowing them to expand their ranges into new climatic conditions.

Background The recent discovery of emerging relapsing fever group Borrelia (RFGB) species, such as Borrelia miyamotoi, poses a growing threat to public health. However, the global distribution and associated risk burden of these species remain uncertain. We aimed to map the diversity, distribution, and potential infection risk of RFGB.MethodsWe searched PubMed, Web of Science, GenBank, CNKI, and eLibrary from Jan 1, 1874, to Dec 31, 2022, for published articles without language restriction to extract distribution data for RFGB detection in vectors, animals, and humans, and clinical information about human patients. Only articles documenting RFGB infection events were included in this study, and data for RFGB detection in vectors, animals, or humans were composed into a dataset. We used three machine learning algorithms (boosted regression trees, random forest, and least absolute shrinkage and selection operator logistic regression) to assess the environmental, ecoclimatic, biological, and socioeconomic factors associated with the occurrence of four major RFGB species: Borrelia miyamotoi, Borrelia lonestari, Borrelia crocidurae, and Borrelia hermsii; and mapped their worldwide risk level.FindingsWe retrieved 13 959 unique studies, among which 697 met the selection criteria and were used for data extraction. 29 RFGB species have been recorded worldwide, of which 27 have been identified from 63 tick species, 12 from 61 wild animals, and ten from domestic animals. 16 RFGB species caused human infection, with a cumulative count of 26 583 cases reported from Jan 1, 1874, to Dec 31, 2022. Borrelia recurrentis (17 084 cases) and Borrelia persica (2045 cases) accounted for the highest proportion of human infection. B miyamotoi showed the widest distribution among all RFGB, with a predicted environmentally suitable area of 6·92 million km2, followed by B lonestari (1·69 million km2), B crocidurae (1·67 million km2), and B hermsii (1·48 million km2). The habitat suitability index of vector ticks and climatic factors, such as the annual mean temperature, have the most significant effect among all predictive models for the geographical distribution of the four major RFGB species.InterpretationThe predicted high-risk regions are considerably larger than in previous reports. Identification, surveillance, and diagnosis of RFGB infections should be prioritised in high-risk areas, especially within low-income regions.FundingNational Key Research and Development Program of China.

The objective of this research was to assess the genetic diversity and phylogeography of Bombus terrestris and examine the historical events that shaped its contemporary genetic structures using the COI mitochondrial marker. Specimens of the species were collected from its distribution range alongside the Alborz Mountain range, and GenBank sequences from the Eurasian distribution range were incorporated into the dataset. The COI sequences were employed in Bayesian and Maximum Likelihood analyses to generate phylogenetic trees for the species populations and to investigate the evolutionary history of the species. Additionally, species occurrence points and climate data were utilized in Species Distribution Modeling (SDM) analyses to reconstruct the species range under past, present, and future climate conditions. The ML and BI trees yielded similar topologies, indicating extremely low genetic diversity and a homogeneous structure in the species population distribution range in Eurasia. Demographic analyses suggested that the species may have experienced a bottleneck during the last glacial maximum in Eurasia, followed by a recent expansion. The SDM analyses revealed significant fluctuations in the species range in the past and expansion under present conditions. Given the high dispersal ability of the species, the population expansion rate has surpassed the rate of developing new genetic diversity, and the estimated polymorphic sites for the species are likely relatively recent. This low level of genetic variation can also be attributed to the absence of geographical barriers and the excellent flying ability of the queen bee, leading to sustained gene flow throughout the entire continent. Despite the general correlation between larger populations and higher genetic diversity, bumblebees can expand their population size without increasing genetic diversity when residing in resourceful habitats.

Globally, insects have been impacted by climate change, with bumble bees in particular showing range shifts and declining species diversity with global warming. This suggests heat tolerance is a likely factor limiting the distribution and success of these bees. Studies have shown high intraspecific variance in bumble bee thermal tolerance, suggesting biological and environmental factors may be impacting heat resilience. Understanding these factors is important for assessing vulnerability and finding environmental solutions to mitigate effects of climate change. In this study, we assess whether geographic range variation in bumble bees in the eastern United States is associated with heat tolerance and further dissect which other biological and environmental factors explain variation in heat sensitivity in these bees. We examine heat tolerance by caste, sex, and rearing condition (wild/lab) across six eastern US bumble bee species, and assess the role of age, reproductive status, body size, and interactive effects of humidity and temperature on thermal tolerance in Bombus impatiens. We found marked differences in heat tolerance by species that correlate with each species' latitudinal range, habitat, and climatic niche, and we found significant variation in thermal sensitivity by caste and sex. Queens had considerably lower heat tolerance than workers and males, with greater tolerance when queens would first be leaving their natal nest, and lower tolerance after ovary activation. Wild bees tended to have higher heat tolerance than lab reared bees, and body size was associated with heat tolerance only in wild‐caught foragers. Humidity showed a strong interaction with heat effects, pointing to the need to regulate relative humidity in thermal assays and consider its role in nature. Altogether, we found most tested biological conditions impact thermal tolerance and highlight the stages of these bees that will be most sensitive to future climate change.

Climate is a main driver of species distributions, but all species are not equally affected by climate change, and their differential responses to similar climatic constraints might dramatically affect the local species composition. In the context of climate warming, a better knowledge of the ability of dispersal-limited and habitat-specialist species to track climate change at local scale is urgently needed. Comparing the population genetic and demographic impacts of past climate cycles in multiple co-distributed species with similar ecological requirements help predicting the community-scale response to climate warming, but such comparative studies remain rare. Here, we studied the relationship between demographic history and past changes in spatial distribution of three protected peatland butterfly species (Boloria aquilonaris, Coenonympha tullia, Lycaena helle) in the Jura massif (France), using a genomic approach (ddRAD sequencing) and species distribution modeling (SDM). We found a similar and narrow thermal niche among species, and shared demographic histories of post-glacial decline and recent fragmentation of populations. Each species functions as a single metapopulation at the regional scale, with a North-South gradient of decreasing genetic diversity that fits the local dynamics of the ice cover over time. However, we found no correlation between changes in the quantity or the quality of suitable areas and changes in effective population size over time. This suggests that species ranges moved beyond the Jura massif during the less favorable climatic periods, and/or that habitat loss and deterioration are major drivers of the current dramatic decline observed in the three species. Our findings allow better understanding how history events and contemporary dynamics shape local biodiversity, providing valuable knowledge to identify appropriate conservation strategies.

The first comprehensive species distribution models for orchid, its fungal symbionts and pollinator are presented. To evaluate impact of global warming on these organisms three different projections and four various climate change scenarios were analysed. The niche modelling was based on presence-only records of Limodorum abortivum , two species of Russula and three insects pollinating orchid ( Anthophora affinis, Bombus terrestris, Rhodanthidium septemdentatum ). Two sets of orchid predictions were examined—the first one included only climatic data and the second one was based on climate data and data on future distribution of orchid fungal symbionts. Overall, a poleward range shift is predicted to occur as a result of climate change and apparently global warming will be favorable for L. abortivum and its potential geographical range will expand. However, due to the negative effect of global warming on fungal symbionts of L. abortivum , the actual extension of the suitable niches of the orchid will be much limited. Considering future possibility of cross-pollination, the availability of A. affinis for L. abortivum will decrease and this bee will be available in the worst case scenarios only for 21% of orchid populations. On the other hand, the overlap of orchid and the buff-tailed bumblebee will increase and as much as 86.5% of plant populations will be located within B. terrestris potential range. Also the availability of R. septemdentatum will be higher than currently observed in almost all analysed climate change projections. This study showed the importance of inclusion of ecological factors in species distribution models as the climate data itself are not enough to estimate the future distribution of plant species. Moreover, the availability of pollen vectors which is crucial for long-term survival of orchid populations should be analysed in context of climate changes.