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László, Z., C. Looney, H. Prázsmári, E. Poor, and J. D. Shorthouse. 2024. The cynipid gall wasp Diplolepis rosae is more successful in North America than in Europe because of enemy release. Insect Conservation and Diversity. https://doi.org/10.1111/icad.12745

The Enemy Release Hypothesis predicts that introduced species in their new range are freed from natural enemies (e.g., pathogens, parasitoids and predators) that control their populations.Diplolepis rosae (Hymenoptera, Diplolepididae), native to the Western Palearctic, induces readily apparent galls on wild roses (Rosa spp.) that support a robust component community of inquilines, parasitoids and hyperparasitoids in its native range. D. rosae was introduced to North America in the mid‐1800s, and has since become widespread and common across the continent.We compared the insect communities associated with D. rosae galls from Canada and the US Pacific Northwest with those of Eastern Europe.Throughout its introduced range, parasitism rates were lower compared with galls in their natural range. Component communities were also less diverse and species‐rich. The relationship between gall size and parasitism rates showed no significant difference between the two continents.These results show that the component community in its introduced range is depauperate and provide support for the Enemy Release Hypothesis.

López‐Aguilar, T. P., J. Montalva, B. Vilela, M. P. Arbetman, M. A. Aizen, C. L. Morales, and D. de P. Silva. 2024. Niche analyses and the potential distribution of four invasive bumblebees worldwide. Ecology and Evolution 14. https://doi.org/10.1002/ece3.11200

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.

Li, D., X. Wang, K. Jiang, R. An, Y. Li, and D. Liu. 2024. The impact of climate change and the conservation of the keystone Asian honeybee using niche models and systematic prioritization C. Bahlai [ed.],. Journal of Economic Entomology. https://doi.org/10.1093/jee/toae018

Global warming has seriously disturbed the Earth’s ecosystems, and in this context, Asian honeybee (Apis cerana) has experienced a dramatic decline in recent decades. Here, we examined both direct and indirect effects of climate change on A. cerana through ecological niche modeling of A. cerana, and its disease pathogens (i.e., Chinese sacbrood virus and Melissococcus plutonius) and enemies (i.e., Galleria mellonella and Vespa mandarinia). Ecological niche modeling predicts that climate change will increase the potential suitability of A. cerana, but it will also cause some of the original habitat areas to become unsuitable. Outbreak risks of Chinese sacbrood disease and European Foulbrood will increase dramatically, while those of G. mellonella and V. mandarinia will decrease only slightly. Thus, climate change will produce an unfavorable situation for even maintaining some A. cerana populations in China in the future. Genetic structure analyses showed that the A. cerana population from Hainan Island had significant genetic differentiation from that of the mainland, and there was almost no gene flow between the 2, suggesting that urgent measures are needed to protect the unique genetic resources there. Through taking an integrated planning technique with the Marxan approach, we optimized conservation planning, and identified potential nature reserves (mainly in western Sichuan and southern Tibet) for conservation of A. cerana populations. Our results can provide insights into the potential impact of climate change on A. cerana, and will help to promote the conservation of the keystone honeybee in China and the long-term sustainability of its ecosystem services.

Belotti López de Medina, C. R. 2024. Diet breadth and biodiversity in the pre-hispanic South-Central Andes (Western South America) during the Holocene: An exploratory analysis and review. The Holocene. https://doi.org/10.1177/09596836241231446

This paper presents an exploratory study on the taxonomic diversity of pre-Hispanic archaeofaunas in the South-Central Andes (SCA; western South America) from the Pleistocene-Holocene boundary to the Late-Holocene. The SCA is a complex of diverse environments and has undergone distinct climate events for the last 13,000 years, such as the occurrence of warmer and drier conditions in the Middle-Holocene. The South-Central Andean area was part of the larger Andes interaction area, which was a primary center for animal and plant domestication and the emergence of agro-pastoralist economies. Since subsistence was key to these processes, the SCA provides a relevant case study on the interactions among environment, foodways and sociocultural evolution. Taxonomic diversity was used here as a proxy for diet breadth. A total of 268 archaeofaunal assemblages were sampled from the zooarchaeological literature. Reviewed variables included the cultural chronology and spatial coordinates of the assemblages, as well as the presence and abundance of taxa at the family rank. Taxonomic diversity covered two dimensions: composition (families present in each assemblage) and structure (quantitative relationships among taxa), which was measured through richness (NTAXA), ubiquity and relative abundance (NISP based rank-order). Despite the uneven distribution of samples, the analyses revealed the following trends: (1) a moderate relationship between NTAXA and distance from coastline for most of the Holocene; (2) a potential decrease in assemblage richness for coastal ecoregions during the Late-Holocene; and (3) a generalized increase in the relative abundance of Camelidae.

Boxler, B. M., C. S. Loftin, and W. B. Sutton. 2024. Monarch Butterfly (Danaus plexippus) Roost Site-Selection Criteria and Locations East of the Appalachian Mountains, U.S.A. Journal of Insect Behavior. https://doi.org/10.1007/s10905-023-09844-5

The monarch butterfly is a flagship species and pollinator whose populations have declined by 85% in the recent two decades. Their largest population overwinters in Mexico, then disperses across eastern North America during March to August. During September-December, they return south using two flyways, one that spans the central United States and another that follows the Atlantic coast. Migrating monarchs fly diurnally and roost in groups nocturnally. We sought to determine the criteria this species uses to select roost sites, and the landscape context where those sites are found. We developed species distribution models of the landscape context of Atlantic flyway roost sites via citizen scientist observations and environmental variables that affect monarchs in the adult stage prior to migration, using two algorithms (Maximum Entropy and Genetic Algorithm for Ruleset Prediction). We developed two model validation methods: a citizen scientist smartphone application and peer-informed comparisons with aerial imagery. Proximity to surface water, elevation, and vegetative cover were the most important criteria for monarch roost site selection. Our model predicted 2.6 million ha (2.9% of the study area) of suitable roosting habitat in the Atlantic flyway, with the greatest availability along the Atlantic coastal plain and Appalachian Mountain ridges. Conservation of this species is difficult, as monarchs range over both large areas and various habitat types, and most current monarch research and conservation efforts are focused on the breeding and overwintering periods. These models can serve to help prioritize surveys of roosting sites and conservation efforts during the monarchs’ fall migration.

Melin, A., C. M. Beale, J. C. Manning, and J. F. Colville. 2024. Fine‐scale bee species distribution models: Hotspots of richness and endemism in South Africa with species‐area comparisons. Insect Conservation and Diversity. https://doi.org/10.1111/icad.12715

While global patterns of bee diversity have been modelled, our understanding of fine‐scale regional patterns is more limited, particularly for under‐sampled regions such as Africa. South Africa is among the exceptions on the African continent; its bee fauna (ca. 1253 species) has been well collected and documented, including mass digitising of its natural history collections. It is a region with high floral diversity, high habitat heterogeneity and variable rainfall seasonality.Here, we combine a South African bee species distributional database (877 bee species) with a geospatial modelling approach to determine fine‐scale (~11 × 11 km grid cell resolution) hotspots of bee species richness, endemism and range‐restricted species.Our analyses, based on the probabilities of occurrence surfaces for each species across 108,803 two‐minute grid cells, reveal three bee hotspots of richness: Winter rainfall, Aseasonal rainfall and Early‐to‐late summer rainfall. These hotspots contain large numbers of endemic and geographically restricted taxa. Hotspots with particularly high bee diversity include the Fynbos, Succulent Karoo and Desert biomes; the latter showing 6–20 times more species per unit area than other biomes. Our results conform with global species‐area patterns: areas of higher‐than‐expected bee density are largely concentrated in Mediterranean and arid habitats.This study further enhances our knowledge in identifying regional and global hotspots of richness and endemism for a keystone group of insects and enabling these to be accounted for when setting conservation priorities.

Ranjbaran, Y., D. Rödder, R. Saberi-Pirooz, and F. Ahmadzadeh. 2024. What happens in ice age, does not stay in ice age: Phylogeography of Bombus terrestris revealed a low genetic diversity amongst the Eurasian populations. Global Ecology and Conservation 49: e02775. https://doi.org/10.1016/j.gecco.2023.e02775

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.

Feuerborn, C., G. Quinlan, R. Shippee, T. L. Strausser, T. Terranova, C. M. Grozinger, and H. M. Hines. 2023. Variance in heat tolerance in bumble bees correlates with species geographic range and is associated with several environmental and biological factors. Ecology and Evolution 13. https://doi.org/10.1002/ece3.10730

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.

de Pedro, D., F. S. Ceccarelli, R. Vandame, J. Mérida, and P. Sagot. 2023. Congruence between species richness and phylogenetic diversity in North America for the bee genus Diadasia (Hymenoptera: Apidae). Biodiversity and Conservation. https://doi.org/10.1007/s10531-023-02706-8

The current ecological crisis stemming from the loss of biodiversity and associated ecosystem services, highlights the urgency of documenting diversity and distribution. Bees are a classical example of an ecologically and economically important group, due to their high diversity and varied ecosystem services, especially pollination. Here, two common biodiversity indices, namely species richness and phylogenetic diversity, are evaluated geographically to determine the best approach for selecting areas of conservation priority. The model organisms used in this study are the North American species belonging to the bee genus Diadasia (Apidae). Based on the results obtained by analyzing distributional records and a molecular phylogeny, we can see that species richness and phylogenetic diversity are closely linked, although phylogenetic diversity provides a more detailed assessment of the spatial distribution of diversity. Therefore, while either one of these commonly used indices are valid as far as selecting areas of conservation priority, we recommend, if possible, to include genetic information in biodiversity and conservation studies.

Calvente, A., A. P. Alves da Silva, D. Edler, F. A. Carvalho, M. R. Fantinati, A. Zizka, and A. Antonelli. 2023. Spiny but photogenic: amateur sightings complement herbarium specimens to reveal the bioregions of cacti. American Journal of Botany. https://doi.org/10.1002/ajb2.16235

Premise: Cacti are characteristic elements of the Neotropical flora and of major interest for biogeographic, evolutionary, and ecological studies. Here we test global biogeographic boundaries for Neotropical Cactaceae using specimen‐based occurrences coupled with data from visual observations, as a means to tackle the known collection biases in the family.MethodsSpecies richness and record density were assessed for preserved specimens and human observations and a bioregional scheme tailored to Cactaceae was produced using the interactive web application Infomap Bioregions based on data from 261,272 point records cleaned through automated and manual steps.Key ResultsWe find that areas in Mexico and southwestern USA, Eastern Brazil and along the Andean region have the greatest density of records and the highest species richness. Human observations complement information from preserved specimens substantially, especially along the Andes. We propose 24 cacti bioregions, among which the most species‐rich are: northern Mexico/southwestern USA, central Mexico, southern central Mexico, Central America, Mexican Pacific coast, central and southern Andes, northwestern Mexico/extreme southwestern USA, southwestern Bolivia, northeastern Brazil, Mexico/Baja California.ConclusionsThe bioregionalization proposed shows biogeographical boundaries specific to cacti, and can thereby aid further evolutionary, biogeographic, and ecological studies by providing a validated framework for further analyses. This classification builds upon, and is distinctive from, other expert‐derived regionalization schemes for other taxa. Our results showcase how observation data, including citizen‐science records, can complement traditional specimen‐based data for biogeographic research, particularly for taxa with specific specimen collection and preservation challenges and those that are threatened or internationally protected.This article is protected by copyright. All rights reserved.