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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.

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.

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.

Lopes, D., E. de Andrade, A. Egartner, F. Beitia, M. Rot, C. Chireceanu, V. Balmés, et al. 2023. FRUITFLYRISKMANAGE: A Euphresco project for Ceratitis capitata Wiedemann (Diptera: Tephritidae) risk management applied in some European countries. EPPO Bulletin. https://doi.org/10.1111/epp.12922

Ceratitis capitata (Wiedemann), the Mediterranean fruit fly or medfly, is one of the world's most serious threats to fresh fruits. It is highly polyphagous (recorded from over 300 hosts) and capable of adapting to a wide range of climates. This pest has spread to the EPPO region and is mainly present in the southern part, damaging Citrus and Prunus. In Northern and Central Europe records refer to interceptions or short‐lived adventive populations only. Sustainable programs for surveillance, spread assessment using models and control strategies for pests such as C. capitata represent a major plant health challenge for all countries in Europe. This article includes a review of pest distribution and monitoring techniques in 11 countries of the EPPO region. This work compiles information that was crucial for a better understanding of pest occurrence and contributes to identifying areas susceptible to potential invasion and establishment. The key outputs and results obtained in the Euphresco project included knowledge transfer about early detection tools and methods used in different countries for pest monitoring. A MaxEnt software model resulted in risk maps for C. capitata in different climatic regions. This is an important tool to help decision making and to develop actions against this pest in the different partner countries.

Kolanowska, M. 2023. Loss of fungal symbionts and changes in pollinator availability caused by climate change will affect the distribution and survival chances of myco-heterotrophic orchid species. Scientific Reports 13. https://doi.org/10.1038/s41598-023-33856-y

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.

Grigoropoulou, A., S. A. Hamid, R. Acosta, E. O. Akindele, S. A. Al‐Shami, F. Altermatt, G. Amatulli, et al. 2023. The global EPTO database: Worldwide occurrences of aquatic insects. Global Ecology and Biogeography. https://doi.org/10.1111/geb.13648

Motivation Aquatic insects comprise 64% of freshwater animal diversity and are widely used as bioindicators to assess water quality impairment and freshwater ecosystem health, as well as to test ecological hypotheses. Despite their importance, a comprehensive, global database of aquatic insect occurrences for mapping freshwater biodiversity in macroecological studies and applied freshwater research is missing. We aim to fill this gap and present the Global EPTO Database, which includes worldwide geo-referenced aquatic insect occurrence records for four major taxa groups: Ephemeroptera, Plecoptera, Trichoptera and Odonata (EPTO). Main type of variables contained A total of 8,368,467 occurrence records globally, of which 8,319,689 (99%) are publicly available. The records are attributed to the corresponding drainage basin and sub-catchment based on the Hydrography90m dataset and are accompanied by the elevation value, the freshwater ecoregion and the protection status of their location. Spatial location and grain The database covers the global extent, with 86% of the observation records having coordinates with at least four decimal digits (11.1 m precision at the equator) in the World Geodetic System 1984 (WGS84) coordinate reference system. Time period and grain Sampling years span from 1951 to 2021. Ninety-nine percent of the records have information on the year of the observation, 95% on the year and month, while 94% have a complete date. In the case of seven sub-datasets, exact dates can be retrieved upon communication with the data contributors. Major taxa and level of measurement Ephemeroptera, Plecoptera, Trichoptera and Odonata, standardized at the genus taxonomic level. We provide species names for 7,727,980 (93%) records without further taxonomic verification. Software format The entire tab-separated value (.csv) database can be downloaded and visualized at https://glowabio.org/project/epto_database/. Fifty individual datasets are also available at https://fred.igb-berlin.de, while six datasets have restricted access. For the latter, we share metadata and the contact details of the authors.

Pelletier, D., and J. R. K. Forrest. 2022. Pollen specialisation is associated with later phenology in Osmia bees (Hymenoptera: Megachilidae). Ecological Entomology. https://doi.org/10.1111/een.13211

Species exhibit a range of specialisation in diet and other niche axes, with specialists typically thought to be more efficient in resource use but more vulnerable to extinction than generalists. Among herbivorous insects, dietary specialists seem more likely to lack acceptable host plants during the insect's feeding stage, owing to fluctuations in host‐plant abundance or phenology. Like other herbivores, bee species vary in host breadth from pollen specialisation (oligolecty) to generalisation (polylecty).Several studies have shown greater interannual variation in flowering phenology for earlier‐flowering plants than later‐flowering plants, suggesting that early‐season bees may experience substantial year‐to‐year variation in the floral taxa available to them.It was therefore reasoned that, among bees, early phenology could be a more viable strategy for generalists, which can use resources from multiple floral taxa, than for specialists. Consequently, it was expected that the median dates of collection of adult specimens to be earlier for generalist species than for specialists. To test this, phenology data and pollen diet information on 67 North American species of the bee genus Osmia was obtained.Controlling for latitude and phylogeny, it was found that dietary generalisation is associated with significantly earlier phenology, with generalists active, on average, 11–14 days earlier than specialists.This result is consistent with the generalist strategy being more viable than the specialist strategy for species active in early spring, suggesting that dietary specialisation may constrain the evolution of bee phenology—or vice versa.

Christman, M. E., L. R. Spears, J. B. U. Koch, T.-T. T. Lindsay, J. P. Strange, C. L. Barnes, and R. A. Ramirez. 2022. Captive Rearing Success and Critical Thermal Maxima of Bombus griseocollis (Hymenoptera: Apidae): A Candidate for Commercialization? J. Brunet [ed.],. Journal of Insect Science 22. https://doi.org/10.1093/jisesa/ieac064

Abstract Commercialized bumble bees (Bombus) are primary pollinators of several crops within open field and greenhouse settings. However, the common eastern bumble bee (Bombus impatiens Cresson, 1863) is the only species widely available for purchase in North America. As an eastern species, concerns have been expressed over their transportation outside of their native range. Therefore, there is a need to identify regionally appropriate candidates for commercial crop pollination services, especially in the western U.S.A. In this study, we evaluated the commercialization potential of brown-belted bumble bees (Bombus griseocollis De Geer, 1773), a broadly distributed species throughout the U.S.A., by assessing nest initiation and establishment rates of colonies produced from wild-caught gynes, creating a timeline of colony development, and identifying lab-reared workers’ critical thermal maxima (CTMax) and lethal temperature (ecological death). From 2019 to 2021, 70.6% of the wild-caught B. griseocollis gynes produced brood in a laboratory setting. Of these successfully initiated nests, 74.8% successfully established a nest (produced a worker), providing guidance for future rearing efforts. Additionally, lab-reared workers produced from wild-caught B. griseocollis gynes had an average CTMax of 43.5°C and an average lethal temperature of 46.4°C, suggesting B. griseocollis can withstand temperatures well above those commonly found in open field and greenhouse settings. Overall, B. griseocollis should continue to be evaluated for commercial purposes throughout the U.S.A.