The Extraordinary Alkali Bee, Nomia melanderi (Halictidae), the World's Only Intensively Managed Ground-Nesting Bee

Among the ground-nesting bees are several proven crop pollinators, but only the alkali bee (Nomia melanderi) has been successfully managed. In <80 years, it has become the world's most intensely studied ground-nesting solitary bee. In many ways, the bee seems paradoxical. It nests during the torrid, parched midsummer amid arid valleys and basins of the western United States, yet it wants damp nesting soil. In these basins, extensive monocultures of an irrigated Eurasian crop plant, alfalfa (lucerne), subsidize millions of alkali bees. Elsewhere, its polylectic habits and long foraging range allow it to stray into neighboring crops contaminated with insecticides. Primary wild floral hosts are either non-native or poorly known. Kleptoparasitic bees plague most ground nesters, but not alkali bees, which do, however, host other well-studied parasitoids. Building effective nesting beds requires understanding the hydraulic conductivity of silty nesting soils and its important interplay with specific soil mineral salts. Surprisingly, some isolated populations endure inhospitably cold climates by nesting amid hot springs. Despite the peculiarities and challenges associated with its management, the alkali bee remains the second most valuable managed solitary bee for US agriculture and perhaps the world.

Trace metals with heavy consequences on bees: A comprehensive review

The pervasiveness of human imprint on Earth is alarming and most animal species, including bees (Hymenoptera: Apoidea: Anthophila), must cope with several stressors. Recently, exposure to trace metals and metalloids (TMM) has drawn attention and has been suggested as a threat for bee populations. In this review, we aimed at bringing together all the studies (n = 59), both in laboratories and in natura, that assessed the effects of TMM on bees. After a brief comment on semantics, we listed the potential routes of exposure to soluble and insoluble (i.e. nanoparticle) TMM, and the threat posed by metallophyte plants. Then, we reviewed the studies that addressed whether bees could detect and avoid TMM in their environment, as well as the ways bee detoxify these xenobiotics. Afterwards, we listed the impacts TMM have on bees at the community, individual, physiological, histological and microbial levels. We discussed around the interspecific variations among bees, as well as around the simultaneous exposure to TMM. Finally, we highlighted that bees are likely exposed to TMM in combination or with other stressors, such as pesticides and parasites. Overall, we showed that most studies focussed on the domesticated western honey bee and mainly addressed lethal effects. Because TMM are widespread in the environment and have been shown to result in detrimental consequences, evaluating their lethal and sublethal effects on bees, including non-Apis species, warrants further investigations.

The genus Epeolus Latreille, 1802 (Hymenoptera, Apidae) in Central Asia

Available information about bees of the genus Epeolus in Central Asia is summarized. Twenty species are currently known from this area. Two new species are described: E.albus Astafurova & Proshchalykin, sp. nov. and E.pesenkoi Astafurova, sp. nov. Two species are newly recorded from Central Asia: E.asiaticus Astafurova & Proshchalykin, 2022 and E.nudiventris Bischoff, 1930. The hitherto unknown male of E.mikhailovi Astafurova & Proshchalykin, 2021 is described, and lectotypes are designated for E.ruficornis Morawitz, 1875 and E.vinogradovi Popov, 1952.

Forests are critically important to global pollinator diversity and enhance pollination in adjacent crops

Although the importance of natural habitats to pollinator diversity is widely recognized, the value of forests to pollinating insects has been largely overlooked in many parts of the world. In this review, we (i) establish the importance of forests to global pollinator diversity, (ii) explore the relationship between forest cover and pollinator diversity in mixed-use landscapes, and (iii) highlight the contributions of forest-associated pollinators to pollination in adjacent crops. The literature shows unambiguously that native forests support a large number of forest-dependent species and are thus critically important to global pollinator diversity. Many pollinator taxa require or benefit greatly from resources that are restricted to forests, such as floral resources provided by forest plants (including wind-pollinated trees), dead wood for nesting, tree resins, and various non-floral sugar sources (e.g. honeydew). Although landscape-scale studies generally support the conclusion that forests enhance pollinator diversity, findings are often complicated by spatial scale, focal taxa, landscape context, temporal context, forest type, disturbance history, and external stressors. While some forest loss can be beneficial to pollinators by enhancing habitat complementarity, too much can result in the near-elimination of forest-associated species. There is strong evidence from studies of multiple crop types that forest cover can substantially increase yields in adjacent habitats, at least within the foraging ranges of the pollinators involved. The literature also suggests that forests may have enhanced importance to pollinators in the future given their role in mitigating the negative effects of pesticides and climate change. Many questions remain about the amount and configuration of forest cover required to promote the diversity of forest-associated pollinators and their services within forests and in neighbouring habitats. However, it is clear from the current body of knowledge that any effort to preserve native woody habitats, including the protection of individual trees, will benefit pollinating insects and help maintain the critical services they provide.

Stingless bee classification and biology (Hymenoptera, Apidae): a review, with an updated key to genera and subgenera

Stingless bees (Meliponini) are a ubiquitous and diverse element of the pantropical melittofauna, and have significant cultural and economic importance. This review outlines their diversity, and provides identification keys based on external morphology, brief accounts for each of the recognized genera, and an updated checklist of all living and fossil species. In total there are currently 605 described extant species in 45 extant genera, and a further 18 extinct species in nine genera, seven of which are extinct. A new fossil genus, Adactylurina Engel, gen. nov., is also described for a species in Miocene amber from Ethiopia. In addition to the systematic review, the biology of stingless bees is summarized with an emphasis on aspects related to their nesting biology and architecture.

Bees just wanna have fungi: a review of bee associations with nonpathogenic fungi

Bee-fungus associations are common, and while most studies focus on entomopathogens, emerging evidence suggests that bees associate with a variety of symbiotic fungi that can influence bee behavior and health. Here, we review nonpathogenic fungal taxa associated with different bee species and bee-related habitats. We synthesize results of studies examining fungal effects on bee behavior, development, survival, and fitness. We find that fungal communities differ across habitats, with some groups restricted mostly to flowers (Metschnikowia), while others are present almost exclusively in stored provisions (Zygosaccharomyces). Starmerella yeasts are found in multiple habitats in association with many bee species. Bee species differ widely in the abundance and identity of fungi hosted. Functional studies suggest that yeasts affect bee foraging, development, and pathogen interactions, though few bee and fungal taxa have been examined in this context. Rarely, fungi are obligately beneficial symbionts of bees, whereas most are facultative bee associates with unknown or ecologically contextual effects. Fungicides can reduce fungal abundance and alter fungal communities associated with bees, potentially disrupting bee-fungi associations. We recommend that future study focus on fungi associated with non-honeybee species and examine multiple bee life stages to document fungal composition, abundance, and mechanistic effects on bees.

Declines of bees and butterflies over 15 years in a forested landscape

Despite growing concerns about pollinator declines,^1,2,3,4 evidence that this is a widespread problem affecting entire communities remains limited.⁵ There is a particular shortage of pollinator time series from relatively undisturbed natural habitats, such as forests, which are generally thought to provide refuge to biodiversity from anthropogenic stressors.⁶ Here, we present the results from standardized pollinator sampling over 15 years (2007-2022) at three relatively undisturbed forested locations in the southeastern United States. We observed significant declines in the richness (39%) and abundance (62.5%) of bees as well as the abundance of butterflies (57.6%) over this time period. Unexpectedly, we detected much stronger declines in the richness and abundance of above-ground-nesting bees (81.1% and 85.3%, respectively) compared with below-ground-nesting bees. Even after dropping the first or last year of sampling, which happened to yield the greatest and lowest numbers of pollinators, respectively, we still detected many of the same negative trends. Our results suggest that sharp declines in pollinators may not be limited to areas experiencing direct anthropogenic disturbances. Possible drivers in our system include increasing mean annual minimum temperatures near our study sites as well as an invasive wood-nesting ant that has become increasingly widespread and abundant in the region over the course of this study.

Spatial mismatch between wild bee diversity hotspots and protected areas

Wild bees are critical for multiple ecosystem functions but are currently threatened. Understanding the determinants of the spatial distribution of wild bee diversity is a major research gap for their conservation. We modeled wild bee α and β taxonomic and functional diversity in Switzerland to uncover countrywide diversity patterns and determine the extent to which they provide complementary information, assess the importance of the different drivers structuring wild bee diversity, identify hotspots of wild bee diversity, and determine the overlap between diversity hotspots and the network of protected areas. We used site-level occurrence and trait data from 547 wild bee species across 3343 plots and calculated community attributes, including taxonomic diversity metrics, community mean trait values, and functional diversity metrics. We modeled their distribution with predictors describing gradients of climate, resource availability (vegetation), and anthropogenic influence (i.e., land-use types and beekeeping intensity). Wild bee diversity changed along gradients of climate and resource availability; high-elevation areas had lower functional and taxonomic α diversity, and xeric areas harbored more diverse bee communities. Functional and taxonomic β diversities diverged from this pattern, with high elevations hosting unique species and trait combinations. The proportion of diversity hotspots included in protected areas depended on the biodiversity facet, but most diversity hotspots occurred in unprotected land. Climate and resource availability gradients drove spatial patterns of wild bee diversity, resulting in lower overall diversity at higher elevations, but simultaneously greater taxonomic and functional uniqueness. This spatial mismatch among distinct biodiversity facets and the degree of overlap with protected areas is a challenge to wild bee conservation, especially in the face of global change, and calls for better integrating unprotected land. The application of spatial predictive models represents a valuable tool to aid the future development of protected areas and achieve wild bee conservation goals.

Changes in Community Composition and Functional Traits of Bumblebees in an Alpine Ecosystem Relate to Climate Warming

Climate warming has been observed as the main cause of changes in diversity, community composition, and spatial distribution of different plant and invertebrate species. Due to even stronger warming compared to the global mean, bumblebees in alpine ecosystems are particularly exposed to these changes. To investigate the effects of climate warming, we sampled bumblebees along an elevational gradient, compared the records with data from 1935 and 1936, and related our results to climate models. We found that bumblebee community composition differed significantly between sampling periods and that increasing temperatures in spring were the most plausible factor explaining these range shifts. In addition, species diversity estimates were significantly lower compared to historical records. The number of socio-parasitic species was significantly higher in the historical communities, while recent communities showed increases in climate generalists and forest species at lower elevations. Nevertheless, no significant changes in community-weighted means of a species temperature index (STI) or the number of cold-adapted species were detected, likely due to the historical data resolution. We conclude that the composition and functionality of bumblebee communities in the study area have been significantly affected by climate warming, with changes in land use and vegetation cover likely playing an additional important role.

The potential and realized foraging movements of bees are differentially determined by body size and sociality

Reversing biodiversity declines requires a better understanding of organismal mobility, as movement processes dictate the scale at which species interact with the environment. Previous studies have demonstrated that species foraging ranges, and therefore, habitat use increases with body size. Yet, foraging ranges are also affected by other life-history traits, such as sociality, which influence the need of and ability to detect resources. We evaluated the effect of body size and sociality on potential and realized foraging ranges using a compiled dataset of 383 measurements for 81 bee species. Potential ranges were larger than realized ranges and increased more steeply with body size. Highly eusocial species had larger realized foraging ranges than primitively eusocial or solitary taxa. We contend that potential ranges describe species movement capabilities, whereas realized ranges depict how foraging movements result from interactions between species traits and environmental conditions. Furthermore, the complex communication strategies and large colony sizes in highly eusocial species may facilitate foraging over wider areas in response to resource depletion. Our findings should contribute to a greater understanding of landscape ecology and conservation, as traits that influence movement mediate species vulnerability to habitat loss and fragmentation.

The bees of the genus Andrena Fabricius, 1775 (Hymenoptera, Andrenidae) described by Ferdinand Morawitz from the collection of Aleksey Fedtschenko

The type specimens of the genus Andrena Fabricius, 1775, described by Ferdinand Morawitz from the collection of Aleksey Fedtschenko deposited in the Zoological Museum of the Moscow State University and in the Zoological Institute, Russian Academy of Sciences, St. Petersburg (Russia), are critically reviewed. Precise information with illustrations of types for 52 taxa is provided; of these 39 species are valid and thirteen are invalid (ten synonyms and three homonyms). Lectotypes are here designated for the following 24 nominal taxa: Andrenaacutilabris Morawitz, 1876, A.aulica Morawitz, 1876, A.bicarinata Morawitz, 1876, A.combusta Morawitz, 1876, A.comparata Morawitz, 1876, A.corallina Morawitz, 1876, A.discophora Morawitz, 1876, A.fedtschenkoi Morawitz, 1876, A.initialis Morawitz, 1876, A.laeviventris Morawitz, 1876, A.leucorhina Morawitz, 1876, A.mucorea Morawitz, 1876, A.nitidicollis Morawitz, 1876, A.oralis Morawitz, 1876, A.planirostris Morawitz, 1876, A.ravicollis Morawitz, 1876, A.rufilabris Morawitz, 1876, A.sarta Morawitz, 1876, A.smaragdina Morawitz, 1876, A.sogdiana Morawitz, 1876, A.subaenescens Morawitz, 1876, A.tuberculiventris Morawitz, 1876, A.turkestanica Morawitz, 1876, and A.virescens Morawitz, 1876.

Updating the list of flower-visiting bees, hoverflies and wasps in the central atolls of Maldives, with notes on land-use effects

Maldives islands host a unique biodiversity, but their integrity is threatened by climate change and impacting land-uses (e.g. cemented or agricultural areas). As pollinators provide key services for the ecosystems and for the inhabitants, it is crucial to know which pollinators occur in the islands, to characterise their genetic identity and to understand which plants they visit and the size of the human impact. Given that no significant faunistic surveys of Hymenoptera have been published for the country in more than 100 years and that Syrphidae were only partly investigated, we sampled islands in the central part of the Maldives country (Faafu and Daahlu atolls) and hand-netted flower-visiting bees, wasps and hoverflies (Hymenoptera: Anthophila, Crabronidae, Sphecidae, Vespidae, Scoliidae and Diptera: Syrphidae). Overall, we found 21 species; 76.4% of the collected specimens were Anthophila (bees), 12.7% belonged to several families of wasps and 10.8% of individuals were Syrphidae. It seems that one third of species are new for the Maldives, based on the published literature. Human land-uses seem to shape the local pollinator fauna since the assemblages of bees, wasps and hoverflies from urbanised and agricultural islands differed from those in resort and natural ones. These pollinators visited 30 plant species in total, although some invasive plants hosted the highest number of flower visitor species. Biogeographically, this pollinating fauna is mostly shared with Sri Lanka and India. Genetically, the used marker hinted for a unique fauna in relation to the rest of the distribution ranges in most cases, although generally within the level of intraspecific genetic variation. This study significantly contributes to increasing the knowledge on the pollinator diversity and genetic identity in Maldives islands also considering the important implications for the islands' land-use and the role of invasive plants. This study will be pivotal for future pollination studies and biodiversity conservation efforts in the region.

First occurrence of the little-known genus Noteriades (Hymenoptera, Megachilidae) from Vietnam: discovery of a new species and a key to the Southeast Asian fauna

The little-known megachiline genus Noteriades Cockerell, 1931 is recorded from Vietnam for the first time. A new species, Noteriadeshangkia Tran, Engel & Nguyen sp. nov. is described and figured based on a series of females collected from the provinces of the northern and central highlands of Vietnam. The genus is briefly discussed and a new subtribe is established, Noteriadina Engel, Tran & Nguyen subtrib. nov. of Megachilini. Lastly, an identification key and distribution map are provided for those species occurring in Southeast Asia.

What Can Restoration Do for Bee Communities? An Example in the Atlantic Rainforest in Paraná State, Southern Brazil

Biodiversity conservation is a challenge for today. Studies regarding different ecosystems have become extremely important for understanding communities and promoting strategies for conservation, especially those involving forest restoration as strategy to reverse biodiversity loss. We compared bee diversity indices between three remnants of Atlantic rainforest in southern Brazil and four adjacent areas that were reforested after shale mining, and which are now under different restoration levels. Seven sites were monitored for over 5 years (2011-2016), by sampling bees directly on flowers or in flight using an entomological net, with 400 collected individuals/site/year. Bee species composition differed between post-mining ages and between sites. In all, we sampled 14.185 specimens and 236 bee species. The introduced Africanized Apis mellifera Linnaeus was the most frequent and abundant species, followed by Trigona spinipes and Psaenythia bergii Holmberg. Among habitats, the reforested area in initial phase showed lower richness and diversity in relation all others sample sites. Conversely, all indices were higher in forest remnants, middle phase II, and advanced phase reforested areas, reinforcing the importance of reforestation for conservation, notably endangered species, such as Oxytrigona sp., Schwarziana quadripunctata (Lepeletier), and the solitary species of the genus Hylaeus, all found in the restored areas. These results represent an important contribution for understanding the recovery of the bee fauna in restored mining habitats. The dataset reveals an interesting response in areas that were mined for shale extraction and are now undergoing different levels of restoration, suggesting that older reforested habitats have a higher probability of having a fully recovered bee community.

Global Warming, Advancing Bloom and Evidence for Pollinator Plasticity from Long-Term Bee Emergence Monitoring

Simple Summary

Common experience has it that natural seasonal events are earlier in some years and later in others. In temperate zones, these events often seem to be timed by some combination of winter chill hours followed by cumulative warmth, variables which vary with a year’s weather. Over the course of decades, monitored annual bloom dates of a variety of wildflower species varies over 4–8-week ranges. This study reports annual emergence dates of four wild species of ground-nesting bees recorded over 12–24 years. Their first emergence ranged over 4–6 weeks, comparable to wildflowers and in part relatable to the same thermal cues used by plants. Global warming is advancing seasonal events, notably flowering, but it appears that native bees have the phenological flexibility to maintain their floral associations and critical pollination services both in wild and agricultural settings.

Abstract

Global warming is extending growing seasons in temperate zones, yielding earlier wildflower blooms. Short-term field experiments with non-social bees showed that adult emergence is responsive to nest substrate temperatures. Nonetheless, some posit that global warming will decouple bee flight and host bloom periods, leading to pollination shortfalls and bee declines. Resolving these competing scenarios requires evidence for bees’ natural plasticity in their annual emergence schedules. This study reports direct observations spanning 12–24 years for annual variation in the earliest nesting or foraging activities by 1–4 populations of four native ground-nesting bees: Andrena fulva (Andrenidae), Halictus rubicundus (Halictidae), Habropoda laboriosa and Eucera (Peponapis) pruinosa (Apidae). Calendar dates of earliest annual bee activity ranged across 25 to 45 days, approximating reported multi-decadal ranges for published wildflower bloom dates. Within a given year, the bee H. rubicundus emerged in close synchrony at multiple local aggregations, explicable if meteorological factors cue emergence. Emergence dates were relatable to thermal cues, such as degree day accumulation, soil temperature at nesting depth, and the first pulse of warm spring air temperatures. Similar seasonal flexibilities in bee emergence and wildflower bloom schedules bodes well for bees and bloom to generally retain synchrony despite a warming climate. Future monitoring studies can benefit from several simple methodological improvements.

Seasonality of floral resources in relation to bee activity in agroecosystems

The contribution of wild insects to crop pollination is becoming increasingly important as global demand for crops dependent on animal pollination increases. If wild insect populations are to persist in agricultural landscapes, there must be sufficient resources over time and space. The temporal, within-season component of floral resource availability has rarely been investigated, despite growing recognition of its likely importance for pollinator populations. Here, we examined the visitation rates of common bee genera and the spatiotemporal availability of floral resources in agroecosystems over one season to determine whether local wild bee activity was limited by landscape floral resource abundance, and if so, whether it was limited by the present or past abundance of landscape floral resources. Visitation rates and landscape floral resources were measured in 27 agricultural sites in Ontario and Québec, Canada, across four time periods and three spatial scales. Floral resources were determined based on species-specific floral volume measurements, which we found to be highly correlated with published measurements of nectar sugar mass and pollen volume. Total floral volume at varying spatial scales predicted visits for commonly observed bee genera. We found Lasioglossum and Halictus visits were highest in landscapes that provided either a stable or increasing amount of floral resources over the season. Andrena visits were highest in landscapes with high floral resources at the start of the season, and Bombus visits appeared to be positively related to greater cumulative seasonal abundance of floral resources. These findings together suggest the importance of early-season floral resources to bees. Megachile visits were negatively associated with the present abundance of floral resources, perhaps reflecting pollinator movement or dilution. Our research provides insight into how seasonal fluctuations in floral resources affect bee activity and how life history traits of bee genera influence their responses to food availability within agroecosystems.

Global Patterns and Drivers of Bee Distribution

Insects are the focus of many recent studies suggesting population declines, but even invaluable pollination service providers such as bees lack a modern distributional synthesis. Here, we combine a uniquely comprehensive checklist of bee species distributions and >5,800,000 public bee occurrence records to describe global patterns of bee biodiversity. Publicly accessible records are sparse, especially from developing countries, and are frequently inaccurate throughout much of the world, consequently suggesting different biodiversity patterns from checklist data. Global analyses reveal hotspots of species richness, together generating a rare bimodal latitudinal richness gradient, and further analyses suggest that xeric areas, solar radiation, and non-forest plant productivity are among the most important global drivers of bee biodiversity. Together, our results provide a new baseline and best practices for studies on bees and other understudied invertebrates.

Bee species checklist of the San Francisco Peaks, Arizona

Background

Here we present a checklist of the bee species found on the C. Hart Merriam elevation gradient along the San Francisco Peaks in northern Arizona. Elevational gradients can serve as natural proxies for climate change, replacing time with space as they span multiple vegetation zones over a short geographic distance. Describing the distribution of bee species along this elevation gradient will help predict how bee communities might respond to changing climate. To address this, we initiated an inventory associated with ecological studies on pollinators that documented bees on the San Francisco Peaks. Sample sites spanned six life zones (vegetation zones) on the San Francisco Peaks from 2009 to 2019. We also include occurrence data from other studies, gathered by querying the Symbiota Collection of Arthropods Network (SCAN) portal covering the San Francisco Peaks region (hereafter referred to as "the Peaks").

New information

Our checklist reports 359 bee species and morphospecies spanning five families and 46 genera that have been collected in the Peaks region. Prior to our concerted sampling effort there were records for 155 bee species, yet there has not been a complete list of bee species inhabiting the Peaks published to date. Over a 10-year period, we documented an additional 204 bee species inhabiting the Peaks. Our study documents range expansions to northern Arizona for 15 species. The majority of these are range expansions from either southern Arizona, southern Utah, or the Rocky Mountain region of Colorado. Nine species are new records for Arizona, four of which are the southernmost record for that species. An additional 15 species are likely undescribed.

More Than Meets the Eye? The Role of Annual Ornamental Flowers in Supporting Pollinators

Ornamental flowers are commonly planted in urban and suburban areas to provide foraging resources for pollinator populations. However, their role in supporting broad pollinator biodiversity is not well established as previous studies have been conducted in urban landscapes with pollinator communities that are distinct from those in natural systems. We observed pollinator visitation patterns to five ornamental annual plant genera and their cultivars over multiple years at two semi-natural sites in Pennsylvania to understand their potential for supporting diverse pollinator communities. There was significant variation in visitor abundance and diversity by season and year for many annual ornamental cultivars. Within some genera, cultivars had similar visitor abundance, diversity, and main visitor taxa, while cultivars in other genera varied greatly in these measures. We observed only polylectic (pollen generalist) bee species visiting annual ornamentals, despite the presence of oligolectic (pollen specialist) bee species in the background population. We conclude that the attractiveness of annual ornamental plants likely depends on both cultivar characteristics and environmental context. While their role in supporting complex pollinator populations is limited both based on the number of and dietary breadth of the species they support, ornamental plants may nonetheless provide long-lasting supplemental foraging resources for the generalist pollinator communities characteristic of urban and suburban environments.

A comparative study of the pharyngeal plate of Apoidea (Hymenoptera: Aculeata), with implications for the understanding of phylogenetic relationships of bees

The pharyngeal plate is a morphological complex with extensive anatomical variation among bees and, therefore, potential as a source of phylogenetic information. The pharyngeal plate of bees is divided into four morphologically distinct regions: sitophore, hypopharyngeal lobe, pharyngeal rods, and median oral plate. In this work we illustrate and document in detail for the first time the pharyngeal plate of 43 bee species, providing descriptions of the morphological variation and contrasting these findings with representatives of apoid wasps (Crabronidae and Sphecidae). We evaluate and discuss the potential of this structure as a rich source of morphological information in the context of bee phylogeny and any research potentially impacted by comparative morphological data. The shape of the hypopharyngeal lobe is highly variable among suprageneric taxa of bees and can be readily employed to characterise taxa at various levels. We argue that the global patterns in the variation of the pharyngeal plate can provide information for phylogenetic inference within bees and constructed and coded 10 characters that encompass the most noticeable morphological differences discussed herein.

Does body size predict the buzz-pollination frequencies used by bees?

Body size is an important trait linking pollinators and plants. Morphological matching between pollinators and plants is thought to reinforce pollinator fidelity, as the correct fit ensures that both parties benefit from the interaction. We investigated the influence of body size in a specialized pollination system (buzz-pollination) where bees vibrate flowers to release pollen concealed within poricidal stamens. Specifically, we explored how body size influences the frequency of buzz-pollination vibrations. Body size is expected to affect frequency as a result of the physical constraints it places on the indirect flight muscles that control the production of floral vibrations. Larger insects beat their wings less rapidly than smaller-bodied insects when flying, but whether similar scaling relationships exist with floral vibrations has not been widely explored. This is important because the amount of pollen ejected is determined by the frequency of the vibration and the displacement of a bee's thorax. We conducted a field study in three ecogeographic regions (alpine, desert, grassland) and recorded flight and floral vibrations from freely foraging bees from 27 species across four families. We found that floral vibration frequencies were significantly higher than flight frequencies, but never exceeded 400 Hz. Also, only flight frequencies were negatively correlated with body size. As a bee's size increased, its buzz ratio (floral frequency/flight frequency) increased such that only the largest bees were capable of generating floral vibration frequencies that exceeded double that of their flight vibrations. These results indicate size affects the capacity of bees to raise floral vibration frequencies substantially above flight frequencies. This may put smaller bees at a competitive disadvantage because even at the maximum floral vibration frequency of 400 Hz, their inability to achieve comparable thoracic displacements as larger bees would result in generating vibrations with lower amplitudes, and thus less total pollen ejected for the same foraging effort.

Phylogenomic analysis of Apoidea sheds new light on the sister group of bees

Background

Apoid wasps and bees (Apoidea) are an ecologically and morphologically diverse group of Hymenoptera, with some species of bees having evolved eusocial societies. Major problems for our understanding of the evolutionary history of Apoidea have been the difficulty to trace the phylogenetic origin and to reliably estimate the geological age of bees. To address these issues, we compiled a comprehensive phylogenomic dataset by simultaneously analyzing target DNA enrichment and transcriptomic sequence data, comprising 195 single-copy protein-coding genes and covering all major lineages of apoid wasps and bee families.

Results

Our compiled data matrix comprised 284,607 nucleotide sites that we phylogenetically analyzed by applying a combination of domain- and codon-based partitioning schemes. The inferred results confirm the polyphyletic status of the former family “Crabronidae”, which comprises nine major monophyletic lineages. We found the former subfamily Pemphredoninae to be polyphyletic, comprising three distantly related clades. One of them, Ammoplanina, constituted the sister group of bees in all our analyses. We estimate the origin of bees to be in the Early Cretaceous (ca. 128 million years ago), a time period during which angiosperms rapidly radiated. Finally, our phylogenetic analyses revealed that within the Apoidea, (eu)social societies evolved exclusively in a single clade that comprises pemphredonine and philanthine wasps as well as bees.

Conclusion

By combining transcriptomic sequences with those obtained via target DNA enrichment, we were able to include an unprecedented large number of apoid wasps in a phylogenetic study for tracing the phylogenetic origin of bees. Our results confirm the polyphyletic nature of the former wasp family Crabonidae, which we here suggest splitting into eight families. Of these, the family Ammoplanidae possibly represents the extant sister lineage of bees. Species of Ammoplanidae are known to hunt thrips, of which some aggregate on flowers and feed on pollen. The specific biology of Ammoplanidae as predators indicates how the transition from a predatory to pollen-collecting life style could have taken place in the evolution of bees. This insight plus the finding that (eu)social societies evolved exclusively in a single subordinated lineage of apoid wasps provides new perspectives for future comparative studies.

Electronic supplementary material

The online version of this article (10.1186/s12862-018-1155-8) contains supplementary material, which is available to authorized users.

A new species of the carpenter bee genus Xylocopa from the Sarawat Mountains in southwestern Saudi Arabia (Hymenoptera, Apidae)

A new species of the carpenter bee genus Xylocopa Latreille (Xylocopinae: Xylocopini) is described and figured from two localities in southern Saudi Arabia. Xylocopa (Koptortosoma) sarawatica Engel, sp. n. is a relatively small species similar to the widespread X.pubescens Spinola, but differs in the extent of maculation in males, setal coloration of both sexes, and male terminalia. A revised key to the species of Xylocopa in Saudi Arabia is provided.

An Early Miocene bumble bee from northern Bohemia (Hymenoptera, Apidae)

A new species of fossil bumble bee (Apinae: Bombini) is described and figured from Early Miocene (Burdigalian) deposits of the Most Basin at the Bílina Mine, Czech Republic. Bombus trophoniussp. n., is placed within the subgenus Cullumanobombus Vogt and distinguished from the several species groups therein. The species is apparently most similar to the Nearctic B. (Cullumanobombus) rufocinctus Cresson, the earliest-diverging species within the clade and the two may be related only by symplesiomorphies. The age of the fossil is in rough accordance with divergence estimations for Cullumanobombus.

Disturbance-mediated heterogeneity drives pollinator diversity in boreal managed forest ecosystems

Intensive forest management, together with fire suppression, have decreased structural complexity and altered dynamics of boreal forests profoundly. Such management threatens forest biodiversity and can reduce the provision of ecosystem services. Although the importance of ecosystem services is widely acknowledged, conservation strategies are hindered by poor knowledge about diversity patterns of service provider species as well as on mechanisms affecting these assemblages at different spatial and temporal scales. In this study, we assessed the effect of disturbance management on forest pollinator communities. To do so, we used a large-scale ecological experiment conducted in the year 2000, where forest complexity was manipulated with different harvest regimes and prescribed fire. Results were consistent with a positive response of pollinators to increasing habitat heterogeneity driven by past disturbances. Harvested sites harbored a diverse pollinator community, and showed higher spatial and temporal turnover in species richness. Conversely, old-growth forest communities were a nested subset of harvested sites and contained half of their total diversity. Variation in community composition (β diversity) was primarily affected by species temporal turnover. Throughout the season, β diversity was controlled by fire and harvesting legacies, which provide environmental heterogeneity in the form of flowering and nesting resources over space and time. Conservation strategies may undervalue ecosystem services in dynamic, naturally disturbance-driven, landscapes when relying solely on undisturbed forests areas. However, maintaining natural dynamics in early successional forests, by emulating natural disturbances at harvesting, hold promise for the conservation of both biodiversity and ecosystem services in boreal forests.

USBombus, a database of contemporary survey data for North American Bumble Bees (Hymenoptera, Apidae, Bombus) distributed in the United States

Background

Bumble bees (Hymenoptera: Apidae, Bombus) are pollinators of wild and economically important flowering plants. However, at least four bumble bee species have declined significantly in population abundance and geographic range relative to historic estimates, and one species is possibly extinct. While a wealth of historic data is now available for many of the North American species found to be in decline in online databases, systematic survey data of stable species is still not publically available. The availability of contemporary survey data is critically important for the future monitoring of wild bumble bee populations. Without such data, the ability to ascertain the conservation status of bumble bees in the United States will remain challenging.

New information

This paper describes USBombus, a large database that represents the outcomes of one of the largest standardized surveys of bumble bee pollinators (Hymenoptera, Apidae, Bombus) globally. The motivation to collect live bumble bees across the United States was to examine the decline and conservation status of Bombusaffinis, B.occidentalis, B.pensylvanicus, and B.terricola. Prior to our national survey of bumble bees in the United States from 2007 to 2010, there have only been regional accounts of bumble bee abundance and richness. In addition to surveying declining bumble bees, we also collected and documented a diversity of co-occuring bumble bees. However we have not yet completely reported their distribution and diversity onto a public online platform. Now, for the first time, we report the geographic distribution of bumble bees reported to be in decline (Cameron et al. 2011), as well as bumble bees that appeared to be stable on a large geographic scale in the United States (not in decline). In this database we report a total of 17,930 adult occurrence records across 397 locations and 39 species of Bombus detected in our national survey. We summarize their abundance and distribution across the United States and association to different ecoregions. The geospatial coverage of the dataset extends across 41 of the 50 US states, and from 0 to 3500 m a.s.l. Authors and respective field crews spent a total of 512 hours surveying bumble bees from 2007 to 2010. The dataset was developed using SQL server 2008 r2. For each specimen, the following information is generally provided: species, name, sex, caste, temporal and geospatial details, Cartesian coordinates, data collector(s), and when available, host plants. This database has already proven useful for a variety of studies on bumble bee ecology and conservation. However it is not publicly available. Considering the value of pollinators in agriculture and wild ecosystems, this large database of bumble bees will likely prove useful for investigations of the effects of anthropogenic activities on pollinator community composition and conservation status.

Systematics and biology of Xylocopa subgenus Schonnherria (Hymenoptera, Apidae) in Argentina

Biological information on the species of the large carpenter bee XylocopasubgenusSchonnherria occurring in Argentina is revised. Based on the appraisal of museum specimens, the study of type material, and field surveys conducted across 15 provinces between 2007 and 2011, the following seven species are recognized for the country: Xylocopabambusae Schrottky, Xylocopachrysopoda Schrottky, Xylocopamacrops Lepeletier de Saint Fargeau, Xylocopasimillima Smith Xylocopasplendidula Lepeletier de Saint Fargeau, Xylocopapulchra Smith, and Xylocopaviridis Smith. Previous literature records of Xylocopadimidiata Latreille, Xylocopasubcyanea Pérez, and Xylocopavarians Smith for the province of Misiones appear to have been misidentified specimens, although the presence of these species in Argentina cannot be entirely ruled out given the proximity of this province to Brazil and Paraguay where they occur; Xylocopaboops Maidl was described from a male specimen with unusually enlarged eyes and is newly synonymized under Xylocopamacrops. Males and females of all species are diagnosed, described, and figured, including details of the male genitalia. Taxonomic comments, data on the geographical distribution and nesting substrates, and identification keys to all Argentinean species of Schonnherria are provided. The nesting biologies of Xylocopasplendidula and Xylocopaviridis are documented.

Rediscovered parasitism of Andrena savignyi Spinola (Hymenoptera, Andrenidae) by Stylops (Strepsiptera, Stylopidae) and revised taxonomic status of the parasite

Parasitism of Andrena (Suandrena) savignyi Spinola (Hymenoptera: Andrenidae) by Stylops Kirby (Strepsiptera: Stylopidae) has been recorded only once, and from an individual collected in Egypt almost a century ago, with the parasite described as Stylops savignyi Hofeneder. The recent rediscovery of this Stylops from an individual of Andrena savignyi permits a reinterpretation of the species and its affinities among other Stylops. The bee was collected at flowers of Zilla spinosa (Turra) Prantl. (Brassicaceae) in Amariah, Riyadh, Kingdom of Saudi Arabia. Based on DNA barcode sequences from material sampled across Africa, Asia, and Europe, it is apparent that Stylops savignyi is conspecific with Stylops nassonowi Pierce, and we accordingly synonymize this name (syn. n.), with the latter representing the senior and valid name for the species. A differential diagnosis is provided for Stylops nassonowi and the morphology of the female is described, as well as the first instars.

AnthWest, occurrence records for wool carder bees of the genus Anthidium (Hymenoptera, Megachilidae, Anthidiini) in the Western Hemisphere

This paper describes AnthWest, a large dataset that represents one of the outcomes of a comprehensive, broadly comparative study on the diversity, biology, biogeography, and evolution of Anthidium Fabricius in the Western Hemisphere. In this dataset a total of 22,648 adult occurrence records comprising 9657 unique events are documented for 92 species of Anthidium, including the invasive range of two introduced species from Eurasia, A. oblongatum (Illiger) and A. manicatum (Linnaeus). The geospatial coverage of the dataset extends from northern Canada and Alaska to southern Argentina, and from below sea level in Death Valley, California, USA, to 4700 m a.s.l. in Tucumán, Argentina. The majority of records in the dataset correspond to information recorded from individual specimens examined by the authors during this project and deposited in 60 biodiversity collections located in Africa, Europe, North and South America. A fraction (4.8%) of the occurrence records were taken from the literature, largely California records from a taxonomic treatment with some additional records for the two introduced species. The temporal scale of the dataset represents collection events recorded between 1886 and 2012. The dataset was developed employing SQL server 2008 r2. For each specimen, the following information is generally provided: scientific name including identification qualifier when species status is uncertain (e.g. “Questionable Determination” for 0.4% of the specimens), sex, temporal and geospatial details, coordinates, data collector, host plants, associated organisms, name of identifier, historic identification, historic identifier, taxonomic value (i.e., type specimen, voucher, etc.), and repository. For a small portion of the database records, bees associated with threatened or endangered plants (~ 0.08% of total records) as well as specimens collected as part of unpublished biological inventories (~17%), georeferencing is presented only to nearest degree and the information on floral host, locality, elevation, month, and day has been withheld. This database can potentially be used in species distribution and niche modeling studies, as well as in assessments of pollinator status and pollination services. For native pollinators, this large dataset of occurrence records is the first to be simultaneously developed during a species-level systematic study.

A new species of Megachile Latreille subgenus Megachiloides (Hymenoptera, Megachilidae)

A new species of leafcutter bee, Megachile (Megachiloides) chomskyi, is described from Texas, United States. Megachile chomskyi is one of the four known species of the oenotherae species group of Megachiloides, all members sharing the long tongue, and is most similar to Megachile (Megachiloides) amica Cresson. Like other members of the oenotherae species group, this species probably shows oligolecty with Onagraceae (Evening-Primrose Family). A diagnosis, full description of both sexes and a key to the species of the oenotherae species group are provided.

The melectine bee genera Brachymelecta and Sinomelecta (Hymenoptera, Apidae)

The enigmatic, cleptoparasitic bee genera Brachymelecta Linsley and Sinomelecta Baker (Apinae: Melectini) are redescribed, each represented by a single species which has not been reencountered since capture of the type series ca. 1878 and 1900, respectively. Both genera are the only melectines to possess two submarginal cells in the forewing but are otherwise wholly dissimilar. Brachymelecta mucida (Cresson), a species known only from the male holotype collected in “Nevada”, is newly described and figured, including the first account of the hidden sterna and genitalia. Sinomelecta oreina Baker is similarly described and figured based on the holotype male and paratype female, apparently collected from the eastern Tibetan Plateau. Both genera are valid and from the available data do not appear to represent merely autapomorphic forms of Melecta Latreille. Indeed, the terminalia of Sinomelecta oreina are in some respects more similar to those of species of Thyreus Panzer.

Three new cryptic species of Euglossa from Brazil (Hymenoptera, Apidae)

Three new species of orchid bees are described and figured from the Amazon and Atlantic forests of Brazil. Euglossa clausisp. n., Euglossa moratoisp. n., and Euglossa pepeisp. n. are distinguished from their close congeners Euglossa crassipunctata Moure, Euglossa parvula Dressler, and Euglossa sapphirina Moure, previously placed in the subgenus Euglossa (Glossurella) Dressler, 1982, a demonstrably paraphyletic assemblage requiring serious reconsideration. Their affinities with related species are discussed and pertinent characters are figured.

The apid cuckoo bees of the Cape Verde Islands (Hymenoptera, Apidae)

The apid cuckoo bees of the Cape Verde Islands (Republic of Cape Verde) are reviewed and five species recognized, representing two genera. The ammobatine genus Chiasmognathus Engel (Nomadinae: Ammobatini), a specialized lineage of cleptoparasites of nomioidine bees is recorded for the first time. Chiasmognathus batelkaisp. n. is distinguished from mainland African and Asian species. The genus Thyreus Panzer (Apinae: Melectini) is represented by four species – Thyreus denoliisp. n., Thyreus batelkaisp. n., Thyreus schwarzisp. n., and Thyreus aistleitnerisp. n. Previous records of Thyreus scutellaris (Fabricius) from the islands were based on misidentifications.

A new species of Chalicodoma from Saudi Arabia with modified facial setae (Hymenoptera, Megachilidae)

Some bees and pollen wasps have independently evolved simple, stiff, erect, apically-curved, curly or hooked facial setae as adaptations to collect pollen from nototribic flowers. A distinctive new species of Chalicodoma Lepeletier de Saint Fargeau subgenus Pseudomegachile Friese from Saudi Arabia with such morphological adaptations, Chalicodoma riyadhensesp. n., is described and figured. The species was captured visiting flowers of Blepharis ciliaris (L.) (Acanthaceae). The occurrence of modified facial setae is documented and discussed for the first time in eight other species of Pseudomegachile, and a key to the genera and subgenera of Megachilini currently confirmed for Saudi Arabia is provided.

The large carpenter bees of central Saudi Arabia, with notes on the biology of Xylocopa sulcatipes Maa (Hymenoptera, Apidae, Xylocopinae)

The large carpenter bees (Xylocopinae, Xylocopa Latreille) occurring in central Saudi Arabia are reviewed. Two species are recognized in the fauna, Xylocopa (Koptortosoma) aestuans (Linnaeus) and Xylocopa (Ctenoxylocopa) sulcatipes Maa. Diagnoses for and keys to the species of these prominent components of the central Saudi Arabian bee fauna are provided to aid their identification by pollination researchers active in the region. Females and males of both species are figured and biological notes provided for Xylocopa sulcatipes. Notes on the nesting biology and ecology of Xylocopa sulcatipes are appended. As in studies for this species from elsewhere, nests were found in dried stems of Calotropis procera (Aiton) (Asclepiadaceae) and Phoenix dactylifera L. (Arecaceae).

A new Chlerogelloides from northeastern Brazil and French Guiana, with a key to the species (Hymenoptera, Halictidae)

A third species of the rare augochlorine bee genus Chlerogelloides Engel et al. (Halictinae, Augochlorini) is described and figured. Chlerogelloides nexosasp. n. is most similar to the type species, Chlerogelloides femoralis Engel et al., in that both have modified midlegs in the males. The former, however, can be distinguished on the basis of its terminalia, which in some respects more closely resembles those of Chlerogelloides simplex Engel and Brooks. Brief comments on the secondary features of males and relationships of the genus are provided. A key to the species of the genus is provided and floral records of Cordia nodosa Lam. (Boraginaceae) and Gonzalagunia dicocca Cham. & Schltdl. (Rubiaceae) are noted.

A new wild, pollinating bee species of the genus Tetraloniella from the Arabian Peninsula (Hymenoptera, Apidae)

A new species of the eucerine bee genus Tetraloniella Ashmead (Apinae: Eucerini) is described and figured from central Saudi Arabia and Qatar. Tetraloniella (Tetraloniella) persiciformissp. n. is distinguished on the basis of coloration, integumental sculpturing, male metafemoral structure, and male terminalia. A floral record of Pulicaria undulata (L.) C.A. Mey. (Compositae) is noted for some of the material. Females superficially resemble those of Tarsalia persica (Warncke) (Ancylaini) in overall coloration but can be distinguished by the typical generic and tribal characters.

New species of the Eastern Hemisphere genera Afroheriades and Noteriades (Hymenoptera, Megachilidae), with keys to species of the former

New species of the rarely encountered megachilid genera Afroheriades Peters from South Africa, Afroheriades hyalinussp. n., and Noteriades Cockerell from Myanmar and Thailand, Noteriades jenniferaesp. n. and Noteriades spinosussp. n., are described and illustrated. The species are described to make their names available for forthcoming publications on phylogenetic studies of the family Megachilidae. Taxonomic notes and a comparative diagnosis for each genus are presented. Afroheriades hennigi (Peters) and Afroheriades reicherti (Brauns) are new junior synonyms of Afroheriades dolichocephalus (Friese). A key to the known species of Afroheriades is provided.

Euglossa williamsi, a new species of orchid bee from the Amazon Basin of Ecuador and Peru, with notes on its taxonomic association and biogeography (Hymenoptera, Apidae)

Euglossa williamsisp. n. is here described from the lowland Amazonian region in Ecuador and Peru, and as part of a small species assemblage within Euglossa consisting of Euglossa dodsoni Moure and Euglossa obtusa Dressler. An identification key to the males of the group is provided plus detailed figures of the new species and representative illustrations for the others. A brief discussion of the taxonomic and biogeographical implications of the new species is provided. New records in Honduras and Nicaragua are provided for the related Euglossa dodsoni.

Leioproctus rosellae sp. n., the first record of the genus from northern South America (Hymenoptera, Colletidae)

Leioproctus Smith is a diverse colletine genus found in the Australian region and primarily temperate areas of South America. A new species of Leioproctus subgenus Perditomorpha Ashmead, Leioproctus rosellae Gonzalez, sp. n., from a tropical dry forest of the Caribbean coast of Colombia is described and figured. This is the first record of the genus from northern South America.

A new species of Chilicola from Bahia, Brazil (Hymenoptera, Colletidae), with a key to the species of the megalostigma group

The bee genus Chilicola Spinola (Xeromelissinae) is recorded from the State of Bahia, Brazil for the first time, based on a new species of the megalostigma group of the subgenus Hylaeosoma Ashmead. Chilicola (Hylaeosoma) kevanisp. n. is described and figured from males collected in Wesceslau Guimarães, Bahia. The species can be distinguished on the basis of coloration, size, integumental sculpturing, and structure of the hidden metasomal sterna and genitalia. A revised key to the species of the megalostigma group is provided.

A new species of Centris ( Centris) (Fabricius) from northeastern Brazil, with taxonomic notes on C. ( C.) pulchra Moure, Oliveira & Viana (Hymenoptera, Apidae)

We describe a new species of the bee genus Centris, Centris (Centris) byrsonimae Mahlmann & Oliveira sp. n., whose name has appeared as a nomen nudum in the literature since 1985. Further, a new species group of Centris s.str. is proposed, the pulchra group, based on morphological characters, which comprises the species Centris pulchra Moure, Oliveira & Viana, 2003 and Centris byrsonimaesp. n..Based on information from specimen labels studied and data from the literature, a list of plant species visited by the pulchra group is presented. The male genitalia and hidden metasomal sterna 7 and 8 of Centris pulchra are described for the first time. Typographic errors pertaining to the paratype labels reported in the original description of Centris pulchra are corrected. One female paratype of Centris pulchra is designated herein as a paratype of Centris byrsonimaesp. n. An updated list of species of Centris s.str. from northeastern Brazil is provided including references about geographic distributions as well as an identification key to the pulchra species group.

Revision of the orchid bee subgenus Euglossella (Hymenoptera, Apidae), Part I, The decorata species group

Euglossella, one of the most distinctive subgenera of orchid bees of the genus Euglossa, is composed of two characteristic assemblages of species, one of them comprising bees bearing the strongly metallic integument trademark of the genus (viridis species group), and the other consisting of bees with a brown integument shaded with metallic iridescence (decorata species group). Here we provide the first of two parts of a revision of Euglossella, providing diagnostic definitions for the subgenus, the decorata species group, and all the species included therein. Six species are included in the decorata group, one new: Euglossa (Euglossella) aurantia, sp. n.; Euglossa (Euglossella) apiformis Schrottky, resurrected status; Euglossa (Euglossella) decorata Smith, revised status; Euglossa (Euglossella) singularis Mocsáry, revised status; Euglossa (Euglossella) cosmodora Hinojosa-Díaz and Engel; and Euglossa (Euglossella) perpulchra Moure and Schlindwein. Euglossa meliponoides Ducke and Euglossa urarina Hinojosa-Díaz and Engel are newly synonymized under Euglossa decorata, Euglossa decorata ruficauda Cockerell is synonymized under Euglossa singularis, and a neotype is designated for Euglossa apiformis.

Taxonomic notes on the small resin bees Hypanthidioides subgenus Michanthidium (Hymenoptera, Megachilidae)

As part of ongoing investigations on anthidiine bees, the type of Anthidium albitarse Friese was found to be conspecific with one of the two species of the small resin bees Hypanthidioides subgenus Michanthidium. The new combination, Hypanthidioides (Michanthidium) albitarsis, is the oldest name, resulting in Gnathanthidium sakagamii Urban as a new junior synonym. The previously unknown male of the second species, Hypanthidioides ferrugineus, is described and figured, including the genitalic structure and associated sterna. Males and females of Hypanthidioides ferrugineus have been collected from flowers of Cuphea sp. (Lythraceae).

The indigenous honey bees of Saudi Arabia (Hymenoptera, Apidae, Apis mellifera jemenitica Ruttner): Their natural history and role in beekeeping

Apis mellifera jemenitica Ruttner (= yemenitica auctorum: videEngel 1999) has been used in apiculture throughout the Arabian Peninsula since at least 2000 BC. Existing literature demonstrates that these populations are well adapted for the harsh extremes of the region. Populations of Apis mellifera jemenitica native to Saudi Arabia are far more heat tolerant than the standard races often imported from Europe. Central Saudi Arabia has the highest summer temperatures for the Arabian Peninsula, and it is in this region where only Apis mellifera jemenitica survives, while other subspecies fail to persist. The indigenous race of Saudi Arabia differs from other subspecies in the region in some morphological, biological, and behavioral characteristics. Further taxonomic investigation, as well as molecular studies, is needed in order to confirm whether the Saudi indigenous bee populations represent a race distinct from Apis mellifera jemenitica, or merely an ecotype of this subspecies.

Callosphecodes, a little-known bee (Hymenoptera, Halictidae, Sphecodes)

Callosphecodes Friese, 1909, a synonym or perhaps subgenus of Sphecodes Latreille, 1804, is known on the basis of one female of Sphecodes ralunensis (Friese, 1909)from New Britain and one female and one male of a similar species, Sphecodes manskii (Rayment, 1935) from northeastern Australia. The male is here described for the first time and the females of the two species are compared for the first time. In spite of considerable collecting, only these three specimens have appeared in over a century. Descriptions and illustrations are provided.

Andinopanurgus, a new Andean subgenus of Protandrena (Hymenoptera, Andrenidae)

A new subgenus of Protandrena Cockerell (Panurginae: Protandrenini) from South America, Andinopanurgus Gonzalez & Engel, subgen. n., is described and figured for distinctive species of the genus occurring at mid- and high elevations in the Andes from Venezuela to Peru (1100-3400 m). In addition to the distribution, the subgenus is easily distinguished from other subgenera by a unique combination of morphological characters in both sexes, especially in the hidden sterna and genitalia of the male. Protandrena amyaesp. n., and Protandrena femoralissp. n., are also described and figured from the Ecuadorian and Peruvian Andes. New geographical records and a key to the species are also provided.

The identity of the Neotropical stingless bee Frieseomelitta meadewaldoi (Cockerell, 1915) (Hymenoptera, Apidae)

A new study of a surviving syntype of Trigona meadewaldoi Cockerell, 1915, was undertaken and several widely employed names for Neotropical stingless bees recognized as junior synonyms. A lectotype is designated for Trigona meadewaldoi and the following new synonymies established: Tetragona francoi Moure, 1946, and Trigona (Frieseomelitta) freiremaiai Moure, 1963. These nomenclatural matters are here settled and the species thoroughly characterized in advance of a forthcoming phylogenetic consideration of the genus Frieseomelitta von Ihering, 1912.

Two new species of Paratrigona and the male of Paratrigona ornaticeps (Hymenoptera, Apidae)

Two distinctive new species of the Neotropical stingless bee genus Paratrigona Schwarz from Ecuador and Paraguay are described and figured. The Ecuadorian species, Paratrigona scapisetosasp. n.,belongs to the haeckeli-lineatifrons group and is easily distinguished from its congeners by the unique shape and pubescence of the antennal scape, which is distinctly convex on its outer margin and bears thick, long, simple hairs along its inner margin. The Paraguayan species, Paratrigona wasbauerisp. n.,belongs to the lineata group and is easily distinguished by the pattern of body pubescence in both sexes and male genitalic characters. The male of the Mesoamerican species Paratrigona ornaticeps (Schwarz) is described and figured. New geographical records for Paratrigona impunctata and Paratrigona opaca, and an updated key to the haeckeli-lineatifrons and lineata species groups are provided.

Alocanthedon, a new subgenus of Chalicodoma from Southeast Asia (Hymenoptera, Megachilidae)

A new subgenus, Alocanthedon Engel and Gonzalez subgen. n., is described for five species of unusual Southeast Asian bees in the genus Chalicodoma Lepeletier de Saint Fargeau (Megachilinae: Megachilini). The subgenus is most noteworthy for the deep postgenal depression or furrow in males (bordered outwardly near the base of the mandible by a protuberant, thick lamella) and the presence of a dense patch of black setae posteriorly in the forewing medial cell (except in one species) [resembling the dense patch of setae among the submarginal cells of Thrinchostoma Saussure (Halictidae: Halictinae: Halictini)]. The subgenus is characterized and distinguished from the related Callomegachile Michener. A key to the following five species presently included in the subgenus is provided: Chalicodoma aterrimum (Smith), Chalicodoma atratiforme (Meade-Waldo) comb. n., Chalicodoma memecylonae Engel sp. n., Chalicodoma odontophorum Engel sp. n., and Chalicodoma apoicola Engel sp. n.Chalicodoma (Callomegachile) atratiforme sininsulae (Cockerell) is newly placed in synonymy with C. (C.) fulvipenne (Smith). Species have been collected from Memecylaceae (Myrtales) and Fabaceae (Fabales). The phylogenetic relationships of Alocanthedon among other Megachilini are briefly elaborated upon.