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Societal Impact Statement: The family Orchidaceae is renowned for its reliance on specialized pollinators and mycorrhizal symbioses. This study examined how the nonphotosynthetic orchid Gastrodia elata thrives on the dim forest floor, focusing on its pollination biology, particularly the chemical properties of pseudopollen and reproductive assurance mechanisms. It was found that G. elata mainly relies on Lasioglossum bees, attracted by its starch‐rich pseudopollen. Additionally, G. elata in the studied population can produce fruit through agamospermy (seeds from unfertilized ovules). Overall, the findings reveal that G. elata relies on fungi for nutrition and employs reproductive strategies such as mimicking pollen to attract bees and resorting to asexual reproduction when pollinators are scarce. Summary: Mycoheterotrophy is an adaptation that allows survival in environments with low irradiance and minimal competition from autotrophic plants. However, such environments can negatively impact bee pollination, as most bees prefer open habitats. Despite this, the mycoheterotrophic orchid Gastrodia elata is known to rely on Lasioglossum bees for pollination.We investigated the reproductive biology of G. elata to understand how it overcomes pollinator limitation. Our research focused on the chemical composition and anatomical basis of G. elata pseudopollen (a substance that mimics pollen and may facilitate pollination), based on micromorphological and nutritional analyses, as well as observations of pollinator behavior. Additionally, we explored the potential presence of autogamy or agamospermy as mechanisms for reproductive assurance.The pseudopollen in G. elata originates from the disintegration of the adaxial parenchymatous tissue of the callus and is rich in starch. This contrasts with pseudopollen in most orchids, which typically originates from lip hairs and whose potential attractant is protein. Lasioglossum bees pollinating G. elata visit multiple flowers and actively collect pseudopollen. Furthermore, agamospermy serves as a reproductive safeguard in shaded habitats where insect‐mediated pollination is infrequent, at least in the investigated population.Our findings suggest that Gastrodia elata pseudopollen plays an important role in enhancing insect‐mediated pollination, particularly in relatively open habitats, while agamospermy ensures fruit set in shaded environments of the investigated population. Both pseudopollen production and agamospermy likely help overcome the pollination constraints posed by the mycoheterotrophic lifestyle. [ABSTRACT FROM AUTHOR]

Societal Impact Statement The family Orchidaceae is renowned for its reliance on specialized pollinators and mycorrhizal symbioses. This study examined how the nonphotosynthetic orchid Gastrodia elata thrives on the dim forest floor, focusing on its pollination biology, particularly the chemical properties of pseudopollen and reproductive assurance mechanisms. It was found that G. elata mainly relies on Lasioglossum bees, attracted by its starch‐rich pseudopollen. Additionally, G. elata in the studied population can produce fruit through agamospermy (seeds from unfertilized ovules). Overall, the findings reveal that G. elata relies on fungi for nutrition and employs reproductive strategies such as mimicking pollen to attract bees and resorting to asexual reproduction when pollinators are scarce. Summary Mycoheterotrophy is an adaptation that allows survival in environments with low irradiance and minimal competition from autotrophic plants. However, such environments can negatively impact bee pollination, as most bees prefer open habitats. Despite this, the mycoheterotrophic orchid Gastrodia elata is known to rely on Lasioglossum bees for pollination. We investigated the reproductive biology of G. elata to understand how it overcomes pollinator limitation. Our research focused on the chemical composition and anatomical basis of G. elata pseudopollen (a substance that mimics pollen and may facilitate pollination), based on micromorphological and nutritional analyses, as well as observations of pollinator behavior. Additionally, we explored the potential presence of autogamy or agamospermy as mechanisms for reproductive assurance. The pseudopollen in G. elata originates from the disintegration of the adaxial parenchymatous tissue of the callus and is rich in starch. This contrasts with pseudopollen in most orchids, which typically originates from lip hairs and whose potential attractant is protein. Lasioglossum bees pollinating G. elata visit multiple flowers and actively collect pseudopollen. Furthermore, agamospermy serves as a reproductive safeguard in shaded habitats where insect‐mediated pollination is infrequent, at least in the investigated population. Our findings suggest that Gastrodia elata pseudopollen plays an important role in enhancing insect‐mediated pollination, particularly in relatively open habitats, while agamospermy ensures fruit set in shaded environments of the investigated population. Both pseudopollen production and agamospermy likely help overcome the pollination constraints posed by the mycoheterotrophic lifestyle.

Insects have a complex coevolutionary history with bacterial symbionts, among which Wolbachia pipientis stands out for its prevalence and role in reproductive manipulation. Wolbachia can induce cytoplasmic incompatibility, feminisation, male killing, and parthenogenesis, greatly influence the population genetics of their hosts and are potential drivers of invertebrate speciation. We might then assume that Wolbachia could act synergistically with other factors, such as niche conservation and isolation by distance, to drive speciation in hyper-diverse invertebrate taxa. The Fijian archipelago hosts a remarkable and recently diverged clade of Lasioglossum (Homalictus) bees. Some of these Lasioglossum have highly unusual species-level sex ratios and mitochondrial diversities, which can be hallmarks of infection by a bacterial reproductive manipulator. To examine the role of Wolbachia in Fijian Lasioglossum speciation, we screened the endemic Fijian bees for Wolbachia using the Wolbachia surface protein gene (wsp). We compare the distribution of Wolbachia infection across species with host mitochondrial haplotype diversity and conducted phylogenetic analyses to determine the relationship of host relatedness and symbiont infection status. We found that Wolbachia haplotypes probably span across supergroups A and B. In addition, we found multiple haplotypes were highly similar, with the most abundant group of wsp haplotypes being closely related with the drosophila Wolbachia strain wHa. We found evidence of mostly horizontal and limited vertical transmission, and little evidence for Wolbachia-host cospeciation. We show that, contrary to general patterns, Wolbachia-infected Lasioglossum species have higher mitochondrial diversity. Finally, we present evidence for the potential of multiple modes of host manipulation in this clade. [ABSTRACT FROM AUTHOR]

Context: Australia has numerous threatened species of terrestrial orchid, with a particularly high incidence of rarity in the genus Prasophyllum R.Br. Although there has been research on mycorrhizal associations and propagation, little is known about the reproductive ecology of threatened Prasophyllum. Understanding which animals are responsible for pollination and the impact of herbivores on reproduction may inform conservation actions. Aims: For the nationally Critically Endangered Prasophyllum innubum , we aimed to determine the pollinator species, test for self-pollination, quantify levels of reproductive success and herbivory, and identify herbivores. Methods: Pollinator observations were undertaken at wild populations of P. innubum , whereas an experiment testing for self-pollination was undertaken in shadehouse conditions. We quantified reproductive success and herbivory at two populations and attempted to identify herbivores using game cameras. Key results: Pollination occurred via three species of bee and a sphecid wasp, all of which attempted feeding on floral nectar. Fruit set averaged 72–84% at wild sites, whereas only 6% of flowers set fruit via self-pollination when insects were excluded. Just 4% of inflorescences were completely consumed by herbivores, and no herbivory was captured on camera. Conclusions: P. innubum has a generalist rewarding pollination system that confers high levels of reproductive success, with herbivory having little impact on reproduction. Implications: Pollinator availability is unlikely to restrict conservation translocation site selection of P. innubum because of a generalist pollination system. If herbivores are a threat for this species, it is likely to be through alteration of habitat rather than direct grazing. For the Critically Endangered Prasophyllum innubum , pollination occurs via three species of bee and a sphecid wasp, suggesting a generalised strategy that may offer flexibility when selecting sites for conservation translocation. Fruit set averaged 72–84%, despite a minimal contribution from self-pollination. Only 4% of inflorescences were consumed by herbivores, meaning that if herbivores are a threat for this species, it is likely to be through alteration of habitat rather than direct grazing. Photograph by Tobias Hayashi. [ABSTRACT FROM AUTHOR]

Large parts of the Pacific were thought to host low bee diversity. In Fiji alone, our recent estimates of native bee diversity have rapidly increased by a factor of five (from 4 to >22). Here, we show how including sampling of the forest canopy has quickly uncovered a new radiation of Hylaeus (Hymenoptera: Colletidae) bees in Fiji. We also show that Hylaeus are more common across the Pacific than previously thought and solve one of Charles Michener's mysteries by linking the previously enigmatic French Polynesian Hylaeus tuamotuensis to relatives in Fiji. We use systematic techniques to describe eight new Hylaeus species in Fiji (n = 6), French Polynesia (n = 1), and Micronesia (n = 1), and discuss impressive dispersal events by this genus. These clades also double the number of Hylaeus dispersals out of Australia from two to four. Our discovery highlights the severe impact of bee sampling methods on ecological interpretations and species discovery, specifically that canopy sampling is needed to correctly assess forest bee diversity even where there is a very long record of sampling. It further highlights the potential for forests to host higher-than-anticipated diversity and conservation value. This has broad methodological and regulatory impacts for land managers seeking to make choices about pollination services and diversity. The new species are Hylaeus (Euprosopoides) chuukensis Dorey, Davies, and Parslow; H. (Prosopisteron) albaeus Dorey, Davies, and Parslow; H. (P.) apertus Dorey, Davies, and Parslow; H. (P.) aureaviridis Dorey, Magnacca, and Parslow; H. (P.) breviflavus Magnacca; H. (P.) derectus Dorey, Davies, and Parslow; H. (P.) navai Dorey, Davies, and Parslow; and H. (P.) veli Dorey, Davies, and Parslow. [ABSTRACT FROM AUTHOR]

Large parts of the Pacific were thought to host low bee diversity. In Fiji alone, our recent estimates of native bee diversity have rapidly increased by a factor of five (from 4 to >22). Here, we show how including sampling of the forest canopy has quickly uncovered a new radiation of Hylaeus (Hymenoptera: Colletidae) bees in Fiji. We also show that Hylaeus are more common across the Pacific than previously thought and solve one of Charles Michener’s mysteries by linking the previously enigmatic French Polynesian Hylaeus tuamotuensis to relatives in Fiji. We use systematic techniques to describe eight new Hylaeus species in Fiji (n = 6), French Polynesia (n = 1), and Micronesia (n = 1), and discuss impressive dispersal events by this genus. These clades also double the number of Hylaeus dispersals out of Australia from two to four. Our discovery highlights the severe impact of bee sampling methods on ecological interpretations and species discovery, specifically that canopy sampling is needed to correctly assess forest bee diversity even where there is a very long record of sampling. It further highlights the potential for forests to host higher-than-anticipated diversity and conservation value. This has broad methodological and regulatory impacts for land managers seeking to make choices about pollination services and diversity. The new species are Hylaeus (Euprosopoides) chuukensis Dorey, Davies, and Parslow; H. (Prosopisteron) albaeus Dorey, Davies, and Parslow; H. (P.) apertus Dorey, Davies, and Parslow; H. (P.) aureaviridis Dorey, Magnacca, and Parslow; H. (P.) breviflavus Magnacca; H. (P.) derectus Dorey, Davies, and Parslow; H. (P.) navai Dorey, Davies, and Parslow; and H. (P.) veli Dorey, Davies, and Parslow.

Simple Summary: Wild, ground-nesting bees are important pollinators of apple. They generally do not fly more than a couple of hundred meters from their nest, yet little is known of their preferred nest locations in apple orchards. This project set out to identify where ground-nesting bees are found in apple orchards, which species are present and what influences where they nest. Most of the bee nests were found in the bare ground underneath the apple trees. This area is normally maintained weed-free using a herbicide or mechanical weeding. In addition, fourteen species of ground-nesting bee were identified in the orchards. Hence, maintaining areas of bare ground in apple orchards during peak nesting times could improve nesting opportunities for ground-nesting bees and potentially improve pollination. Wild ground-nesting bees are key pollinators of apple (Malus domestica). We explored, (1) where they choose to nest, (2) what influences site selection and (3) species richness in orchards. Twenty-three orchards were studied over three years; twelve were treated with additional herbicide to increase bare ground with the remainder as untreated controls. Vegetation cover, soil type, soil compaction, nest number and location, and species were recorded. Fourteen species of ground-nesting solitary/eusocial bee were identified. Most nests were in areas free of vegetation and areas treated with additional herbicide were utilised by ground nesting bees within three years of application. Nests were also evenly distributed along the vegetation-free strips underneath the apple trees. This area was an important ground-nesting bee habitat with mean numbers of nests at peak nest activity of 873 per ha (range 44–5705), and 1153 per ha (range 0–4082) in 2018 and 2019, respectively. Increasing and maintaining areas of bare ground in apple orchards during peak nesting events could improve nesting opportunities for some species of ground-nesting bee and, combined with flowers strips, be part of a more sustainable pollinator management approach. The area under the tree row is an important contributor to the ground-nesting bee habitat and should be kept bare during peak nesting. [ABSTRACT FROM AUTHOR]

Many ground-nesting bees are known contributors to crop pollination, but only a few specialist pollinating species are managed within agricultural systems. On the whole, most species (including the very large genus Lasioglossum) have been ignored for their crop pollination contribution, largely because of their perceived inability to be effective pollinators. Lasioglossum species are globally very widespread, including across many different environmental and ecological niches. Scattered reports provide credible evidence that these commonly small bees are effective pollinators across a wide range of crops, particularly as they often nest in close aggregations and may be present in crops in large numbers. Given the frequency and flexibility of this genus as flower visitors of many crops, further research to assess their effectiveness as pollinators deserves much greater focus. This is starting to change as assessments begin highlighting their effectiveness as pollinators of a range of crops. Preliminary attention is now being placed on developing potential management (or at least population-influencing) practices to enhance their use. [ABSTRACT FROM AUTHOR]

The halictid genus Lasioglossum, as one of the most species‐rich bee groups with persistently contentious subgeneric boundaries, is one of the most challenging bee groups from a systematic standpoint. An enduring question is the relationship of Lasioglossum and Homalictus, whether all halictine bees with weakened distal wing venation comprise one or multiple genera. Here, we analyzed the phylogenetic relationships among the subgroups within Lasioglossum s.l. based on thousands of single‐copy orthologs and ultraconserved elements, which were extracted from 23 newly sequenced low‐coverage whole genomes alongside a published genome (22 ingroups plus 2 outgroups). Both marker sets provided consistent results across maximum likelihood and coalescent‐based species tree approaches. The phylogenetic and topology test results show that the Lasioglossum and Hemihalictus series are reciprocally monophyletic and Homalictus and Rostrohalictus are valid subgenera of Lasioglossum. Consequently, we lower Homalictus to subgenus status within Lasioglossum again, and we also raise Rostrohalictus to subgenus status from its prior synonymy with subgenus Hemihalictus. Lasioglossum przewalskyi is also transferred to the subgenus Hemihalictus. Ultimately, we redefine Lasioglossum to include all halictine bees with weakened distal wing venation. [ABSTRACT FROM AUTHOR]

Pollination and pest control are two major ecological functions sustaining crop yield. In insect‐pollinated crops, previous studies have revealed that an increase in resources and habitats in landscapes can increase pest control by natural enemies as well as insect pollination by pollinators. However, data have been lacking that simultaneously considers the effects of landscape on both pollinators and pests, and the direct and indirect effects on yields of farming practices interacting with landscape, bees and pests.This study aimed to fill this gap by focusing on oilseed rape (OSR), an insect‐pollinated crop of high economic value. We first quantified the effects of landscape and farming practices on both bee and pest abundance caught in OSR blooming season in 124 farmed fields over a 6‐year study (~20 fields sampled per year), and then used structural equation modelling to assess the direct and indirect links between bees, pests, farming practices and landscape on yield.The results showed that landscape had a stronger effect on bee and pest abundance than agrochemical farming practices. Bees and pests decreased with the amount of OSR in the landscape surrounding the focal field, and showed contrasted effects with the amount of meadow and organic farming: positive for bees and negative for pests. Bee abundance also increased with the amount of sunflower in the landscape the preceding year, and decreased with increasing field size.While agrochemicals surprisingly had barely any effect on bees and pests, their use improved OSR yield, although at a similar magnitude as bee and pest abundances.Synthesis and application. This study, conducted in commercial crop fields, underlines the important contribution of sustainable landscape management for enhancing OSR yield. Despite agrochemicals' ability to improve or maintain OSR yields, their unconditional use is unsustainable due to negative externalities. Therefore, alternative options such as those highlighted in our study—such as reducing field size, increasing the amount of organic farming in the landscape, or sowing OSR in landscapes rich in sunflowers the preceding year—appear to be relevant tools to promote ecosystem services, maintain yield and conserve biodiversity. These findings support the potential of nature‐based solutions to foster more sustainable agriculture. [ABSTRACT FROM AUTHOR]

The sweat bees from Fernando de Noronha Archipelago are presented and illustrated herein. The species recorded are Augochlora (Augochlora) laevipyga (Kirby, 1890), Augochlora (Augochlora) sp., new record, and Lasioglossum (Dialictus) atripyga (Kirby, 1890). The Kirby species are redescribed based on recently collected specimens, including the first illustration of the male terminalia. The unidentified species is also shortly characterized. [ABSTRACT FROM AUTHOR]

Sicily (Italy) is an important hotspot diversity for bees and new species records are constantly reported for the island. Here, we rediscovered after 45 years without records, the occurrence in Eastern Sicily of Lasioglossum marginatum (Brullé 1832) confirmed by DNA barcoding. This is the only known species of eusocial sweat bees (Halictidae) with perennial colonies. Since a single female was collected in our large 2-years bee sampling, combined with its absence in previous collections, this species is suggested to be rare in Sicily. [ABSTRACT FROM AUTHOR]

Agroecosystems are often impoverished ecosystems, but they can host diverse communities of insects which provide ecosystem services. Specifically, crops may benefit from insect pollinators that increase their quantity and quality of yields. Basic knowledge is still needed regarding the identity, diversity, abundance, and ecology of insect pollinators in many parts of the world, especially in low and middle-income countries. In this study we investigate the potential of agroecosystems and crops in Morocco to host a high diversity of insect pollinators. We sampled insects in four eco-climatic regions encompassing a total of 22 crops for 2 years (2018–2019). After describing the general pattern of diversity and abundance of insect pollinators, we focused our comparative analyses on bees as they are known to be the most efficient and abundant group of insect pollinators. We recorded a total of 53,361 insect pollinators in all agroecosystems among which 37,091 were visiting crop flowers. Bees were by far the most abundant group visiting crops. Honeybees represented 49% of crop visitors followed by wild bees representing 33% of relative abundance. Three genera (Lasioglossum, Andrena, and Xylocopa) represented 53% of the total abundance of wild bees visiting crops. We identified a total of 213 species visiting crops (22% of national wild bee species richness). A comparison of the abundance, species richness, and community composition of wild bees visiting the same crops showed significant inter-regional differences for zucchini, faba bean, and eggplant. This study highlights the high diversity of pollinators in Moroccan agroecosystems and represents an important step toward exploring the Moroccan pollinator fauna. It provides basic information for future studies on pollinator conservation and pollination services.

Wild ground-nesting bees are key pollinators of apple (Malus domestica). We explored, (1) where they choose to nest, (2) what influences site selection and (3) species richness in orchards. Twenty-three orchards were studied over three years; twelve were treated with additional herbicide to increase bare ground with the remainder as untreated controls. Vegetation cover, soil type, soil compaction, nest number and location, and species were recorded. Fourteen species of ground-nesting solitary/eusocial bee were identified. Most nests were in areas free of vegetation and areas treated with additional herbicide were utilised by ground nesting bees within three years of application. Nests were also evenly distributed along the vegetation-free strips underneath the apple trees. This area was an important ground-nesting bee habitat with mean numbers of nests at peak nest activity of 873 per ha (range 44–5705), and 1153 per ha (range 0–4082) in 2018 and 2019, respectively. Increasing and maintaining areas of bare ground in apple orchards during peak nesting events could improve nesting opportunities for some species of ground-nesting bee and, combined with flowers strips, be part of a more sustainable pollinator management approach. The area under the tree row is an important contributor to the ground-nesting bee habitat and should be kept bare during peak nesting.

Female and male bees forage for different reasons: females provision nests with pollen appropriate for larval development and consume nectar for energy while males need only fuel their own energetic requirements. The expectation, therefore, is that females should visit fewer floral resource species than males, due to females' focus on host plant species and their tie to the nest location. We used pollen collected from bees' bodies and the flowers they were collected on to infer floral resource use in 2010–2012 at Badlands National Park, SD, USA. We collected bees on 24 1-ha plots centered on particular plant species. We compared number of floral species and families (1) associated with individual female and male bees (via generalized linear mixed models) and (2) accumulated by each sex (using rarefaction); and (3) effect of variation between sexes in plant-bee interactions via modularity analyses. Analyses were restricted to bee species with ≥ 5 individuals per sex. Contrary to expectation, female and male bees differed infrequently in the number of floral resources they had visited, both on single foraging bouts and collectively when accumulated across all males and females of a species. When males and females did differ, males visited fewer floral species than females. Generalist and specialist bee species did not differ markedly in floral resource use by females and males. When separated by sex, seven of eleven species occupied different modules than they did when analyzed as a species; most of the bee species were connectors, thus important for stability of the network during perturbations. [ABSTRACT FROM AUTHOR]

We investigated the diversity and behaviors of insects that visit flowers of four native species and a horticultural hybrid species of genus Melastoma (Family Melastomataceae) at the Fushan Botanical Garden in Taiwan biweekly from May to August 2020. Behaviors of flower-visiting insects were classified into eight categories and further assigned into four insect-flower interactions, namely pollination, herbivory, commensalism, and neutral. Our project provides baseline data of pollinator-plant interactions between the endangered M. intermedia and sympatric Melastoma species. Such information is useful in generating conservation and management actions as interspecific hybridization and genetic introgression has been reported from both wild and cultivated populations in this genus.A total of 1,289 visits to flowers were recorded by at least 63 insect species belonging to seven orders. Number of insect species recorded per Melastoma species ranged from 9 to 39. Visiting, sonication, and passing were the three most frequently recorded behaviors, collectively accounting for 90.2% (n = 1,240) of the total observations. Pollination was the most dominant insect-flower interaction, accounting for 70.2% of the total observations, followed by neutral interaction (20.0%), herbivory (6.3%), and commensalism (3.5%). Sweat bees of genera Lasioglossum and Maculonomia (Hymenoptera: Family Halictidae) are considered key pollinators to Melastoma species in Fushan Botanical Garden based on their high number of visits and sonication behaviors. Our study represents the first comprehensive checklist of insects that visit the flowers of Melastoma species in Taiwan.

Olive groves constitute a landscape that covers a large area in the Mediterranean basin, with essential economic importance, but which can also have environmental importance if an olive grove landscape is designed that favours populations of beneficial insects. Bees are also essential from an economic and environmental viewpoint and are in increasing decline. This work aimed to determine the landscape parameters in the olive agroecosystem that favour bee populations. Fifteen olive groves were sampled in central Spain throughout 2015 and 2016. Bees belonging to 6 families and 24 genera were captured. The most numerous family was Halictidae, and the most numerous genus Lasioglossum. The parameter that mostly affected the abundance and richness of bee genera was the scrubland area (CAMME), with a positive effect. The olive grove area (CAO) had a negative effect in general, although the responses of the different families vary slightly. The configuration of the landscape (MSI) also positively affected bees, which indicates the importance of maintaining linear elements with wild vegetation, to contribute to the maintenance of these important insects. Environmental conditions can affect the importance of olive grove as a supplier of resources for bees, being greater in dry and warm years. [ABSTRACT FROM AUTHOR]

A revised key to the 94 species of Lasioglossum (Dialictus) currently known to occur in Canada is presented, incorporating new species and taxonomic updates since the publication of the first key in 2010. Two new species, Lasioglossum (Dialictus) immigrans and Lasioglossum (Dialictus) onuferkoi, are described from Canada. Lasioglossum (D.) ascheri, L. (D.) stictaspis, and L. (D.) tegulariforme are reported or confirmed from Canada for the first time. Lasioglossum (D.) gaudiale (Sandhouse, 1924) and L. (D.) helianthi (Cockerell, 1916) are resurrected from synonymy with L. (D.) tegulariforme (Crawford, 1907). The following five new synonymies are established: L. (D.) stictaspis (Sandhouse, 1923) (= L. (D.) albuquerquense (Michener, 1937)); L. (D.) ascheri Gibbs, 2011 (= L. (D.) curculum Gibbs, 2011); L. (D.) helianthi (Cockerell, 1916) (= L. (D.) imbrex Gibbs, 2010); L. (D.) megastictum (Cockerell, 1937) (= L. (D.) punctiferellum (Cockerell, 1937)); and L. (D.) obnubilum (Sandhouse, 1924) (= L. (D.) lilliputense Gibbs, 2010). Previously undescribed males of L. (D.) helianthi, L. (D.) reasbeckae, L. (D.) tegulariforme, and L. (D.) weemsi are diagnosed and figured. [ABSTRACT FROM AUTHOR]

The Australian Lasioglossum Curtis 1833 subgenus Australictus Michener 1965 is revised. Of the 11 available names listed by Michener (1965) for the subgenus Australictus, six are placed in synonymy. A species placed by Michener (1965) in the Lasioglossum subgenus Parasphecodes Smith 1853 is recombined to the subgenus Australictus, and four other species, placed in Parasphecodes by Michener (1965), are synonymised with this valid, recombined taxon, and the species name of the taxon is reverted to its original spelling. In addition, a species placed in Australictus by Michener (1965) is synonymised with a valid species in the Lasioglossum subgenus Chilalictus Michener 1965. These changes provide five valid names for the subgenus Australictus. New synonymies, recombined names and valid species proposed for Lasioglossum (Australictus) are as follows: New synonymies - Lasioglossum (Australictus) kurandense (Cockerell 1914) syn. nov., Lasioglossum (Australictus) nigroscopaceum (Friese 1917) syn. by Cockerell 1929 but listed by Michener (1965: 165) as valid = Lasioglossum (Australictus) davide (Cockerell 1910a); Lasioglossum (Australictus) insculptum (Cockerell 1918) syn. nov., Lasioglossum (Australictus) rufitarsum (Rayment 1929) syn. nov. and Lasioglossum (Australictus) fulvofasciae Michener 1965 syn. nov. = Lasioglossum (Australictus) tertium (Dalla Torre 1896); Lasioglossum (Australictus) franki (Friese 1924) syn. nov. = Lasioglossum (Chilalictus) orbatum (Smith 1853). New combination and new synonymies - Lasioglossum (Parasphecodes) lithuscum (Smith 1853) comb. nov. moved to Lasioglossum (Australictus) lithusca; Lasioglossum (Parasphecodes) adelaidae (Cockerell 1905) syn. nov., Lasioglossum (Parasphecodes) griseipenne (Cockerell 1929) syn. nov., Lasioglossum (Parasphecodes) stuchilum (Smith 1853) syn. nov., Lasioglossum (Parasphecodes) wellingstoni (Cockerell 1914) syn. nov. = Lasioglossum (Australictus) lithusca. Valid is Lasioglossum (Australictus) plorator (Cockerell 1910b). New female subgeneric mandibular characters are added to Michener's (1965) diagnostics for Australictus - mandible with elongated and enlarged preapical tooth, reduction in width of basal tooth at apical end and in dorsal view, broadening of width at base of mandible. The mandibular modifications, widening of the head basally and enlarged gena are associated with Australictus behaviour to nest in wood rather than ground nesting in soil as is usual for Halictidae bees. The shape of the female mandible, especially in dorsal view, resembles a wood-splitting axe - hence the common name coined here, "Wood-Splitting Axe Bees". Australictus is the first record of wood-nesting bees for Australian Halictidae. All valid species are redescribed; keys to both sexes, montage diagnostic images and distribution maps are provided to assist with species identification. [ABSTRACT FROM AUTHOR]

Cypripedium genus is represented by 59 species and nothospecies (species of hybrid origin), mainly distributed across North, Central and South America, Europe and Asia, but absent from Madagascar and Australia. The most important characteristic of this genus is their showy and large labellum, which transformed into the specific slipper-shaped, vividly coloured, inflated pouch. In Romania, the genus is represented by one species only, Cypripedium calceolus. The article contains the first description of a newly discovered population in Prahova County, as well as a complete illustration of a Cypripedium calceolus flower pollinated by a female bee of the Lasioglossum genus. The flowers are passive traps pollinated by bees of particular type and size. The article describes in detail different mimicry (deceit) pollination strategies employed by the orchid in order to exploit its insect pollinators (generalized food deception mimicry, shelter mimicry, nest/brood-site mimicry, rendezvous attraction). Using advanced techniques of ultra-macro photography, details of floral organs are illustrated in order to describe in great detail the intriguing deceptive pollination mechanisms and mimicry strategies employed by the Slipper Orchids to attract their highly specific and rather scarce pollinating insects. Along with the detailed description and illustration of the common single-flowered plants, we also describe rare Cypripedium calceolus f. biflorum plants in Prahova County and present for the first time in Romania, a unique Cypripedium calceolus var. citrina individual, found in 2019, in Suceava County. [ABSTRACT FROM AUTHOR]

I propose a redefinition of the sexstrigatus group of Lasioglossum (Hemihalictus) Cockerell, 1897, including a phylogenetic analysis. This group is characterised by a combination of the following 12 characteristics: male antenna short, not attaining to metasoma, male labrum with distal process and well-developed basal elevation, male head with genal process as variation, female mesepisternum reticulate-punctate on lower area, mesepisternum without tubercle in both sexes, female metasomal terga with distinct fimbriae on posterior margin, male S8 with well-developed median process, gonobase ventral arm of male genitalia connected with each other at upper ends, gonocoxite of male genitalia smooth, gonostylus of male genitalia small and simple, bud-like, and the ventral retrorse lobe of male genitalia not attaining to gonobase. The Japanese species of the sexstrigatus group are revised. Thirteen species in total are recognised, including three new species: Lasioglossum (Hemihalictus) ikudomei sp. nov., L. (H.) spectrum sp. nov., and L. (H.) subsimplicior sp. nov. Lasioglossum (Hemihalictus) perplexans (Cockerell, 1925) is synonymised under L. (H.) kiautschouense (Strand, 1910). A key to the Japanese species is provided. Bionomical data, such as flight and flower records or habitat, are reported for some species. The distributions of all species are mapped. DNA sequences including a part of the barcode region are given for L. (H.) kiautschouense, L. (H.) ohei Hirashima & Sakagami, 1966, L. (H.) speculinum (Cockerell, 1925), L. (H. ) spectrum sp. nov., L. (H. ) subsimplicior sp. nov., and L. (H. ) taeniolellum (Vachal, 1903).

Colour signalling by flowers appears to be the main plant-pollinator communication system observed across many diverse species and locations worldwide. Bees are considered one of the most important insect pollinators; however, native non-eusocial bees are often understudied compared to managed eusocial species, such as honeybees and bumblebees. Here, we tested two species of native Australian non-eusocial halictid bees on their colour preferences for seven different broadband colours with bee-colour-space dominant wavelengths ranging from 385 to 560 nm and a neutral grey control. Lasioglossum (Chilalictus) lanarium demonstrated preferences for a UV-absorbing white (455 nm) and a yellow (560 nm) stimulus. Lasioglossum (Parasphecodes) sp. showed no colour preferences. Subsequent analyses showed that green contrast and spectral purity had a significant positive relationship with the number of visits by L. lanarium to stimuli. Colour preferences were consistent with other bee species and may be phylogenetically conserved and linked to how trichromatic bees processes visual information, although the relative dearth of empirical evidence on different bee species currently makes it difficult to dissect mechanisms. Past studies and our current results suggest that both innate and environmental factors might both be at play in mediating bee colour preferences. [ABSTRACT FROM AUTHOR]

Brood parasites need to overcome host detection in order to exploit their target resource. Nest invasion by brood parasites is possibly enabled either by chemical mimicry (innate odour match with host), camouflage (acquired odour match with host) and/or chemical insignificance (odour reduction). We analysed which of these strategies may be used by the cuckoo bees Sphecodes monilicornis and S. puncticeps to sneak into the nests of their social Lasioglossum bee hosts. In staged dyadic encounters, the host bee workers interacted much more rarely towards S. monilicornis than towards nestmates, suggesting that the host bee may weakly detect this cuckoo bee in the nest. Cuticular hydrocarbon (CHC) profiles of S. monilicornis included about 30–50% of compounds found on host bees, possessed exclusively linear alkanes, a class known to be generally less important in nestmate recognition, and lacked exclusive compounds. S. monilicornis may thus avoid recognition by hosts through chemical insignificance. On the other hand, S. puncticeps has a more complex CHC profile including several exclusive methyl-branched alkanes, though no alkenes. This cuckoo bee species does not seem to use either chemical mimicry or insignificance to invade host nests. However, only a large comparative study may elucidate the evolution of CHC adaptations in Sphecodes to their hosts' template. [ABSTRACT FROM AUTHOR]

Aculeata pollinators of Adonis vernalis were collected in the spring of 2018 and 2019 to compare the species composition and number of pollinators in different years. 364 individuals were encountered in 2018 and only two of them were males. In 2019, 717 individuals were captured out of which four were males. The number of collected individuals in the same amount of time was significantly different in the two years. In 2019, we collected nearly twice as much pollinators than in 2018. Nine species were observed in 2018 only, nine in 2019 only, while 13 species were collected in both years. Species occurring in both years accounted for most of the dominance, thus the pollinating community can be considered stable. Lasioglossum xanthopus was dominant among the Aculeata pollinators of A. vernalis in both years, while L. marginatum had a subdominant role. The Lasioglossum and Andrena genera were the most species-rich in both years. In 2018, the Osmia and Nomada genera were the least species rich, while for 2019 these were the Ludita and Polistes genera. The daily rhythm of flight of pollinators was different in the two study years as well. In 2018, the pollinators were most active in the period between 12 and 2 p.m., while in 2019 we collected the most pollinators between 11 a.m. and noon. In 2018, the number of collected individuals per hour fluctuated, but in 2019 it continuously increased until 10-11 a.m., and then monotonously decreased. Our results confirm the influence of different years on the species composition, species number and daily rhythm of flight for A. vernalis pollinators. In spite of the often-mentioned recent pollination crisis, we collected a considerable number of pollinators in both years. Conservation management of the studied area and the protection of pollinators are very important to maintain the wellfunctioning plant-pollinator systems in A. vernalis populations. [ABSTRACT FROM AUTHOR]