Bee Species Research Articles

Karyotypes and chromosomal mapping of some repetitive DNAs in two stingless bee species (Apidae: Meliponini), with the description of a B chromosome in Plebeia genus.

Cytogenetic studies on stingless bees have significantly contributed to our understanding of karyotypic evolution and the composition of euchromatin and heterochromatin regions, including repetitive sequences. In this study, we performed classical cytogenetics, chromosomal banding, and mapping of some repetitive sequences in two stingless bee species, Frieseomelitta trichocerata and Plebeia poecilochroa. The species exhibit the typical diploid chromosome number of each genera, 2n=30 for Frieseomelitta and 2n=34 for Plebeia. Additionally, some individuals of P. poecilochroa presented a small heterochromatic B chromosome, showing a numeric variation of n=17 to 18 in males and 2n=34 to 35 in females. In both species heterochromatin is primarily distributed in the short arm and centromeric regions. Centromeric regions were found to be AT-rich in both species, while subterminal/terminal regions of the short arms of one and six chromosomes presented GC-rich sites in P. poecilochroa and F. trichocerata, respectively. The rDNA clusters mapped on two chromosome pairs in F. trichocerata, and in only one in P. poecilochroa. Microsatellites (GA)n, (GAG)n, and (CAA)n were predominantly mapped in euchromatic regions, while the telomeric motif (TTAGG)n mapped to the ends of most chromosomes, including the B chromosome of P. poecilochroa. The other repetitive probes used, including the rDNA clusters, do not label the B chromosome of P. poecilochroa. Our cytogenetic data highlight both similarities and differences when compared to other congeneric species, expanding the chromosomal data for both genera.

Corymbia calophylla (Marri) (K. D. Hill & L. A. S. Johnson) (Myrtaceae) is a major resource for native bees in the southwest western Australian biodiversity hotspot

Context A theoretical paradigm proposes that certain species can serve as ‘keystone species’ or ‘magnets’, being particularly important for biodiversity. Aims We present evidence that in the context of supporting Indigenous native bees, this is indeed the case for the tree Corymbia calophylla (Marri), a Myrtaceae endemic to southwest Western Australia. Methods To assess the role of C. calophylla as a resource for native bees, we collated the number of species recorded from surveys across 16 sites, and specimens lodged in the WA Museum. Its capacity to support wild bees was assessed from abundance of bees visiting this species (total and relative to other plants visited) from 24 sites. Key results Corymbia calophylla was visited by 81 species of native bees, and is often the main, or only, plant species visited. It blooms at a crucial time when most species have finished flowering at the end of summer. Conclusions We argue that C. calophylla represents a crucial landscape resource for native bees. Implications Protection and management of C. calophylla is likely to be important for preservation of native bee biodiversity.

ANTIOXIDANT ACTIVITIES AND PHYTOCHEMICAL COMPOUND OF STINGLESS BEE HONEY (Heterotrigona itama) COLLECTED FROM Calliandra calothyrsus PLANTATION IN EAST KALIMANTAN, INDONESIA

Stingless bee honey is one of the most valuable insect products. The increasing popularity of stingless bee honey can be attributed to its composition, which has been linked to medicinal properties. Beekeeping with stingless bees is well-known in Indonesia, with Heterotrigona itama is the most popular stingless bee species cultivated in East Kalimantan, Indonesia. Stingless bees utilize various plant species as sustenance sources. Among those plants, Calliandra calothyrsus is popular planting in Indonesian bee plantations. This study analyzed the antioxidant (DPPH assay), phytochemical (qualitative method), water, and sugar content of H. itama stingless bee honey collected from a C. calothyrsus plantation. The results show that the water and sugar contents of the honey in this study were higher than in other research. Meanwhile, antioxidant capacity was also higher than in other studies. The phytochemical contents detected from honey in this study were carotenoids, coumarins, flavonoids, saponins, steroids, tannins, and triterpenoids. Even though the properties of stingless bee honey can differ based on vegetation and geographical origin, H. itama stingless bee honey collected from C. calothyrsus plantation in East Kalimantan, Indonesia, showed potential antioxidant activity and phytochemical content, which is advantageous to human health.

Spatiotemporal variability and foraging behavior of bee visitors to a rare long-lived iteroparous forb, Silene spaldingii (Caryophyllaceae).

Silene spaldingii S Watson is a rare long-lived forb (Caryophyllaceae) found primarily in open native grasslands of the Inland Pacific Northwest and is putatively pollinated by one key bumble bee pollinator, Bombus fervidus (Fabricius). However, populations of bumble bees and their visitation patterns can vary dramatically, and some species are in decline including B. fervidus. Understanding the role of co-pollinators such as sweat bees (Halictidae) could be crucial as the plight of rare plants and pollinators intensifies. We collected data across three seasons (2015-2017) on the Bombus-S. spaldingii pollination system, focusing on three Key Conservation Areas in the Channeled Scablands of eastern Washington. Bee visitors to S. spaldingii were monitored and the pool-of-pollinators was surveyed with blue vane traps. Nine species of bees were observed foraging on the plant, while 2211 bees comprised of five families, 22 genera and 81 taxa were captured in blue vane traps, meaning only 11.1% of species in the pollinator pool visited S. spaldingii. Halictus tripartitus Cockerell, a sweat bee, was a common visitor to the plant, but this was the first record of visitation for several other species, including Lasioglossum buccale (Pérez) which has never before been recorded in the Americas. These sweat bees appear to vector S. spaldingii pollen, suggesting they are co-pollinators of the plant. Weather and patch characteristics affected visitation patterns and the pool-of-pollinators. We conclude that sweat bees are likely co-pollinators of S. spaldingii and that they could become increasingly important if B. fervidus populations continue to decline.

An update on the wild bee fauna (Hymenoptera, Apoidea, Anthophila) of Serbia

Numerous wild bee (Hymenoptera, Apoidea, Anthophila) species show negative population trends, while the knowledge gaps on their occurrences and distributions prevent adequate conservation actions. The need for continuous updating of species records and reconfirmation of their presence has been recognized, especially in understudied areas. The present study presents the results of bee monitoring at 30 Serbian localities, each surveyed three times during 2023. Two sampling methods were used, the transect walks and the pan traps, resulting in a detection of 232 wild bee species. Among them, 13 species found at 13 localities, represent the first published records from Serbia: Andrena ferox Smith, 1847, A. nana (Kirby, 1802), A. praecox (Scopoli, 1763), A. pusilla Pérez, 1903, A. susterai Alfken, 1914, A. angustior (Kirby,1802), A. curvungula Thomson,1870, A. falsifica Perkins, 1915, Hoplitis mitis (Nylander, 1852), Hylaeus friesei (Alfken, 1904), Melitta melanura (Nylander, 1852), Nomada trapeziformis Schmiedeknecht, 1882, and Osmia uncinata Gerstaecker, 1869. This study contributes to an update of the list of bee species in Serbia, that now counts 744 species, and also provides additional data on European distributions. The new information on Melitta melanura is especially noteworthy, since this species has been assessed as Endangered by the European Red List of Bees due to its small area of occupancy and a severely fragmented distribution. Other important findings include the confirmation of the presence of some wild bee species in Serbia, i.e., 10 species reported as new records within the previous update, and 19 species that were without previously available records from the 21st century. Additionally, the present study indicates the effectiveness of both conducted monitoring techniques, in terms of different recorded species and numbers of specimens. These results lead to the conclusion that corroborates the application of complementary sampling methods as an adequate way to survey bee diversity and abundance.

On Butterflies and the Carpenter Bees (Xylocopa caffra): Perceived Ecological Roles and Description of Traditional Children’s Games in Mayotte (French island, Indian Ocean of East Africa)

With over a million described species, insects are the most diverse group of animals on Earth. Insects, particularly those responsible for pollination, play a major ecological role that is often overlooked or even ignored. Indeed, apart from honeybees, many species are not recognized for the services they provide. What is more, all pollinating insects do not attract the same affection. Some, such as butterflies, enjoy a very positive image, while others are feared or hated, often because they can sting. During a semi-structured interview study (N = 35) on the island of Mayotte, we confirmed these views. On the other hand, butterflies and one species of carpenter bee were the subject of many children’s play and games, which have now been abandoned. Those who played with them in the past, and more simply enjoyed watching children play, seem to bitterly regret it.

Neither nectar nor deception: the role of floral rewards in the pollination system of Laelia (Orchidaceae: Laeliinae).

Orchids offer a variety of floral rewards to pollinators. In many orchid groups, however, the transfer of pollen is based on food-deception, as in the case of Laelia (including Schomburgkia s.s.), a genus assigned to the Neotropical subtribe Laeliinae. Here, we report on the reproductive biology of a Brazilian member of this subtribe, namely, Laelia gloriosa, occurring in the forested areas of southeastern Brazil. The study includes analyses of floral morphology, histochemistry, and the chemical analysis of floral rewards and scents. Pollinators and pollination mechanism data were collected in the field by means of focal observations. Analyses of breeding systems and the percentage of potentially viable seed were also recorded. The floral morphology of Laelia gloriosa indicates that this species is melittophilous. The flowers release a citrus-like fragrance that attracts many species of bee. The flowers offer waxy material as a reward, and this is collected exclusively by Meliponini bees. Several bee species visit the flowers. However, those of L. gloriosa are pollinated exclusively by Trigona spinipes. Pollinaria are deposited on the bee's scutellum. Plants of the studied population were entirely self-compatible, but pollinator-dependent. The frequency of visits to these flowers was greater than in rewardless Laeliinae. Our study provides the first evidence of lipoidal substances as a resource in Laeliinae. The discovery that an orchid species (Laelia gloriosa) of this subtribe, hitherto considered to be entirely pollinated by nectar-seeking pollinators, offers a floral waxy material and provides new insights into the evolution of this important subtribe.

A test method for assessing chronic oral toxicity of a pesticide to solitary nesting orchard bees, Osmia spp. (Hymenoptera: Megachilidae).

Orchard bees of the genus Osmia Panzerare important pollinators of fruit trees in various regions of the world, with some species commercially available in the United States and Europe. In addition to their pollination services, Osmia lignaria, Osmia cornifrons, Osmia bicornis, and Osmia cornuta have been identified as potential model species for solitary bees in pesticide risk assessment and have been used for the development of new methods to test acute lethal effects via contact and oral routes of exposure. Our goal was to expand the available methodology to characterize the toxicity of pesticides for these solitary bees through a chronic oral test for adult bees. Chronic oral toxicity of pesticides to orchard bees has been reported, but methods differ among research groups. In our study, O. lignaria, O. cornifrons, O. bicornis, and O. cornuta female bees had access to sucrose solution ad libitum in separate, species-specific 10-day tests. Mean body mass, mean daily consumption, and survival differed among the studied bee species. The dose-response test design was validated with dimethoate, a reference toxic compound, and chronic toxicity endpoints were estimated for the 4 Osmia species. The median lethal daily doses normalized by weight for O. lignaria, O. bicornis, O. cornuta, and O. cornifrons were within the same order of magnitude at 0.23, 0.26, 0.49, and 0.61 µg dimethoate/g bee/day, respectively. The methodology described here was aligned as much as possible with the available honey bee and bumble bee standard methods to facilitate the comparison of chronic toxicity profiles among bee species.

Best management practices for bee conservation in forest openings

AbstractNative bees are an ecologically diverse group of pollinators in global decline due at least in part to invasive species, pesticides, and habitat loss. Although guidelines exist for land managers to restore pollinator habitat, these “best management practices” (BMPs) include other pollinator taxa that may have different requirements than bees, do not give particular attention to rare bee species, or describe practices that are impractical for land managers. Using co‐production science, our team of land managers and researchers sampled bee communities in 100 wildlife openings on six National Forests (NF) within the Great Lakes Basin of the United States during 2017–2019. We found that bee communities responded to site factors and management practices, including prescribed fire, mechanical methods (e.g., felling, brushhogging, mowing), herbicides, and pollinator plantings. Bee abundance, diversity, and rarity were strongly related to soil properties, landscape context, and the plant community, including small‐statured woody species, which collectively informed our BMPs. For instance, mechanical treatments were most beneficial for openings with clayey or organic soils while prescribed fire was most effective in openings with well‐drained soils. Our BMPs highlight effects of treatment combinations, including negative effects on rare species when herbicides were combined with plantings and positive effects on abundance and rare species when prescribed fire was combined with mechanical treatments. Since our BMPs were generated in collaboration with land managers, they better conform to their needs and constraints, contributing to more effective native bee conservation.

Not all male bees posses thirteen antennal segments: New megachilid species from the Afro-Arabian and Afrotropical regions (Apoidea: Anthidiini: Pseudoanthidium) with deviant numbers of segments

Male bees (Apoidea) typically possess antennae with 13 articles, with only a few exceptions reported, none of which are from the Megachilidae family. In this study, we describe two new species of the megachilid tribe Anthidiini that display an unusual characteristic – their males have only 12 antennal segments. We attributed these species, Pseudoanthidium omanicum sp. nov. from the Arabian Peninsula, and P. ethiopicum sp. nov. from Ethiopia, to the subgenus Pseudoanthidium (Mesanthidiellum), previously known only from Sub-Saharan Africa. Notably, the male of a third species in this subgenus, P. (Mesanthidiellum) sakaniense (Cockerell, 1936) was also found to have only 12 antennal segments. Further investigation revealed that males with antennae with 12 articles are also present in the closely related subgenus Pseudoanthidium (Branthidium), suggesting that this phenomenon may be more widespread yet often overlooked. A broader review indicates that deviations from the typical 13 antennal articles are known in 10 genera of bees and account for less than 0.5% of all bee species. We conclude that this trait has evolved independently across different bee lineages. However, the specific function of a reduced number of antennal articles remains elusive. http://www.zoobank.org/urn:lsid:zoobank.org:pub:56B808FB-E4F2-46A9-9B54-850AF83263D0

A focus on the Chinese stingless bee honey (Hymenoptera, Apidae, Meliponini): Exploring physicochemical parameters for establishing quality standards

Stingless bee honey (SBH) is the most important product from stingless bee colonies with great economic value and health benefits. Nevertheless, there is little information on the physiochemical parameters of Chinese SBH, which also limits its utilization and quality control. In the period 2019–2023, we collected 89 Chinese SBH samples produced by five stingless bee species from four provinces in China. We performed comprehensive assessments of various SBH physicochemical indicators. These parameters include moisture, trehalulose, sucrose, fructose, glucose, total soluble solids, Baumé, ash, pH, electrical conductivity, 5-hydroxymethylfurfural, and free acidity. Our data revealed that the physicochemical parameters of Chinese SBH are consistent with earlier reported results from other countries. Notably, the Chinese SBH exhibited a relatively low level of 5-hydroxymethylfurfural (0–9.64 mg/kg), sucrose (0–0.43 g/100 g), and no diastase activity was detected. Chinese SBH was rich in trehalulose (4.26–37.65 g/100 g). After comparing these indexes with published data and with Australian/Malaysian samples, we proposed a new food standard for regulations of Chinese SBHs. These findings provide crucial insights into the Chinese SBH and contribute significantly to developing quality control and global standards for SBH.

Foraging bee species differentially prioritize quantity and quality of floral rewards.

Pollinator-plant interactions represent a core mutualism that underpins biodiversity in terrestrial ecosystems, and the loss of flowering plants is a major driver of pollinator declines. Bee attraction to flowers is mediated by both quantity of resources (the number of available flowers for exploration) and quality of resources (pollen nutritional value), but whether and how bees prioritize these factors is not well understood. Here, we leveraged a unique plant system to investigate the floral factors influencing bee foraging decisions. Recombinant inbred plant lines were generated by crossing the self-fertilizing Capsella rubella and the pollinator-dependent outcrosser C. grandiflora, to produce plants that varied across floral traits. Using enclosed arenas, we evaluated the foraging behavior of two solitary bee species, Osmia cornifrons and Megachile rotundata, to the isolated inflorescences from these lines. Visits from O. cornifrons were significantly positively correlated with the number of flowers, while M. rotundata visits were significantly positively associated with pollen nutrition, with a preference for plants with higher pollen protein-to-lipid content. Further experiments using artificial flowers confirmed that M. rotundata preferred flowers with higher protein:lipid ratios, while O. cornifrons visits were unaffected by nutrition. These studies demonstrate that, although both bee species collect pollen as their sole source of protein and lipids for themselves and/or their offspring, they differentially prioritize resource quantity (number of flowers) and quality (pollen nutritional content). These studies lay the groundwork for understanding how different foraging strategies evolved, and influence, plant-pollinator ecological networks.

EUROPEAN PAPER BEES, POLISTES DOMINULA AND POLISTES NIMPHA (CHRIST, 1791) (HYMENOPTERA: VESPIDAE) PATHOGENS PRESENCE AND INSECTICIDAL EFFECTS OF THESE PATHOGENS ON HONEY BEES ADULTS OF APIS MELLIFERA CAUCASIA (POLLMANN, 1889)

Honeybee (Apis mellifera) is an important element of biodiversity and terrestrial ecosystems. Any pathogenic infection in this beneficial insect can lead to major undesirable disasters. In this study, we investigated the pathogenic bacterial and fungal potential of Polistes dominula and Polistes nympha (European paper bees) wasps and the insecticidal effects of these pathogens on honeybees (Apis mellifera). For this purpose, bacteria and fungi were isolated from dead and diseased bees collected from Terme district of Samsun province in Turkey in May and June 2020In the study, diseased and dead Polistes dominula paper wasp adults were identified as Serratia marcescens (no. 1), Enterococcus faecalis (no.6), Staphylococcus xylosus (no.9), Sphingomonas paucimobilis (no. 11), Staphylococcus lentus (no.13). ) and Candida ciferrii (M2) fungus were isolated. Granulicatella adiacens (No. 2), Staphylococcus xylosus (No. 10), Sphingomonas paucimobilis (No. 15) and Cryptococcus laurentii (M1) and Candida famata (M3) bacteria from the internal tissues and organs of Polistes dominula paper wasp adults (Debaryomyces, Fungi (also known as Hansensis and Torulopsis candida) were obtained. Staphylococcus xylosus and Sphingomonas paucimobilis were found to be common bacteria in both bee species. Serratia marcescens and Enterococcus faecalis bacterial species were found to have a very lethal effect on honeybees. Bioassay experiments were performed on the detected fungi, and it was observed that Cryptococcus laurentii and Candida famata fungi species also had lethal effects on honeybees. It has been revealed that entomopathogenic bacteria, which are known to be very effective in biological control against harmful insects, can cause unwanted infections in honeybees.

Species traits, landscape quality and floral resource overlap with honeybees determine virus transmission in plant-pollinator networks.

Emerging infectious diseases pose a threat to pollinators. Virus transmission among pollinators via flowers may be reinforced by anthropogenic land-use change and concomitant alteration of plant-pollinator interactions. Here, we examine how species' traits and roles in flower-visitation networks and landscape-scale factors drive key honeybee viruses-black queen cell virus (BQCV) and deformed wing virus-in 19 wild bee and hoverfly species, across 12 landscapes varying in pollinator-friendly (flower-rich) habitat. Viral loads were on average more than ten times higher in managed honeybees than in wild pollinators. Viral loads in wild pollinators were higher when floral resource use overlapped with honeybees, suggesting these as reservoir hosts, and increased with pollinator abundance and viral loads in honeybees. Viral prevalence decreased with the amount of pollinator-friendly habitat in a landscape, which was partly driven by reduced floral resource overlap with honeybees. Black queen cell virus loads decreased with a wild pollinator's centrality in the network and the proportion of visited dish-shaped flowers. Our findings highlight the complex interplay of resource overlap with honeybees, species traits and roles in flower-visitation networks and flower-rich pollinator habitat shaping virus transmission.

Nesting biology of two species of oil-collecting bees of the genus Paratetrapedia s.l. (Apidae: Tapinotaspidini) in Argentina

Nesting biology of two species of oil-collecting bees of the genus Paratetrapedia s.l. (Apidae: Tapinotaspidini) in Argentina

Variation in season length and development time is sufficient to drive the emergence and coexistence of social and solitary behavioural strategies.

Season length and its associated variables can influence the expression of social behaviours, including the occurrence of eusociality in insects. Eusociality can vary widely across environmental gradients, both within and between different species. Numerous theoretical models have been developed to examine the life history traits that underlie the emergence and maintenance of eusociality, yet the impact of seasonality on this process is largely uncharacterized. Here, we present a theoretical model that incorporates season length and offspring development time into a single, individual-focused model to examine how these factors can shape the costs and benefits of social living. We find that longer season lengths and faster brood development times are sufficient to favour the emergence and maintenance of a social strategy, while shorter seasons favour a solitary one. We also identify a range of season lengths where social and solitary strategies can coexist. Moreover, our theoretical predictions are well matched to the natural history and behaviour of two flexibly eusocial bee species, suggesting that our model can make realistic predictions about the evolution of different social strategies. Broadly, this work reveals the crucial role that environmental conditions can have in shaping social behaviour and its evolution and it underscores the need for further models that explicitly incorporate such variation to study the evolutionary trajectories of eusociality.

Toward a Functional Trait Approach to Bee Ecology.

Functional traits offer an informative framework for understanding ecosystem functioning and responses to global change. Trait data are abundant in the literature, yet many communities of practice lack data standards for trait measurement and data sharing, hindering data reuse that could reveal large-scale patterns in functional and evolutionary ecology. Here, we present a roadmap toward community data standards for trait-based research on bees, including a protocol for effective trait data sharing. We also review the state of bee functional trait research, highlighting common measurement approaches and knowledge gaps. These studies were overwhelmingly situated in agroecosystems and focused predominantly on morphological and behavioral traits, while phenological and physiological traits were infrequently measured. Studies investigating climate change effects were also uncommon. Along with our review, we present an aggregated morphological trait dataset compiled from our focal studies, representing more than 1600 bee species globally and serving as a template for standardized bee trait data presentation. We highlight obstacles to harmonizing this trait data, especially ambiguity in trait classes, methodology, and sampling metadata. Our framework for trait data sharing leverages common data standards to resolve these ambiguities and ensure interoperability between datasets, promoting accessibility and usability of trait data to advance bee ecological research.

The role of wild bees and cavity-nesting wasps as ecological indicators of the last traditionally managed meadows in Eastern Europe.

The number of wild bees and cavity-nesting wasps is abundant in agricultural areas and they contribute significantly to ecosystem services. Due to their specialization in nesting sites and food sources, these groups are sensitive to habitat condition changes and they are therefore important indicators for environmental impact assessments. As semi-natural habitats are steadily declining and often understudied, their significance for research is increasingly recognized. During this research, the role of wild bee species and cavity-nesting Hymenopteran taxa as indicators was examined, along the unique combination of high nature value and traditional land use habitats in Eastern Europe, Transylvania. Transects and trap nests were used to test the diversity and abundance of wild bees and cavity-nesting Hymenopterans to identify possible differences between highly protected and less protected areas. The differences in taxonomic groups between the sites and the potential effects of landscape structure on wild bees and cavity-nesting Hymenopterans were also assessed. We detected a high diversity of wild bee species and a significant species replacement from one study year to another. Among the nest-building Hymenopteran taxa, the majority of nests was built by Trypoxylon sp. during both study years, with a stronger dominance in the second year. The different taxonomic groups of wild bees and cavity-nesting Hymenopterans showed differences in their habitat affinities. The majority of the sampled bumblebee species as well as Trypoxylon sp. had an affinity towards the study sites located within the highly protected study area. Altogether, we found different habitat preferences for different Hymenopteran groups (both wild bees and wasps) and conclude that these groups definitely have the potential to serve as indicators for differences in the intensity of land use.

Testing microbial pest control products in bees, a comparative study on different bee species and their interaction with two representative microorganisms

BackgroundThe evaluation of the impact of pesticides on non-target species, like bees, is a crucial factor in registration procedures. Therefore, standardized test procedures have been developed on OECD level assessing the effects of chemicals on honey bees or bumble bees. Unfortunately, these protocols cannot directly be adapted for testing products that contain microorganisms. Interest in the use of microorganisms has increased in recent years due to their specificity to target species while not harming non-target organisms. This study aimed to evaluate optimal conditions to assess the effects of microbial plant protection products on bee species according to currently available test protocols. Some of the most commonly used microorganisms for plant protection, Bacillus thuringiensis subspecies aizawai (B. t. a. ABTS 1857) and Beauveria bassiana (B. b. ATCC 74040) were tested on Apis mellifera, Bombus terrestris, and Osmia bicornis at different temperatures (18, 26, 33 °C) under laboratory conditions.ResultsExposure to the product containing B. t. a. ABTS 1857 resulted in higher mortality compared to B. b. ATCC 74040 in all tested bee species. A temperature-dependent effect towards higher mortality at higher temperatures of 26 °C or 33 °C was observed in O. bicornis exposed to both microorganisms. A. mellifera showed variable responses, but for B. terrestris there was mostly no effect of temperature when exposed to microorganisms in high concentrations. However, temperature affected longevity of bee species in the non-exposed control group. A. mellifera mortality increased with decreasing temperatures, while B. terrestris and O. bicornis mortality increased with increasing temperatures. A test duration of 15 or 20 days was found to be suitable for testing these microorganisms.ConclusionIn conclusion, 26 °C should be considered the worst-case scenario for testing B. bassiana on all tested bee species. For testing B. thuringiensis, a temperature of 33 °C is recommended for A. mellifera, whereas B. terrestris and O. bicornis should be tested at 26 °C.

Effects of urbanization on orchid bee diversity and orchid pollination: From neotropical cloud forests to urban cores

Urbanization is a significant driver of land use change, profoundly impacting biodiversity and ecosystem services worldwide. However, its effects in the tropics, which host some of the planet's highest biodiversity, remain inadequately understood. Orchid bees (Apidae: Euglossini) are key pollinators in Neotropical ecosystems, playing crucial roles in maintaining floral diversity and reproductive success of orchids and other plant families. Yet, little is known about how urbanization influences their diversity and pollination. In this study, we analyzed the diversity and composition or orchid bee communities along an urbanization gradient which extends from the city center to the surrounding cloud forests, which bear high orchid endemism while being highly threatened. Along the same gradient, we further evaluated pollination of a model native orchid, Gongora galeata, which is exclusively pollinated by the bee Euglossa obrima. As expected, increasing urbanization led to a decrease in orchid bee diversity, as well as a clear separation in species composition between urban and non-urban sites and a reduction in G. galeata pollination (i.e. fruit production). However, contrary to our expectations, orchid pollination also decreased with environmental heterogeneity and the abundance of its specific pollinator. Despite urban areas still hosting orchid bee species, our results reveal clear negative effects of urbanization not only on diversity, but also on the ecosystem function of a highly threatened group of bees. This study highlights the importance of considering local factors of urban landscapes for preserving not only biodiversity, but also fundamental ecological processes in cities.