Search Results (86)

Bombus haematurus (Hymenoptera: Apidae), which arrived from the Balkan Peninsula, was first reported in Italy in 2020 in the Friuli Venezia Giulia region (FVG) (northeastern Italy) near the border with Slovenia. To study the spread and biology of the species, a survey was conducted at several sites of the FVG in the period 2023–2025. Bombus haematurus was recorded at 22 new sites across all four districts of the FVG (Trieste, Gorizia, Udine, and Pordenone), indicating its expansion towards the west. Bumblebees of this species were detected in plain and hilly areas at sites between 10 and 364 m a.s.l. They were observed more frequently at forest edges, undergrowth paths or clearings and meadows adjacent to woods, confirming the species is hylophilous. The activity of adults from February to July confirms that the bumblebee is an univoltine spring species. Specimens were observed foraging on the flowers of 19 wild and ornamental plants belonging to 12 families (in particular, Lamiaceae), confirming that the species is polylectic. The data collected indicate that B. haematurus are permanently established in the FVG and that a further spread of the species towards the west in the neighbouring Veneto region is likely. Full article

Pedicularis hallaisanensis is a strictly biennial, hemiparasitic herb endemic to Republic of Korea and listed as an endangered species. Its populations are limited to high-altitude habitats, with recent surveys confirming survival only in Gayasan. This study aimed to assess the population size and ecological traits of P. hallaisanensis to inform conservation strategies. We established 23 quadrats at 1400–1410 m above sea level and collected microhabitat data (air temperature, soil moisture, electroconductivity, vegetation cover, and species richness) from 2022 to 2024. Flora composition and pollinator species were surveyed, with bumblebees (Bombus ignitus, B. hypocrita sapporoensis) identified as the most frequent pollinators. General linear mixed models and Pearson’s correlation analysis showed a strong positive relationship between species richness and population size and between vegetation cover and stem height. The study area’s average temperature was 6.3 °C below Republic of Korea’s national average, suggesting that climate change could disrupt the microclimatic conditions necessary for this species’ survival. The findings highlight the importance of maintaining plant diversity and controlling invasive woody species to sustain P. hallaisanensis populations. Targeted conservation measures, including habitat management and ex situ propagation, are recommended to safeguard this vulnerable species. Full article

Pesticides are considered a major factor in the decline of bee populations. Flupyradifurone, a novel insecticide, is believed to be relatively ‘bee-safe’. This study aims to evaluate the acute and chronic toxicity of flupyradifurone and assess its risks to both commercial bumblebee Bombus terrestris and the Asian native species B. lantschouensis. Oral toxicity tests demonstrated species-specific sensitivity, with B. lantschouensis exhibiting 5.4-fold higher acute toxicity (72-h LD₅₀: 5.1 μg/bee vs. 28 μg/bee) and 3-fold lower chronic toxicity (No Observed Adverse Effect Concentration, NOAEC: 20 μg/mL vs. 60 μg/mL) compared to B. terrestris. Risk assessments indicated low Hazard Quotients (HQ) of 4 for B. terrestris and 20 for B. lantschouensis. However, the Exposure Toxicity Ratio (ETR) values from both screening and first-tier assessments exceeded the trigger levels, necessitating further testing. This study provides crucial data on the acute and chronic toxic effects of flupyradifurone and highlights the need for more comprehensive insecticide risk assessments, particularly for non-Apis pollinators, to better protect these vital species. Full article

Understory flowering plants often face limitations in pollinator availability. This necessitates an investigation of pollination mechanisms and reproductive traits to understand their survival strategies. Floral syndromes, which are critical determinants of plant–pollinator coevolution, significantly impact the reproductive success and diversification dynamics of angiosperms. The genus Impatiens is known for its remarkable floral diversity and varied pollination systems and it is also serves as an exemplary model for examining plant–pollinator interactions. Therefore, this study was performed to elucidate the pollination characteristics and breeding systems of three sympatric species, Impatiens davidii, Impatiens jinggangensis, and Impatiens commelinoides. The results indicated all the Impatiens species exhibited similar individual flower longevity (4–5 days). However, I. commelinoides and I. jinggangensis peaked in July-August, whereas I. davidii primarily flowered in August-September. These species shared a self-compatible breeding system that requires pollinators for facultative outcrossing, with bumblebees (Bombus) and polyester bees (Amegilla) identified as the primary pollinators. The presence of wing petals had a significant impact on fruit set in both I. davidii and I. commelinoides. The three Impatiens species demonstrated notable interspecific differences in their floral scent profiles, accompanied by distinct variations in floral morphology and scent characteristics. These differences collectively represent pollination strategies and life-history tactics that highlight pronounced interspecific divergence. The variation in pollination strategies is attributed to the synergistic interaction between floral morphology and scent chemistry. Thus, these findings offer valuable insights for the investigation of forest understory plant conservation, resource utilization, and co-evolutionary relationships with primary pollinators. Full article

To clarify the pollination contributions of introduced honey bees and native wild bees, we compared their pollination efficiency on a perennial herb, Polygonatum cyrtonema Hua. The flower’s traits and bees’ body traits were measured to quantify the mechanical fit between the bee species and flower. Pollen removal and deposition per visit, visit frequency, and visit duration per flower were investigated. The results show that both native bumble bees (worker bees of Bombus trifasciatus Smith) and introduced honey bees (Apis mellifera L.) are effective pollinators, but bumble bees play a more important role in pollination, due to their higher visit frequency and slightly higher pollen transfer efficiency. The bumble bees removed and deposited significantly more pollen grains per visit than the honey bees (both p < 0.001). The faster visiting speed and shorter visit duration of the bumble bees, combined with their larger body size and longer proboscises, may have contributed to their higher pollen transfer efficiency. The pollination success of P. cyrtonema depends on its pollinators. This study is the first to report on the pollination efficiency of floral visitors on P. cyrtonema. Our findings highlight the importance of conserving native bumble bee populations to ensure the reproductive success of P. cyrtonema. Future studies should focus on their management to minimize potential disruptions to native pollination contribution. Full article

Bumblebees, the most important wild pollinators in both agricultural and natural ecosystems, are declining worldwide. The global decline of bumblebees may threaten biodiversity, pollination services, and, ultimately, agricultural productivity. Several factors, including pesticide usage, climate change, habitat loss, and species invasion, have been documented in the decline of bumblebee species, but recent studies have revealed the dominating role of pathogens and parasites over any of these causes. Unfortunately, there is a lack of a full understanding of the role of pathogens and parasites in the decline of bumblebee species. The current study provides a comprehensive review of how pathogens and parasites contribute to the decline of bumblebee species. The study also explores the prevalence of each pathogen and parasite within bumblebee populations. Furthermore, we address the synergistic effects of pathogens and other stressors, such as pesticides, climatic effects, and habitat loss, on bumblebee populations. To summarize, we propose possible conservation and management strategies to preserve the critical role of bumblebees in pollination services and thus to support ecosystem and agricultural health. Full article

The native biodiversity of oceanic islands is threatened by human-driven disturbance and by the growing number of species introductions which often interfere with natural ecological processes. Here, we aim to evaluate the effect of anthropogenic disturbance on plant–pollinator interactions in the native forest communities of an oceanic island (Terceira, Azores, Portugal). We found that native species predominated in preserved sites compared to disturbed ones and that the extant plant–pollinator interactions were mostly dominated by generalist species. Dipterans, particularly hoverflies, emerged as the primary flower visitors, while introduced hymenopterans (Apis mellifera and Bombus terrestris) and native beetles were locally important, respectively, in disturbed and preserved sites. Human-driven disturbance seems to be responsible for the observed differences in flower abundance and species composition between sites and to drive changes in specific network metrics (namely nestedness, interaction strength asymmetry, and specialization), particularly in one of the study areas. Our findings also suggest that native generalist species provide ecological opportunities that can facilitate the establishment of introduced species through their broad interaction networks. Full article

Monitoring declining species is crucial to inform conservation but is challenging for rare species with limited information. The Western Bumble Bee (Bombus occidentalis) was previously common in the western United States but has drastically declined. Despite documented populations in the Intermountain West, many areas remain under-sampled. Species distribution models (SDM) can guide sampling efforts in large areas by predicting where the highest probability of suitable habitat may occur. We developed a sampling SDM using historical observations (1910–2010) in Wyoming to predict suitable habitat in the past. Using the model, we selected sampling sites that ranged from low to high predicted habitat suitability and we revisited historical locations where B. occidentalis were observed. Using all data (historical and current), we selected the predictors that explained the most variance, and created separate historical and current (2017–2018) SDM using the same variables to assess how predicted habitat suitability changed. We detected B. occidentalis at 30% of the revisited historical sites and 25% of all sites sampled. Areas predicted to be highly suitable for B. occidentalis in Wyoming declined by 5%; a small decrease compared to declines in the western portion of their range. Predicted habitat suitability increased the most in foothill areas. Creating SDM with landscape and climatic variables can bolster models and identify highly contributing variables. Regional SDM complement range-wide SDM by focusing on a portion of their range and assessing how predicted habitat changed. Full article

Bumblebee species are vital wild pollinators, providing essential pollination services for various crops, fruits, and vegetables. However, their biodiversity is vulnerable to decline due to climate change, particularly in regions like northern Pakistan. Despite this, no research has yet been conducted on the distribution patterns of bumblebee species in this region. The current study aimed to model the spatial distribution of three important bumblebee species: Bombus haemorrhoidalis, B. rufofasciatus, and B. subtypicus in northern Pakistan. Habitat suitability and the contribution of bioclimatic variables to the spatial distribution of species were assessed using the MaxEnt approach. Current and future bioclimatic variables, along with presence-only records of three bumblebee species, were incorporated into the species distribution model. The results indicated that nearly 96% of the area (43 out of 45 cities in northern Pakistan) showed habitat suitability for all three species in the current scenario. Among these 43 cities, five exhibited a 100% overlap in suitable areas for the three species. However, this overlap area is expected to decrease in the future, particularly by the middle of the 21st century, highlighting these regions as prime candidates for conservation. In terms of bioclimatic factors influencing spatial distribution, the study found that temperature-related variables played a more significant role than precipitation-related ones in current and future scenarios. Specifically, bio3 (isothermality) contributed 48% to B. haemorrhoidalis and 43% to B. rufofasciatus, while bio2 (mean diurnal range) was the most influential factor for B. subtypicus. Temperature-related variables accounted for more than 80%, 69.4%, and 78.3% of the spatial variation in B. haemorrhoidalis, B. rufofasciatus, and B. subtypicus, respectively. This study demonstrates the critical influence of temperature on the spatial distribution of bumblebee species in northern Pakistan, underscoring the need for climate-focused conservation strategies to protect these important wild pollinators. Full article

To understand the reproductive strategies of the typically introduced plant Hibiscus mutabilis and to compare the pollination efficiency of its different pollinators, we observed, measured, and recorded the flowering dynamics, floral traits, and visiting insects of H. mutabilis. Furthermore, we compared the body size, visitation rate, and pollination efficiency of the pollination insects of H. mutabilis. The results indicated that, despite exhibiting specialized moth pollination characteristics based on similarities in flower features to other moth-pollinated species, H. mutabilis actually presented a generalized pollination system. The nectar of H. mutabilis attracted a variety of insects to provide pollination services, a total of five flower visitors, one moth species (Macroglossum pyrrhosticta), and four bee species (Xylocopa appendiculata, Xylocopa dissimilis, Bombus breviceps, and Apis mellifera), were found to provide pollination services for H. mutabilis. The pollination efficiency of these pollinators was related to the parts of their body in contact with the stamens and stigmas of flowers. Although M. pyrrhosticta was larger in size and its visitation frequency in our field observations was higher, its pollination efficiency was lower. This was due to the small part of its body (proboscis) contacting the two sexual organs of H. mutabilis while visiting flowers, resulting in a low amount of pollen being transferred and deposited. In contrast, the bee pollinators’ proboscis was significantly shorter than that of M. pyrrhosticta, and it must enter the flower to suck the nectar that is hidden deeply inside the base of the flower. Therefore, the body parts of bee pollinators in contact with the two sexual organs of H. mutabilis were larger than M. pyrrhosticta in the process of visiting flowers, and the pollination efficiencies were significantly higher than those of M. pyrrhosticta. In addition, larger bee pollinators have higher pollination efficiency. As a result, H. mutabilis suffered from pollen limitation due to the pollination efficiencies of the moth pollinators in the introduced habitats, but it compensated by attracting more species of bee pollinators. Full article

We assessed if the commercially reared South American bumblebee Bombus pauloensis forages resources in alfalfa crops by monitoring their colony activity daily. We analyzed the pollen collected by using pollen traps specifically designed for B. pauloensis nests and counted the number of bumblebees in the crop. Consequentially, colony activity was found to be highest during the mornings; 65% of the pollen trap samples analyzed contained alfalfa pollen grains, and 60% of the total pollen loads were identified as alfalfa pollen. Although the honey bee was the predominant pollinator observed in the crop, the high percentage of alfalfa pollen found in the pollen traps of B. pauloensis nests suggests that this species forages resources in alfalfa crops and could be considered a potential managed pollinator. Full article

The pollination characteristics and flowering phenology of Calanthe sieboldii were evaluated to elucidate its reproductive characteristics and breeding systems. Field observations and artificial pollination experiments were conducted to study the pollination biology in Xuancheng City, Anhui Province. Meanwhile, gas chromatography–mass spectrometry (GC-MS) was employed to analyze the species’ volatile organic compounds (VOCs). Key findings include the following: (1) the flowering period extends from mid-April to mid-May, with a population-level flowering duration of 29 days in 2017, individual plant flowering averaging 20.22 days, and single flower longevity ranging from 12 to 23 days (mean = 19.30 days); (2) the species exhibits deceptive nectar guides devoid of nectar, indicating food-deceptive pollination, with Bombus sp. identified as its primary pollinator; (3) the pollinial–ovule ratio and hybridization index suggest a high level of self-compatibility without autonomous self-pollination, with no significant difference in pollination success between self- and outcross populations; (4) GC-MS analysis identified methyl benzoate and acacia-related compounds as the primary VOCs of C. sieboldii. These findings provide valuable insights into the conservation and sustainable management of orchids, particularly C. sieboldii. Full article

To understand the processes behind pollinator declines and for the conservation of pollination services, we need to understand fundamental drivers influencing pollinator behaviour. Here, we aimed to elucidate how wild bumblebees interact with three plant species and investigated their foraging behaviour with varying flower densities. We video-recorded Bombus terrestris in 60 × 60 cm quadrats of Lotus creticus, Persicaria capitata, and Trifolium pratense in urban areas of Terceira (Azores, Portugal). For the automated bumblebee detection and counting, we created deep learning-based computer vision models with custom datasets. We achieved high model accuracy of 0.88 for Lotus and Persicaria and 0.95 for Trifolium, indicating accurate bumblebee detection. In our study, flower cover was the only factor that influenced the attractiveness of flower patches, and plant species did not have an effect. We detected a significant positive effect of flower cover on the attractiveness of flower patches for flower-visiting bumblebees. The time spent per unit of inflorescence surface area was longer on the Trifolium than those on the Lotus and Persicaria. However, our result did not indicate significant differences in the time bumblebees spent on inflorescences among the three plant species. Here, we also justify computer vision-based analysis as a reliable tool for studying pollinator behavioural ecology. Full article

Public lands, managed for multiple uses such as logging, mining, grazing, and recreation, also support vital environmental services like wild bee pollination. A trending decline in wild bees has heightened interest in documenting these key pollinators in their native habitats. Accurate assessment of pollinator community diversity is crucial for population monitoring and informing land management practices. In this study, we evaluate the efficiency of Malaise traps and pan traps in sampling wild bees over three growing seasons in subalpine meadow communities in central Utah. Sixteen trapping sites were established, each with a Malaise trap and an array of blue, white, and yellow pan traps, nine at each site. Weekly collections were made through summer months and a comparison of their effectiveness in capturing bee abundance and species richness was made. Malaise traps captured significantly greater abundance of bees on average, though this was species-dependent. Malaise traps were especially effective at capturing Bombus spp. and larger species. Pan traps were generally more effective with smaller species such as Hylaeus spp. White pan traps outperformed yellow and blue pan traps in terms of abundance and only yellow pan traps in terms of richness. Both methods contributed unique species to the overall collection effort, suggesting that a combination of trapping methods provides a more comprehensive understanding of bee communities. Species accumulation curves indicate that species existing within the community went unencountered in our samples and that more time or perhaps additional methods could aid in best describing the entire community. Full article

Fritillaria spp., comprising perennial bulbous plants of significant medicinal and ornamental value, face high endangerment in their natural habitats. Despite their importance, the reproductive characteristics and adaptive evolution mechanisms of these species remain incompletely understood. This study focused on the pollination strategies and reproductive biology of Fritillaria imperialis L. The research was conducted at the Erzincan Horticultural Research Institute in Türkiye. Our investigation categorized the flowering process of F. imperialis into nine distinct phases. Through comprehensive assessments of the pollen/ovule ratio, self-incompatibility index (SII), and ex situ pollination experiments, we observed high levels of self-incompatibility and allogamy in F. imperialis. Our findings revealed that pollination of F. imperialis primarily relied on pollen vectors, with Apis mellifera and Bombus terrestris identified as the most effective pollinators. Furthermore, average seed set rate, seed production, and seed viability were quantified at 80.5%, 228 seeds, and 86.3%, respectively. The average numbers of pollen viability and pollen grains were measured at 93% and 702,000, respectively. This comprehensive analysis of the reproductive biology of F. imperialis provides crucial insights for the conservation and genetic management of this highly valuable species. The findings contribute to a deeper understanding of the reproductive strategies employed by Fritillaria spp., which may inform future conservation efforts and breeding programs for these endangered plants. Full article