Search Results (194)

Human-driven land use change and intensification is a major threat to global biodiversity. High levels of land management intensity may reduce species diversity, change the composition and structure of plant and animal communities and disrupt ecological processes. However, there is still scarce information on the impacts of land management intensity on island pollinator communities and their interactions with plants. Here, we aim to assess how different land use types (natural vegetation, semi-natural pastures, and intensive pastures), representing a gradient of grazing intensification, influence pollinator diversity and plant–pollinator interactions on Terceira Island (Azores). We surveyed 30 sites (10 per land use) and recorded 1453 visits by 41 pollinator species. Alpha diversity did not differ among land uses, but grazing intensification reduced the abundance of several native species while favoring some exotics, such as the honeybee. Network analyses showed changes in structural properties and declines in interactions between native species with increasing grazing disturbance. Introduced species, particularly the honeybee, dominated interactions in intensively managed habitats, replacing native species from key ecological roles. Our findings highlight the vulnerability of island ecosystems to grazing intensification and emphasize the need for conservation measures in the Azores, namely the reduction in grazing intensity, restoration of habitat connectivity, and implementation of pollinator-friendly agri-environmental schemes to enhance native biodiversity and sustain ecosystem services. Full article

Understanding wild bee diversity is critical for pollinator conservation, particularly in understudied tropical regions like coastal Ecuador. This preliminary study provides a photography-based assessment of bee diversity at Finca Botánica, an organic and regenerative farm on Ecuador’s central Pacific coast. Over a 10-day survey in December 2024, researchers documented 51 bee species across four families, with Apidae being the most represented. The study highlights a predominance of solitary, ground-nesting bees and a lower-than-expected diversity of Meliponini (stingless bees) and Euglossini (orchid bees) compared to other regions of Ecuador. Many species were found in forest patches, ecological corridors, and cover-cropped maize fields, underscoring the role of sustainable farming practices in supporting pollinator diversity. While photographic methods provided valuable preliminary data, they also revealed limitations in species-level identification, reinforcing the need for future specimen-based surveys. These findings suggest that Ecuador’s dry coastal forests may harbor a richer bee community than previously recognized and that organic farms can serve as important refuges for native pollinators. Full article

Tea oil tree (Camellia oleifera), a woody oil crop native to Southern China, relies on insect pollination for fruit and seed production. However, its nectar is toxic to honey bees (Apis spp.) due to their inability to digest the oligosaccharide present in the nectar. This toxicity raises concerns about the trade-off between the benefits of pollination and the risks posed by exposures to toxic nectar. We aimed to investigate whether tea oil tree yield is enhanced by honey bee pollination, while also examining the impact of nectar toxicity and exploring potential mitigation methods. We evaluated the fruit set, seed yield, and oil quality of the crop with or without eastern honey bee (A. cerana) pollination during 2019–2022. We also characterized nectar oligosaccharide compositions collected from both flowers and bee hives. We administered α-galactosidase (an enzyme to promote oligosaccharide digestion) onto bee larvae fed with crop nectar. We found that A. cerana could significantly enhance fruit set and seed yield. The administration of α-galactosidase could enhance larval survivorship challenged by nectar toxicity. The effectiveness of honey bee pollination can vary between years, with warmer temperatures significantly enhancing honey bee pollination benefits. The results suggest that a decision to use honey bees for pollinating tea oil trees should involve consideration of the impact of local weather conditions, as low temperatures may compromise pollination benefits while increasing risks posed by toxic nectar. The administration of digestive enzymes to honey bees shows potential for mitigating natural toxins in tea oil tree nectar. Full article

Tall fescue-dominated pasturelands are widespread in the eastern United States and typically lack substantial plant diversity. Establishing native wildflowers into tall fescue pastures has the potential to benefit bee populations and boost pollinator ecosystem services. In this study, tall fescue pastures at five on-farm sites in Virginia, USA, were planted with wildflowers native to North America and paired with sites with conventional tall fescue pastures. Honeybee apiaries were established at the ten locations, and variables related to hive strength were measured over two years. The main study objectives were to: (1) compare metrics of hive strength between diversified and conventional pastures, (2) determine whether honeybees used native-sown wildflowers as a source of pollen, and (3) explore whether native-sown wildflowers were visited more by honeybees and other pollinators compared with nonnative, unsown forbs. Diversified pastures had many more plant species and blooms compared with conventional pastures, but this had little effect on hive parameters. Pollen DNA metabarcoding revealed that honeybee diets were similar regardless of whether hives were associated with diversified or conventional pastures. Honeybees foraged mostly on plants in the surrounding landscape—especially white clover (Trifolium repens) and less so on native wildflowers. Native-sown wildflowers received more visits from native pollinators, however. We hypothesize that the native-sown wildflowers had little impact on hive strength metrics because honeybees had access to abundant, white clover blooms and other flowering species in these landscapes. Native wildflowers that bloom in late summer/early autumn after white clover blooms diminish may be of greater value to honeybees in pasture settings. Full article

Apricot (Prunus armeniaca L.) exhibits a gametophytic self-incompatibility (GSI) system. To identify the S-genotypes of the main apricot cultivars, including 133 native Chinese cultivars and 35 foreign accessions, PCR was performed using a combination of five primers based on the conserved regions of Prunus S-RNase genes. After cloning and sequencing the PCR products, the S-genotypes of all 168 apricot cultivars were determined. A total of 46 different S-RNase alleles, with 15 new alleles, were identified. For all 168 accessions, the top five most frequent S-alleles were S₈, S₁₁, S₉, S₁₆, and S₅₃. S₁₁, S₈, and S₁₆ were the most frequent in Chinese cultivars, and S₉, S₈, and S₂ were mostly found in European accessions. For Chinese apricot cultivars, the distribution of S-alleles among five geographic regions was also investigated. In Northwest China, S₁₆ was the most frequent S-allele. In the Xinjiang region, S₆₆, S₄₉, and S₁₄ were the top three most frequent S-alleles. In North China, S₈, S₁₁, and S₅₃ were the top three most frequent S-alleles. In addition, the self-compatible type, S_C, was not detected in these 133 Chinese accessions. Finally, the phylogenetic tree of apricot S-alleles indicated that there are four groups of S-RNase genes (S₉₇/S₁₀₆, S₁₄/S_14a/S₆₆, S₉/S₁₇/S₄₄, and S₂₃/S₅₃) presenting a very close relation. These results provide more data on the S-genotypes of apricot accessions, which can support future breeding programs by aiding in the selection of the appropriate parents and contributing to efficient orchard design by combining cultivars with suitable pollinizers. Full article

Over the past few decades, the western honeybee (Apis mellifera) has been widely introduced throughout China. Introduced honeybees have often been observed to pose a significant threat to native bee species diversity through competition for floral resources. However, the specific impact on native pollinator communities is not well understood, especially in alpine meadows, where bee diversity is particularly high. In this study, we determined the difference in species abundance and diversity of native bees between nearby and distant plots relative to apiaries in alpine meadows on the eastern Tibetan Plateau. We constructed a plant–bee network and calculated perceived apparent competition (i.e., the feeding niche overlap) between the introduced honeybees and each of the native bee species. Furthermore, we determined the relationship between the relative change in species abundance and the perceived apparent competition and species abundance across bee species. Among the 15 native bee species, 9 bee species were significantly lower in abundance in the nearby plots compared to the distant plots, and, in particular,, 5 rare species were not found in the nearby plots. For the other six species, the abundance difference was statistically non-significant. Data analysis reveals that the species abundance of native bees in distant plots, along with the feeding niche overlap between introduced bees and native bees in distant plots, explains the variation in the relative change in species abundance across bee species. However, the feeding niche overlap between introduced bees and native bees in nearby plots does not account for this variation. Our findings demonstrate that rare native bee species with greater feeding niche overlap have been significantly impacted by the introduced western honeybees. These results highlight important implications for pollinator management in natural ecosystems and the conservation of wild bees. Full article

Bees are vital pollinators that maintain plant populations by transporting pollen among individuals; however, bees are declining, and information on how habitat characteristics alter the catch of bees in traps is needed to better assess monitoring. Few studies have measured how catch in passive traps may be altered by floral resources despite the well-known dependence of pollinators on forbs. We investigated the degree to which pollinating insects were attracted to vane traps and bee bowls placed at sites that varied in flower densities (0–800 flowers/m²). We also assessed if the catch of bees was better explained by flower characteristics directly around traps (subsite) or average flower characteristics at a site. Floral density, richness and surface area were measured in 1 m² quadrats at each subsite. The surface area of flowers explained more variance in bees captured compared to the density or richness of flowers. Traps placed in areas with lower flower surface area captured the more bees and a more diverse sample. Floral resources at the subsite and site explained a similar amount of variance in the number of bees captured, suggesting that pollinators respond to flowers at both scales. We provide a method of correcting pollinator abundance by flower surface area to make catch in passive traps more comparable among areas. We can select sites that minimize or maximize the catch of bees by understanding how floral resources change the effectiveness of passive traps. Full article

Kiwifruit (Actinidia deliciosa) is a globally important crop presenting challenges for ensuring cross-pollination. This study aimed to (1) record the entomological fauna visiting flowers; (2) evaluate the visitation frequency of pollinators; and (3) test the use of lavender extract to enhance cross-pollination by honeybees and assess the impacts on fruit quality. Nine species of floral visitors were recorded as pollinators, although the most frequent were the exotic honeybee (Apis mellifera) and the native bees Bombus pauloensis and Xylocopa augusti. Honeybees increased their visitation to flowers when the attractant was used, improving pollination service and fruit quality compared to the control-bagged treatment, resulting in fruits that were 20 g heavier (115.4 g vs. 95.6 g, 95% CI). Similarly, the number of seeds per fruit and the fruit shape index (FSI) increased in treatments exposed to bee visitation when compared to the bagged control. However, differences in bee visitation among treatments suggested a non-linear relationship between bee activity and fruit quality. Nevertheless, achieving high-quality fruit standards across treatments could be explained by the extended floral lifespan, which allowed for a high number of visits and ensured pollination. Finally, we did not observe any bias in honeybee visitation by applying sugar syrup combined with the attractant. Hence, to increase honeybees’ visits to flowers, we recommend applying the scent directly in a water solution. Full article

Northward expansion of economically essential plants is a vital strategy for enhancing agricultural productivity; however, it often results in reduced yields. This study systematically assessed the impact of translocating the high-value oilseed species Camellia hainanica from its native tropical habitat Sanya to the temperate cultivation area of Changsha, focusing on its reproductive processes, including flowering, pollination, and fruit development. Our findings revealed a 45-day delay in anthesis at the transplanted location, which was associated with notably lower average daily temperatures (7.89 °C in Changsha compared to 24.63 °C in Sanya) during the anthesis period. While floral longevity, stigma receptivity, and pollen viability remained comparable between sites, anther dehiscence was markedly delayed by three days after transplanting. Crucially, pollinator visitation during peak flowering plummeted by 92% compared to the levels in Sanya, and a 57% reduction in pollen deposition on stigmas occurred. Consequently, natural fruit sets in Changsha collapsed to 0%, significantly lower than those in Sanya, despite artificial cross-pollination achieving an 11% fruit set rate. These results and the pollination deficit coefficient (D = 1.00) all demonstrate that severe pollination deficits are the key limitation causing reproductive failure in northward-expanded C. hainanica orchards. Addressing these yield constraints necessitates targeted breeding for earlier flowering genotypes and implementing pollination management strategies. Full article

This study aims to characterize for the first time the insect assemblage associated with sown, introduced guayule (Parthenium argentatum A. Gray, Asteraceae) in Castilla-La Mancha, Spain, and identify potential relationships with the crop. Insect sampling was conducted using nets and pan traps during spring and early summer, coinciding with the flowering period of the plant. A total of 352 insect species/morphospecies across 12 orders were identified. Diptera, Coleoptera, Hemiptera, and Hymenoptera were the most species-rich and abundant orders. Within these orders, Muscidae, Syrphidae, Tenebrionidae, Dermestidae, Miridae, Halictidae, and Apidae were the most numerous families. Guayule flowering intensity increased gradually until mid-June, aligning with the peak activity of pollinating Diptera. The majority of the identified insects (74.4%) were potential pollinators, while nearly 50% were detritivores and approximately 30% were herbivorous. The similarity in insect families and functional roles observed in this study to previous studies in the USA and Mexico suggest that guayule may serve as a similar trophic resource for insects in Spain, despite being a non-native species. Full article

Anthropogenic noise can have diverse effects on natural ecosystems, but less is known about the degree to which noise can alter organisms in comparison to other disturbances. A variety of frequencies are produced by man-made objects, ranging from high to low frequencies, and we studied infrasound (<20 Hz) produced by wind turbines and trains. We estimated the number, mass and viability of seeds produced by flowers of Plains pricklypear (Opuntia polyacantha Haw.) that were left open to pollinators, hand-pollinated or bagged to exclude pollinators. Each pollination treatment was applied to plants at varying distances from wind turbines and railways (≤25 km). Self-pollinated Opuntia polyacantha and plants within the wind facility produced ≥1.6 times more seeds in the bagged treatments compared to more distant sites. Seed mass and the percent of viable seeds decreased with distance from infrasound. Viability of seeds was >70% for most treatments and sites. If wind facilities, railways and other man-made structures produce infrasound that increases self-pollination, crops and native plants near sources may produce heavier seeds with higher viability in the absence of pollinators, but genetic diversity of plants may decline due to decreased cross-pollination. Full article

Nature-based Solutions (NbS) are increasingly adopted in urban settings to restore ecological functions and enhance biodiversity. This study evaluates the effects of NbS interventions on bird, insect, and plant communities in the Cavalum Valley urban green area, Penafiel (northern Portugal). Over a three-year period, systematic field surveys assessed changes in species richness, abundance, and ecological indicators following actions such as riparian restoration, afforestation, habitat diversification, and invasive species removal. Results revealed a marked increase in bird overall abundance from 538 to 941 individuals and in average pollinator population size from 9.25 to 12.20. Plant diversity also improved, with a rise in native and RELAPE-listed species (5.23%). Functional group analyses underscored the importance of vegetative structure in supporting varied foraging and nesting behaviours. These findings highlight the effectiveness of integrated NbS in enhancing biodiversity and ecological resilience in urban landscapes while reinforcing the need for long-term monitoring to guide adaptive management and conservation planning. Future work could evaluate ecological resilience thresholds and community participation in citizen science monitoring. Full article

Urban green spaces are increasingly recognized as important habitats for pollinators, and wildflower seed mixes marketed as pollinator-friendly are gaining popularity, though their actual conservation value remains poorly understood. This study provides the first systematic screening of commercially available seed mixes in Portugal, evaluating their taxonomic composition, origin, life cycle traits, and potential to support pollinator communities. A total of 229 seed mixes were identified. Although these have a predominance of native species (median 86%), the taxonomic diversity was limited, with 91% of mixes comprising species from only one or two families, predominantly Poaceae and Fabaceae, potentially restricting the range of floral resources available to pollinators. Only 21 seed mixes met the criteria for being pollinator-friendly, based on a three-step decision tree prioritizing native species, extended flowering periods, and visual diversity. These showed the highest percentage of native species (median 87%) and a greater representation of flowering plants. However, 76% of all mixes still included at least one non-native species, although none is considered invasive. Perennial species dominated all seed mix types, indicating the potential for the long-term persistence of wildflower meadows in urban spaces. Despite their promise, the ecological quality and transparency of the seed mix composition remain inconsistent, with limited certification or information on species origin. This highlights the need for clearer labeling, regulatory guidance, and ecologically informed formulations. Seed mixes, if properly designed and implemented, represent a largely untapped yet cost-effective tool for enhancing the pollinator habitats and biodiversity within urban landscapes. Full article

Lavandula angustifolia Mill., lavender, is an aromatic plant in the Lamiaceae family. Lavender, which is native to the Mediterranean region but cultivated throughout the world, is an important economic plant. Several studies have investigated two aspects of this aromatic plant: (1) which pollinators, particularly bees, pollinate lavender, and (2) the composition of lavender essential oil. However, little research has been conducted to investigate how pollination affects either the yield or phytochemistry of lavender. The current study, which was conducted in North America, investigates which bee species visit lavender and how pollination affects plant chemistry, specifically the essential oil produced by lavender. Over the course of the 5-week observational period, a total of 12 species (across 10 genera) of bees were identified visiting lavender. Compared to previous studies on cultivated lavender at the same site (Mt. Nebo Botanical Farm, Mona, UT), four bee species not previously observed on lavender were identified. These included Hoplitis producta, Nomada sp., Osmia trevoris, and Megachile snowi. Pollinated lavender, compared to lavender excluded from pollinators, produced more essential oil (yield (w/w) = 1.49% vs. 1.07%), lower relative amounts of linalool (35.4% vs. 39.9%), and higher relative amounts of linalyl acetate (21.3% vs. 16.8%). The findings of this study demonstrate the ecological interactions between pollinators and lavender, and how those interactions impact phytochemistry. Full article

Wildfires are increasing in extent and severity under anthropogenic climate change, with potential adverse impacts on native pollinators like wild bees. In 2019/2020, wildfires burned swathes of the Australian bushland. Whilst herbaceous angiosperms may flower in the post-fire environment, providing sustenance to native bees, pre-made holes created by wood-boring beetles that obligate cavity-nesting “renter” bees may take a longer time to recover. This may prevent native bees from colonising new areas or reduce the populations that have survived. To date, trap-nests, also known as bee hotels, have never been used as a tool to assist in providing nesting resources in post-fire environments. The project “Bee hotels to boost bees after bushfires” supported the recovery of native bee populations by installing artificial nesting substrates (bee hotels) in areas of high biodiversity value that were impacted by the 2019/2020 bushfires. This was achieved through monitoring of 1000 bee hotels (500 bamboo and 500 wooden) and visual surveys at five burnt sites and three control sites (nearby burnt sites without bee hotels) by a native bee ecologist from September–March 2021/2022. The bee hotel uptake was low initially, but by March, all hotels were occupied. Over 800 nests were created by bees in the bee hotels installed for this project and significantly more bees were observed in sites with bee hotels compared to control sites. Across sites, there was a significant negative association between honeybee density and nest occupancy, suggesting honeybees may be exerting competitive pressure on native bees in post-fire habitats. In conclusion, bee hotels, if designed correctly, can aid in boosting cavity-nesting bee populations following fires. Full article