Native Bee Species Research Articles

Attenuation of carrageenan-induced hind paw edema and plasma TNF-α level by Philippine stingless bee (Tetragonula biroi Friese) propolis.

Despite decades-long existence of the Philippine stingless bee industry, the biological activity of propolis from this native bee species (Tetragonula biroi Friese) remains poorly understood and sparingly investigated. Herein, we examined the potential anti-inflammatory efficacy of Philippine stingless bee propolis using the lambda (λ)-carrageenan-induced mice model of hind paw edema. Thirty (30), six-week-old, male ICR mice were randomly assigned into three treatment groups (n=10/group) as follows: distilled water group, diclofenac sodium group (10 mg/kg), and propolis group (100 mg/kg). All treatment were administered an hour prior to the injection of the phlogistic agent. As observed at 3 h post-injection, λ-carrageenan remarkably evoked the classical signs of hind paw edema exemplified grossly by swelling and hyperemia. The ameliorative effect of propolis became apparent at the onset of 6 h post-injection with a statistically significant finding evident at the 24-h period. This gross attenuation histologically correlated to a considerable and specific reduction of the dermal edema, which mirrored those of the diclofenac sodium group. Furthermore, both propolis and diclofenac sodium significantly attenuated the λ-carrageenan-induced increase in the protein expression levels of the pro-inflammatory cytokine tumor necrosis factor-α (TNF-α) depicting more than two-fold decrement relative to the distilled water group. Altogether, these suggest that Philippine stingless bee propolis also exhibited a promising in vivo anti-inflammatory property, which can be partly mediated through the inhibition of TNF-α.

Native bee diversity and abundance in an urban green space in Bengaluru, India

Aim: The aim of the present study was to estimate the diversity and abundance of native bee fauna in an urban green space in Bengaluru, India. Methodology: Native bees were sampled from ten observational plots randomly selected from a 20 ha urban green space. Bee diversity and abundance were recorded at 15-day interval and estimated using diversity indices. Results: Nineteen species and thirteen genera under Apidae, Halictidae, and Megachilidae family were recorded. Bee species under Apidae were the most abundant, with four social, five solitary, and one kleptoparasitic species, followed by Halictidae and Megachilidae, with five and four solitary bee species, respectively. Trigona iridipennis was the dominant species followed by Apis dorsata among the social bees, and Lasioglossum sp. and Hriades sp. were dominant among the solitary bees. The number of cavity-nesting species was more that of tree-nesting or ground-nesting species. Shannon’s and Simpson’s diversity indices confirmed the species richness, species abundance, and uniform distribution of native bee species in the urban green space. Interpretation: Green patches within urban areas can support a diverse population of bees. The study area consisted of both social and solitary bees. Cavity-nesting and oligolectic generalist bees were more predominant in the urban area, thus confirming the role of urban spaces in adding to bee diversity. Green pockets within urban areas support a diverse population of bees, and urban green spaces and green corridors can help to conserve bee biodiversity and, in turn, the urban ecosystem.

Changes in innate immune response and detoxification in Melipona quadrifasciata (Apinae: Meliponini) on oral exposure to azadirachtin and spinosad

Exposure to agrochemicals and pathogens has been indicated as critical factors of declining pollinator populations, including species of native tropical bees. In the present study, we investigated the sublethal effects of acute oral exposure to azadirachtin and spinosad bioinsecticides on the expression of immunity-related genes and the number of hemocytes in uninfected and Escherichia coli–infected workers of the stingless bee Melipona quadrifasciata. Expression of the immune-related gene vitellogenin decreased and the number of circulating hemocytes increased in bioinsecticide-exposed uninfected bees and in unexposed E. coli–infected bees as compared with unexposed uninfected bees. Our results show that though bioinsecticides are considered safe, contamination by sublethal doses of azadirachtin and spinosad can interfere with the immune system of bees.

Flower biology of the cactus Coryphantha elephantidens in the tropical dry forest of Central Mexico

AbstractFloral traits and sexual systems in angiosperms are strategies that enhance outcrossing within hermaphrodite flowers and among individuals in a population. Sexual systems with unisexual flowers have also evolved among angiosperms, resulting in sex specialization. Furthermore, the interaction of floral traits and floral visitors determines successful plant reproduction. Globose cacti are bee pollinated, and variation in the diversity of their pollinator assemblages is strongly associated with floral phenotype. Our objective was to describe the floral biology of the cactus Coryphantha elephantidens and to determine its relationship with pollinators. Floral traits were studied by direct observations in live and fixed flowers. The breeding system was determined using two estimators based on floral morphology: pollen grains to ovules per flower (P/O) ratio and outcrossing index. Pollination treatments were conducted to determine the mating system. Floral visitors were recorded using direct observation. Flowers of C. elephantidens are variable in color, protandric, herkogamous and nectarless. Estimators of the breeding system indicated xenogamy, which is consistent with the obligate outcrossing revealed by the pollination experiment. Thirty‐seven percent of the plants have female flowers that do not produce pollen, making this population functionally gynodioecious. Both fruit and seed set were high compared to other globose cacti. Pollinators included eight species of native bees, a more diverse pollinator assemblage than other globose cacti. Given the high pressure on pollen due to functional gynodioecy, nectarless flowers, an outcrossing mating system, and the necessity of pollinators to set seeds, we concluded that native bees are highly efficient pollinators that play a crucial role in the sexual reproduction of C. elephantidens.

Decline of six native mason bee species following the arrival of an exotic congener

A potential driver of pollinator declines that has been hypothesized but seldom documented is the introduction of exotic pollinator species. International trade often involves movement of many insect pollinators, especially bees, beyond their natural range. For agricultural purposes or by inadvertent cargo shipment, bee species successfully establishing in new ranges could compete with native bees for food and nesting resources. In the Mid-Atlantic United States, two Asian species of mason bee (Osmia taurus and O. cornifrons) have become recently established. Using pan-trap records from the Mid-Atlantic US, we examined catch abundance of two exotic and six native Osmia species over the span of fifteen years (2003–2017) to estimate abundance changes. All native species showed substantial annual declines, resulting in cumulative catch losses ranging 76–91% since 2003. Exotic species fared much better, with O. cornifrons stable and O. taurus increasing by 800% since 2003. We characterize the areas of niche overlap that may lead to competition between native and exotic species of Osmia, and we discuss how disease spillover and enemy release in this system may result in the patterns we document.

Forest fragments influence pollination and yield of soybean crops in Chaco landscapes

Habitat remnants act as a source of pollinators potentially relevant for crop pollination and yield. This work analyzes how habitat loss influences pollinators, effective pollination and yield of soybean crops. The study area comprises ten sites adjacent to forest patches surrounded by a soybean matrix in central Argentina (eight sites in the season 2014–2015 and two sites in the season 2015–2016). Pollination was estimated by pollen deposition and frequency of flower visitors. Pollen deposition on stigmas and seed set were measured comparing open plants and plants with pollinator exclusion. These response variables were compared considering increasing distance to the forest edge and an increasing gradient of forest patch size. Bees were the most frequent visitors of soybean flowers, especially honeybees, but also at least three native bee species were recorded. Open plants showed higher rates of stigmatic pollen deposition than plants with pollinator exclusion, but seed set was similar. Total insect visitation rates, especially of native insects, decreased with distance to the forest edge and so did pollen deposition. Pollen deposition and seed set increased with increasing forest patch size for plants located near and far from the forest edge, respectively. Overall, our results suggest that the contribution of native pollinators from local forest patches is important for effective pollination across the landscape. Small patches of forest (approximately 1 ha.) guarantee pollinators to ensure plant yields similar to the yields of plants growing close to large patches, but only at short distances; while larger forest patches provide better pollination services for the crop at larger distances from the forest edge. However, we encourage further studies because results suggest that other factors may also influence soybean pollination and production.

Diversity of Bee Assemblage (Family Apidae) in Natural and Agriculturally Intensified Ecosystems in Uruguay.

Bees (Family Apidae) hold a key role as pollinators in a wide range of angiosperm communities. South America suffered strong modifications during the last decade due to increasing anthropic activities and the expansion of agricultural areas, particularly the boom of soybean. The goal of this research was to know the current diversity of bees in South and Low Littoral regions in Uruguay. Specimens were collected in the seasons 2015-2016 and 2016-2017 on natural meadows, cultivated grasslands, soybean fields, among others flowering communities. Collected specimens were classified following taxonomic keys. Forty-five bee species or taxa were distinguished belonging to the subfamilies Megachilinae (11), Apinae (22), Halictinae (7), Colletinae (2), and Andreninae (3). Most taxa were classified up to genus and 14 to species level. Bee diversity was higher for the South region, with traditional agriculture and rangelands, than that of the Low Littoral region where an increasing agricultural land use took place during the last decade, particularly soybean. In addition, this research aimed to study the presence of native bees and the introduced Apis mellifera (Apinae) in a soybean field at four transects located at 0, 50, 100, and 200 m from the crop border in both seasons. Native bee species were only present at 0 and 50 m, pointing to the relevance of natural edge plant communities for their preservation. This is the first survey on native bee diversity in Uruguay to be regarded as a baseline and the setup of conservation strategies.

Effects of the Neonicotinoid Imidacloprid on the Feeding Behavior of Melipona quadrifasciata anthidioides Lep.

Even though meliponines are among the greatest pollinating agents in Neotropical ecosystems, the populations of these bees are in decline due to anthropic actions, such as the indiscriminate use of pesticides. Neonicotinoids, such as Imidacloprid, are used in many crops and have been shown to be one of the pesticides groups with the most damaging effects on the health of bee colonies. The goals of this work were (1) to evaluate the ability of Melipona quadrifasciata, a native Brazilian stingless bee species, to detect the presence of Imidacloprid in artificial diets, and (2) to evaluate how this insecticide may affect their behavior. For this purpose, behavioral experiments were carried out in observation arenas where artificial flowers containing different concentrations of Imidacloprid (0%, 1%, 5%, 10%, and 20%) were made available to forager bees and their choice and behavior were registered. Our results showed that bee choices were not affected by the different concentrations of Imidacloprid, even at extremely high doses in the flowers (20%). It was also found that the presence of this insecticide interfered with the communication between individuals as a result of reduced antennation events. Both findings, the apparent inability of bees to detect the presence of the insecticide and the change in behavior caused by the exposition to the volatilized product, may rapidly lead to colony losses in nature.

Conocimiento de las abejas nativas sin aguijón y cambio generacional entre los mayas lacandones de Nahá, Chiapas

The Lacandon Maya were settled in the Lacandon forest since the 17th century; their experience and knowledge allow them to know and manage different natural elements, like the Native Stingless Bees (nsb). The present research registered the species of nsb and the differentiated knowledge about them in Nahá, Chiapas. From 2015 to 2018, through work with key collaborators and entomological collections, the species of NSB identified by the local population of the Flora and Fauna Protection Area of Nahá (ffpan) were determined. Later a questionnaire was applied to 68 heads of family, all males, to estimate the level of knowledge they have and the uses they give to the native stingless bees, according to age ranges. A total of 15 species of native bees were registered, of which honey is obtained mainly from four: Tetragonisca angustula (Ajyus), Scaura argyrea (K’amas kap’), Plebeia frontalis (Ak chip kap) y Melipona solani (Jach K’ojo’). We registered a differentiated knowledge of the heads of family in Nahá about the 15 species of nsb based on their behavior, morphology and the places where they live. The general tendency is the loss of knowledge, and it is accentuated among the young people. The causes are related to the weakening of the transmission’s mechanisms of knowledge, the decrease of the recollection activities and the absence of management of colonies in their homegardens, as well as the arrival of products that substitute honey and wax, offered at lower prices.

Beyond neonicotinoids – Wild pollinators are exposed to a range of pesticides while foraging in agroecosystems

Pesticide exposure is a growing global concern for pollinator conservation. While most current pesticide studies have specifically focused on the impacts of neonicotinoid insecticides toward honeybees and some native bee species, wild pollinators may be exposed to a broader range of agrochemicals. In 2016 and 2017 we collected a total of 637 wild bees and butterflies from the margins of cultivated agricultural fields situated on five Conservation Areas in mid-northern Missouri. Pollinators were composited by individual genera (90 samples) and whole tissues were then analyzed for the presence of 168 pesticides and degradation products. At least one pesticide was detected (% frequency) in the following wild bee genera: Bombus (96%), Eucera (75%), Melissodes (73%), Ptilothrix (50%), Xylocopa (50%), and Megachile (17%). Similarly, at least one pesticide was detected in the following lepidopteran genera: Hemaris (100%), Hylephila (75%), Danaus (60%), and Colias (50%). Active ingredients detected in >2% of overall pollinator samples were as follows: metolachlor (24%), tebuconazole (22%), atrazine (18%), imidacloprid desnitro (13%), bifenthrin (9%), flumetralin (9%), p, p′-DDD (6%), tebupirimfos (4%), fludioxonil (4%), flutriafol (3%), cyproconazole (2%), and oxadiazon (2%). Concentrations of individual pesticides ranged from 2 to 174 ng/g. Results of this pilot field study indicate that wild pollinators are exposed to and are potentially bioaccumulating a wide variety of pesticides in addition to neonicotinoids. Here, we provide evidence that wild bee and butterfly genera may face exposure to a wide range of insecticides, fungicides, and herbicides despite being collected from areas managed for conservation. Therefore, even with the presence of extensive habitat, minimal agricultural activity on Conservation Areas may expose pollinators to a range of pesticides.

Native bee communities vary across three prairie ecoregions due to land use, climate, sampling method and bee life history traits

Abstract Recent evidence indicates that many native bee species are in decline due to the cumulative effects of multiple human‐induced stressors such as habitat loss, pesticide exposure, pathogens, and climate change. These declines have raised interest in the status of native bees and in developing tools that support management of bee communities and the ecosystem services they deliver. Native bees were surveyed using pan traps and netting over 2 years at 68 locations in croplands and rangelands across three ecological regions of Alberta's prairies – the Grassland, Parkland, and Boreal Natural Regions – to evaluate patterns in bee communities in response to disturbance and ecological gradients. Bee community composition was different across land use and ecoregions. While several cavity‐nesting species had a strong association with rangelands, cavity‐nesting bees tended to be less common in croplands and may be more sensitive to loss of rangeland habitat. Response patterns in overall bee abundance and richness were driven by interactions between region and land use, highlighting the need for regional studies to understand how bee communities respond to these factors. This survey is one of the first to sample the response of bee communities to landscape disturbance across a broad spatial area of the Canadian prairies. Large‐scale compositional studies are essential for understanding the status of native bee communities, and for monitoring long‐term trends over time. We recommend subsequent coordinated surveys using standardised methods across broad spatial scales.

Avocado crops as a floral resource for native bees of Chile

BackgroundChile is the second largest avocado producer in the world. However, there have been few studies on interactions between native bees and avocado pollination in a Chilean environment. The flowering period of avocado is very sensitive to temperature fluctuations and so environmental conditions, particularly cool temperatures, can have a strong influence on its floral behaviour. Thus, we aimed to determine whether temperature also influences bee visitation rates to avocado flowers or if this was due to the number of available flowers. Moreover, we proposed to verify the attractiveness of avocado flowers to native bees and compare flower handling time and type of floral resource collected between managed and native bees.MethodsAn avocado orchard of “Hass” cultivar located in the Mediterranean region of Chile was studied during the flowering season of 2016. The frequency of exotic and native bee species in flowers, floral phenology, and environmental temperature were analysed, and the foraging behaviours of exotic and native bee species in avocado flowers compared.ResultsFive Chilean native and two exotic species were recorded visiting avocado flowers at the studied orchard. The bees generally sought nectar rather than pollen. The European honeybee (Apis mellifera) was the most frequent flower visitor, followed by the native species Colletes cyanescens and Cadeguala occidentalis. There was a strong positive correlation between temperature and number of visits, but no significant correlation between number of open flowers and number of visits.ConclusionsNative Chilean bees visited avocado flowers and some of them were frequent floral visitors. They generally sought for nectar rather than pollen and were as fast as honeybees handling avocado flowers. The environmental temperature plays a key role in the frequency of bees in avocado flowers. The warmer weather is related to the higher number of bees visits to avocado flowers.

What is the most suitable native bee species from the Neotropical region to be proposed as model-organism for toxicity tests during the larval phase?

Currently, Brazil has a full framework for pesticide risk assessment established for Apis mellifera, based on the North American approach. However, the use of Apis mellifera as model-organism as a surrogate for Brazilian native species of stingless bees has been questioned. Assessments on other stages of development than adult individual are essential. Our study aimed to standardize in vitro larval rearing method for the stingless bee species Scaptotrigona postica and Tetragonisca angustula, comparing the results to those obtained for M. scutellaris (previously described), for proposing the most suitable one for using in toxicological larval tests. We used the most efficient method for determining the toxicity of dimethoate on S. postica larvae. We presented the first comparative approach of responses to in vitro larval rearing methods among native bee species from Neotropical region, for use in risk assessment. Our results showed that S. postica was the most suitable native species to be proposed as model-organism. In addition, our results are also very useful for a ring test to validate the method, in accordance to OECD.

Bee hotels host a high abundance of exotic bees in an urban context

Bee hotels are increasingly set up by land managers in public parks to promote wild bee populations. However, we have very little evidence of the usefulness of bee hotels as tools to help the conservation of wild bees within cities. In this study, we installed 96 bee hotels in public parks of Marseille (France) for a year and followed their use as a nesting substrate by the local fauna. The most abundant species that emerged from bee hotels was the exotic bee species Megachile sculpturalis, representing 40% of all individuals. Moreover, we only detected four native bee species all belonging to the Osmia genus. More worryingly, we found a negative correlation between the occurrence of M. sculpturalis in bee hotels and the presence of native bees. One hypothesis to explain this result might be linked to the described territorial and aggressive behaviour of M. sculpturalis toward the nests built by the native fauna. This study raises the question about the usefulness of bee hotels for the conservation of native bees especially within cities harbouring high abundance of exotic bees. We provide here concrete advices to land managers to build bee hotels that can both host native bees and prevent the installation of M. sculpturalis.

Assessment of Genetic Variation in Apis nigrocincta (Hymenoptera: Apidae) in Sulawesi Revealed by Partial Mitochondrial Cytochrome Oxidase I Gene Sequences.

Asian cavity-nesting honey bee Apis nigrocincta, a native bee species from Sulawesi and the Philippines, plays a vital role in pollinating flowering plants in local ecosystem and agriculture. In this study, we assessed the intraspecific genetic variation of A. nigrocincta using the sequence of cytochrome c oxidase subunit I (COI). Molecular phylogenetic analysis showed that there were three main clades in A. nigrocincta specimens from Sulawesi based on their respective locations (North, Central, and South Sulawesi). Genetic distance analysis using the Kimura 2-parameter (K2P) model showed that the intraspecific genetic distance in Sulawesi specimens ranged from 0.000 to 0.055. There are 26 nucleotide polymorphic sites within Sulawesi A. nigrocincta. The variation was dominated by transition T ↔ C. The molecular identification result was supported by morphological identification. The results of the two methods agree that the specimen under study was A. nigrocincta. The result of genetic distance calculation indicated that although the tested specimens were derived from remote locations, the genetic variation was still within the range of intraspecific variation.

Citizen science improves our understanding of the impact of soil management on wild pollinator abundance in agroecosystems

Native bees provide essential pollination services in both natural and managed ecosystems. However, declines in native bee species highlight the need for increased understanding of land management methods that can promote healthy, persistent populations and diverse communities. This can be challenging and costly using traditional scientific methods, but citizen science can overcome many limitations. In this study, we examined the distribution and abundance of an agriculturally important wild bee species, the squash bee (Eucera (Peponapis) pruinosa, Hymenoptera: Apidae). They are ground nesting, specialist bees that depend on cultivated varieties of Cucurbita (squash, pumpkins, gourds). The intimate relationship between squash bees and their host plants suggests that they are likely sensitive to farm management practices, particularly those that disturb the soil. In this study, citizen scientists across Michigan used a survey to submit field management and bee observation data. Survey results indicated that squash bees occupy a wide geographic range and are more abundant in farms with reduced soil disturbance. Citizen science provided an inexpensive and effective method for examining impacts of farm management practices on squash bees and could be a valuable tool for monitoring and conserving other native pollinators.

Propolis of Trigona spp. Protects Mucosa from Aspirin-Induced Gastric Mucosal Damage in Rats

Background : Helicobacter pylori and non-steroid anti-inflammatory drugs are the major causes of peptic ulcer in the world. Indonesian native stingless bee species, Trigona spp. , produces propolis that might be effective to protect mucosal damage. The aim of the study was to determine the protective effect of Trigona spp. propolis on aspirin-induced gastric mucosal damage in rats. Methods : This experimental study was conducted from September–November 2013 at Animal Laboratory of Department of Pharmacology and Therapy Faculty of Medicine Universitas Padjadjaran. Healthy male Wistar rats (n=24) aged 2–3 months old and weighed 200–250 grams were randomly divided into three groups. The first group was control negative, the second group was given 100 mg/kg body weight of aspirin, and the third group was given 200 mg/kg body weight of Trigona spp . propolis, one hour before administration of 100 mg/kg body weight of aspirin. After two weeks of treatment, rats were sacrificed by laparotomy to obtain gastric tissues, followed by processing for the paraffin section for histopathological analysis. The grade of gastric mucosal damage was determined under a light microscope. Data were then compared between groups using the Mann-Whitney test. Results : Oral administration of aspirin-induced gastric mucosal damage ranging from grade 0 to grade IV; whereas administration of propolis showed a reduction of gastric mucosal damage’s grade when compared to the aspirin group (p<0.05). Conclusions : Trigona spp. propolis has a protective effect on aspirin-induced gastric mucosal damage. Further study is encouraged to study an optimal dose of aspirin after propolis administration.

Stingless Bees (Melipona subnitida) Overcome Severe Drought Events in the Brazilian Tropical Dry Forest by Opting for High-Profit Food Sources.

In the Brazilian Tropical Dry Forest, the Caatinga, stingless bees (Apidae, Meliponini) need to adjust their foraging behavior to a very short and unpredictable blooming period. Melipona subnitida Ducke 1910 is one of the few meliponine species adapted to the environmental peculiarities of this biome. To get an insight into how these highly eusocial bees are able to maintain their perennial colonies despite extended periods of food scarcity, we asked the following questions: (1) At which plant species do colonies of M. subnitida collect their food during the rainy season? And (2) are there any plant species during the dry season, from which the colonies may profit for replenishing their food stores? During 1year, we collected monthly honey and pollen samples from recently built storage pots of five colonies of M. subnitida and identified the botanical origin of the collected resources. In the course of our study, the colonies foraged at native trees, shrubs, and herbaceous species, demonstrating the importance of all plant strata for the bees' diet. Profitable plants, which bloom mainly during the rainy season and usually produce a great number of flowers, were frequently sampled in new pots throughout the entire study, even during the dry season. From our results, we compiled a list of the most important plant species providing floral resources for bees throughout the year, including periods of drought. We recommend these plants for restoration areas to improve the conservation of native bee species and local beekeeping in the Brazilian Tropical Dry Forest.

Trap nest preference of solitary bees in fragments of the Baturité massif, Atlantic Forest, Brazil.

The study investigated native solitary bee species that nest in pre-existing cavities in the Baturité Massif, State of Ceará, Brazil, their preference for nest substrates and aspects of these bee communities. Samples were taken in four distinct areas of the Baturité Massif using three types of trap-nests: dried bamboo internodes, cardboard tubes and rational boxes. Out of the 185 nests offered, 34 were colonized and 24 of them produced 131 bees, belonging to two families (Apidae and Megachilidae) and five genera (Centris, Mesocheira, Euglossa, Megachile and Coelioxys) from six species, including parasitic ones. Nesting preference was observed to certain types of substrates (χ²=17.89, p<0.001), with bamboo internodes being preferred by bee to build their nests, while monthly variation in temperature and humidity did not affect bee emergency. Spite of few nests foundations and the few species sampled, this work contributed to an unprecedented knowledge about the species that use pre-existing cavities in the Baturité Massif that may contribute to assist in the maintenance and conservation of this mountainous area and can be useful for pollination services of native and agricultural plants.

Attracting Native Bees to Your Florida Landscape

Florida is home to approximately 315 species of native wild bees. These bees rely on flowers for survival; their diets consist exclusively of pollen and nectar harvested from flowers. Recently reported declines in some bee species have heightened awareness of bee conservation across the United States and motivated efforts to increase floral resources for bees. This 7-page fact sheet written by Rachel E. Mallinger, Wayne Hobbs, Anne Yasalonis, and Gary Knox and published by the UF/IFAS Entomology and Nematology Department shows how gardeners and land managers can aid in conservation efforts by planting flowers for bees in home or community gardens. http://edis.ifas.ufl.edu/IN1255