The Dependence of Crops for Pollinators and the Economic Value of Pollination in Brazil

Intake of imidacloprid in lethal and sublethal doses alters gene expression in Apis mellifera bees

Bees are important pollinators for ecosystems and agriculture; however, populations have suffered a decline that may be associated with several factors, including habitat loss, climate change, increased vulnerability to diseases and parasites and use of pesticides. The extensive use of neonicotinoids, including imidacloprid, as agricultural pesticides, leads to their persistence in the environment and accumulation in bees, pollen, nectar, and honey, thereby inducing deleterious effects. Forager honey bees face significant exposure to pesticide residues while searching for resources outside the hive, particularly systemic pesticides like imidacloprid. In this study, 360 Apis mellifera bees, twenty-one days old (supposed to be in the forager phase) previously marked were fed syrup (honey and water, 1:1 m/v) containing a lethal dose (0.081 μg/bee) or sublethal dose (0.00081 μg/bee) of imidacloprid. The syrup was provided in plastic troughs, with 250 μL added per trough onto each plastic Petri dish containing 5 bees (50 μL per bee). The bees were kept in the plastic Petri dishes inside an incubator, and after 1 and 4 h of ingestion, the bees were euthanised and stored in an ultra-freezer (-80 °C) for transcriptome analysis. Following the 1-h ingestion of imidacloprid, 1516 genes (73 from lethal dose; 1509 from sublethal dose) showed differential expression compared to the control, while after 4 h, 758 genes (733 from lethal dose; 25 from sublethal) exhibited differential expression compared to the control. All differentially expressed genes found in the brain tissue transcripts of forager bees were categorised based on gene ontology into functional groups encompassing biological processes, molecular functions, and cellular components. These analyses revealed that sublethal doses might be capable of altering more genes than lethal doses, potentially associated with a phenomenon known as insecticide-induced hormesis. Alterations in genes related to areas such as the immune system, nutritional metabolism, detoxification system, circadian rhythm, odour detection, foraging activity, and memory in bees were present after exposure to the pesticide. These findings underscore the detrimental effects of both lethal and sublethal doses of imidacloprid, thereby providing valuable insights for establishing public policies regarding the use of neonicotinoids, which are directly implicated in the compromised health of Apis mellifera bees.

Flower-bee versus pollen-bee metanetworks in fragmented landscapes

Understanding the organization of mutualistic networks at multiple spatial scales is key to ensure biological conservation and functionality in human-modified ecosystems. Yet, how changing habitat and landscape features affect pollen-bee interaction networks is still poorly understood. Here, we analysed how bee-flower visitation and bee-pollen-transport interactions respond to habitat fragmentation at the local network and regional metanetwork scales, combining data from 29 fragments of calcareous grasslands, an endangered biodiversity hotspot in central Europe. We found that only 37% of the total unique pairwise species interactions occurred in both pollen-transport and flower visitation networks, whereas 28% and 35% were exclusive to pollen-transport and flower visitation networks, respectively. At local level, network specialization was higher in pollen-transport networks, and was negatively related to the diversity of land cover types in both network types. At metanetwork level, pollen transport data revealed that the proportion of single-fragment interactions increased with landscape diversity. Our results show that the specialization of calcareous grasslands' plant-pollinator networks decreases with landscape diversity, but network specialization is underestimated when only based on flower visitation information. Pollen transport data, more than flower visitation, and multi-scale analyses of metanetworks are fundamental for understanding plant-pollinator interactions in human-dominated landscapes.

Revamped mini-αA-crystallin showed improved skin permeation and therapeutic activity against melittin-induced toxicity

Melittin is honey bee venom's primary and most toxic pharmacologically active component. Melittin causes haemolysis, lymphocyte lysis, long-term pain, localised inflammation followed by rhabdomyolysis, and severe renal failure. Renal failure or cardiovascular complications could lead to the victim's death. Severe honey bee bites are treated with general medication involving antihistaminic, anti-inflammatory, and analgesic drugs, as a specific treatment option is unavailable. An earlier study showed the anti-hemolysis and anti-lymphocyte lysis activity of mini- αA-crystallin (MAC), a peptide derived from human eye lens alpha-crystallin. MAC's use has often been restricted despite its high therapeutic potential due to its poor skin permeability. This study compared the skin permeation, anti-inflammatory and analgesic activities of natural peptide MAC and its modified version (MAC-GRD) formed by attaching cell-penetrating peptide (CPP) and GRD amino residues into MAC. Gel formulations were prepared for MAC and MAC-GRD peptides using carbopol (1% w/w), Tween 80 (1%), and ethanol (10%). An ex-vivo skin permeation study was performed using a vertical-type Franz diffusion apparatus. Preclinical in-vivo experiments were conducted to compare the native and modified peptide formulations against melittin-induced toxicity in Wistar rats. MAC gel, MAC-GRD gel and 1% hydrocortisone cream significantly reduced the melittin-induced writhing (20.16 ± 0.792) response in rats with 15.16 ± 0.47, 11.16 ± 0.477 and 12.66 ± 0.66 wriths, respectively. There was a significant reduction in melittin-induced inflammation when MAC-GRD gel was applied immediately after melittin administration. At 0.5, 1, 3, and 5 h, the MAC-GRD-treated rat paws were 0.9 ± 0.043 mm, 0.750 ± 0.037 mm, 0.167 ± 0.0070 mm, and 0.133 ± 0.031 mm thick. Administration of melittin resulted in reduced GSH (antioxidant) levels (47.33 ± 0.760 μg/mg). However, treatment with MAC-GRD gel (71.167 ± 0.601 μg/mg), MAC gel (65.167 ± 1.138 μg/mg), and 1% hydrocortisone (68.33 ± 0.667 μg/mg) significantly increased the antioxidant enzyme levels. MAC-GRD gel significantly reduced the elevated MDA levels (6.933 ± 0.049 nmol/mg) compared to the melittin group (12.533 ± 0.126 nmol/mg), followed by the 1% hydrocortisone (7.367 ± 0.049 nmol/mg) and MAC gel (7.917 ± 0.048 nmol/mg). MAC-GRD demonstrated more skin permeability and superior anti-inflammatory, analgesic, and antioxidant activities when compared to MAC gel. When compared to standard 1% hydrocortisone cream, MAC-GRD had better anti-inflammatory, analgesic, antioxidant, and comparable action in anti-oxidant restoration against melittin. These findings suggest that the developed MAC-GRD gel formulation could help to treat severe cases of honey bee stings.

Food plants in Brazil: origin, economic value of pollination and pollinator shortage risk

Pollination is a key ecosystem service of critical importance for food production. However, globally, several regions are already experiencing pollinator shortage as pollinators are declining. Here, we investigate the origin, pollinator dependence and economic value of 199 food crops cultivated in Brazil to understand to which extent (1) Brazilian agriculture is vulnerable to pollinator shortage, and (2) Brazilian society has already achieved a comprehensive perspective about crop dependence. We used Brazil as a case study as it is a megadiverse tropical country and the 3rd largest world crop producer and exporter, with most of the crops depending on pollinators. Our findings revealed that over half (53.7%) of the food crops in Brazil are native, with the North region of Brazil housing the higher diversity of native crops, in contrast with the South and Southeast regions. Additionally, considering the reproductive systems, among native food crops, 65.6% exhibit self-incompatibility or dioecy (i.e., requiring obligatory cross-pollination), whereas 30.6% of exotic food crops display this trait. Overall, Brazilian municipalities produce more exotic crops than native ones, with almost 4/5 of the total agricultural area of the country dedicated to the cultivation of exotic crops, which are generally self-compatible commodities that rely low to modestly on pollinators. Regarding the biomes, we observe that this pattern is followed by most of them, but for the Caatinga dry forest, where native crops dependent on pollinators predominate. However, when soybean is removed from the analysis, the areas devoted to exotic crops always decreased, even being equal to native crops in the Atlantic forest. Our results also indicate that considering the pollinator shortage, some Brazilian biomes may be at risk of losing >20% of their yields, mainly in the Caatinga dry forest and the Atlantic forest. Therefore, in this paper, we are discussing that the expansion of monocultures in Brazil's agricultural lands may have several impacts on the provision of pollination services, food production and, then, on food security not only for the Brazilian population, as Brazil is the 3rd largest world agricultural producer and exporter.

Like an "espresso" but not like a "cappuccino": landscape metrics are useful for predicting coffee production at the farm level but not at the municipality level

Coffee farms receive ecosystem services that rely on pollinators and pest predators. Landscape-scale processes regulate the flow of these biodiversity-based services. Consequently, the coffee farms' surrounding landscape impacts coffee production. This paper investigates how landscape structure can influence coffee production at different scales. We also evaluated the predictive utility of landscape metrics in a spatial (farm level) and aspatial approach (municipality level). We tested the effect of landscape structure on coffee production for 25 farms and 30 municipalities in southern Brazil. We used seven landscape metrics at landscape and class levels to measure the effect of landscape structure. At the farm level, we calculated metrics in five buffers from 1 to 5 km from the farm centroid to measure their scale of effect. We conducted a model selection using the generalized linear model (GLM) with a Gamma error distribution and inverse link function to evaluate the impact of landscape metrics on coffee production in both spatial and aspatial approaches. The landscape intensity index had a negative effect on coffee production (AICc = 375.59, p < 0.001). The native forest patch density (AICc = 390.14, p = 0.011) and landscape diversity (AICc = 391.18, p = 0.023) had a positive effect on production. All significant factors had effects at the farm level in the 2 km buffer but no effects at the municipality level. Our findings suggest that the landscape composition in the immediate surroundings of coffee farms helps predict production in a spatially explicit approach. However, these metrics cannot detect the impact of the landscape when analyzed in an aspatial approach. These findings highlight the importance of the landscape spatial structure, mainly the natural one, in the stability of coffee production. This study enhanced the knowledge of coffee production dependence on landscape-level processes. This advance can help to improve the sustainability of land use and better planning of agriculture, ensuring food and economic safety. Furthermore, our framework provides a method that can be useful to scrutinize any cropping system with census data that is either spatialized or not.

Temporal dynamics of Apis mellifera (Hymenoptera: Apidae) during flowering in indeterminate soybean (Glycine max)

Soybean varieties with indeterminate growth habit are widely used in the state of Mato Grosso do Sul and are characterized by not having well-defined phenological stages. Due to the importance of bee conservation, studies on the frequency and time of visitation in indeterminate soybean are needed. Samples were collected in a 4-ha plot of soybeans not treated with insecticides. Sampling was carried out at random spots, throughout the flowering period, starting at 08h:00min, during 15 min/hour, successively until 16h:00min. Generalized Linear Models were generated and the Poisson regression model provided the best fit, reflecting the significant differences revealed by the deviance analysis. The association between bees and climatic variables was tested with the Spearman's correlation. The temporal pattern of bee visitation was independently influenced by flowering period and time of day. However climatic variables did not influence significantly bee visitation rate. In the first days of flowering, bees were more abundant, especially between 10h and 15h. These results have practical implications in the maintenance of this species during soybean management practices, contributing to a balanced coexistence between beekeepers and soybean growers, by avoiding applications of phytosanitary products during the periods of high bee visitation.

Insect pollinators can unlock an annual monetary value of more than US $100 million from crop production in Rwanda

Insect pollinators provide a natural ecosystem service to more than 80% of known flowering plants, many of which are part of our diet. However, their importance in Africa and an agriculture-dependent country like Rwanda has yet to receive attention. This encumbers policy formulation and investments in insect pollinators as a strategic agronomic input. Meanwhile, Rwanda cultivates crops that can benefit significantly from insect pollinators for superior agronomic outputs. To uncover this, we characterized the dependence of the crop production subsector on insect pollinators. Using the bioeconomic approach, we assessed the total economic value and the value due to insect pollinators of crops cultivated in Rwanda. We also evaluated the crop's production value per ton and whether production would meet consumption demands in the complete absence of insect pollinators. Using 71 representative crops currently grown in Rwanda, we found a direct dependency of 62% on insect pollinators. Of 32 representative crops used for economic valuation in two years (2014 and 2020), their total monetary value is estimated at $2.551 billion to $2.788 billion. Direct insect pollinator-dependent crops accounted for 20% (2014) to 18% (2020) of this value, with the share attributed to insect pollinators above $100 million. The sector's vulnerability to insect pollinators decreased from 7.3% in 2014 to 4.3% in 2020. The mean production value per ton of the direct insect pollinator-dependent crops was found to be higher in 2014 before declining in 2020. Using 21 representative crops from 2014 to 2020, we found that many direct insect pollinator-dependent crops will struggle to meet consumption demands in the complete absence of all suitable insect pollinators. Finally, we propose interventions and future research that could be undertaken. These insights are a critical first step to propel the government to act on insect pollination to support its food security agenda.

Effects of Plant-Based Supplement on Oxidative Stress of Honey Bees (Apis mellifera) Infected with Nosema ceranae

One of the most important approaches in the prevention and treatment of nosemosis is the use of herbal preparations as food supplements for bees. Therefore, the aim of this study was to investigate the effects of a plant-based supplement branded as "B+" on honeybees in a laboratory experiment. Four experimental groups were established: treated group (T), N. ceranae-infected and treated group (IT), N. ceranae-infected group (I) and non-infected group (NI). Survival, N. ceranae spore load and oxidative stress parameters together with expression levels of antioxidant enzyme genes and vitellogenin gene were monitored. The mortality in the T, IT and NI groups was significantly (p < 0.001) lower than in than in the I group. Within Nosema-infected groups, the IT group had a significantly lower (p < 0.001) number of N. ceranae spores than the I group. In addition, expression levels of genes for antioxidant enzymes were lower (p < 0.001) in the IT group compared to the I group. The concentration of malondialdehyde and the activities of antioxidant enzymes (superoxide dismutase, catalase and glutathione S-transferase) were significantly lower (p < 0.001) in the IT group compared to the I group. No negative effects of the tested supplement were observed. All these findings indicate that the tested supplement exerted beneficial effects manifested in better bee survival, reduced N. ceranae spore number and reduced oxidative stress of bees (lower expression of genes for antioxidant enzymes and oxidative stress parameters).

Imidacloprid: Impact on Africanized Apis mellifera L. (Hymenoptera: Apidae) workers and honey contamination

Apis mellifera L. (Hymenoptera: Apidae) is fundamental in the production chain, ensuring food diversity through the ecosystem service of pollination. The aim of this work was to evaluate the impact of imidacloprid, orally, topically, and by contact, on A. mellifera workers and to verify the presence of this active ingredient in honey. Toxicity levels were verified by bioassays. In bioassay 1, the levels correspond to the percentages of 100, 10, 1, 0.1, and 0.01% of the recommended concentration for field application of the commercial product Nortox® (active ingredient imidacloprid), with which we obtained the mean lethal concentration (LC50) in 48 h for A. mellifera, determining the concentration ranges to be used in the subsequent bioassays. Bioassays 2 and 3 followed the guidelines of the Organization for Economic Cooperation and Development, which specify the LC50 (48 h). In bioassay 4, the LC50 (48 h) and the survival rate of bees for a period of 120 h were determined by contact with a surface contaminated with imidacloprid, and in bioassay 5, the interference of the insecticide with the flight behavior of bees was evaluated. Honey samples were collected in agroecological and conventional georeferenced apiaries and traces of the imidacloprid were detected by means of high-performance liquid chromatography (HPLC-UV) with extraction by SPE C18. Bee survival was directly affected by the concentration and exposure time, as well behavioral performance, demonstrating the residual effect of imidacloprid on A. mellifera workers. Honey samples from a conventional apiary showed detection above the maximum residue limits (MRL) allowed by the European Union (0.05 μg mL-1), but samples from other apiaries showed no traces of this insecticide. Imidacloprid affects the survival rate and behavior of Africanized A. mellifera and honey quality.

Integrating public engagement to intensify pollination services through ecological restoration

Globally, human activities impose threats to nature and the provision of ecosystem services, such as pollination. In this context, ecological restoration provides opportunities to create managed landscapes that maximize biodiversity conservation and sustainable agriculture, e.g., via provision of pollination services. Managing pollination services and restoration opportunities requires the engagement of distinct stakeholders embedded in diverse social institutions. Nevertheless, frameworks toward sustainable agriculture often overlook how stakeholders interact and access power in social arenas. We present a perspective integrating pollination services, ecological restoration, and public engagement for biodiversity conservation and agricultural production. We highlight the importance of a comprehensive assessment of pollination services, restoration opportunities identification, and a public engagement strategy anchored in institutional analysis of the social arenas involved in restoration efforts. Our perspective can therefore guide the implementation of practices from local to country scales to enhance biodiversity conservation and sustainable agriculture.

Honey bees (Apis mellifera) modify plant-pollinator network structure, but do not alter wild species' interactions

Honey bees (Apis mellifera) are widely used for honey production and crop pollination, raising concern for wild pollinators, as honey bees may compete with wild pollinators for floral resources. The first sign of competition, before changes appear in wild pollinator abundance or diversity, may be changes to wild pollinator interactions with plants. Such changes for a community can be measured by looking at changes to metrics of resource use overlap in plant-pollinator interaction networks. Studies of honey bee effects on plant-pollinator networks have usually not distinguished whether honey bees alter wild pollinator interactions, or if they merely alter total network structure by adding their own interactions. To test this question, we experimentally introduced honey bees to a Canadian grassland and measured plant-pollinator interactions at varying distances from the introduced hives. We found that honey bees increased the network metrics of pollinator and plant functional complementarity and decreased interaction evenness. However, in networks constructed from just wild pollinator interactions, honey bee abundance did not affect any of the metrics calculated. Thus, all network structural changes to the full network (including honey bee interactions) were due only to honey bee-plant interactions, and not to honey bees causing changes in wild pollinator-plant interactions. Given widespread and increasing use of honey bees, it is important to establish whether they affect wild pollinator communities. Our results suggest that honey bees did not alter wild pollinator foraging patterns in this system, even in a year that was drier than the 20-year average.

Individual and social defenses in Apis mellifera: a playground to fight against synergistic stressor interactions

The honeybee is an important species for the agri-food and pharmaceutical industries through bee products and crop pollination services. However, honeybee health is a major concern, because beekeepers in many countries are experiencing significant colony losses. This phenomenon has been linked to the exposure of bees to multiple stresses in their environment. Indeed, several biotic and abiotic stressors interact with bees in a synergistic or antagonistic way. Synergistic stressors often act through a disruption of their defense systems (immune response or detoxification). Antagonistic interactions are most often caused by interactions between biotic stressors or disruptive activation of bee defenses. Honeybees have developed behavioral defense strategies and produce antimicrobial compounds to prevent exposure to various pathogens and chemicals. Expanding our knowledge about these processes could be used to develop strategies to shield bees from exposure. This review aims to describe current knowledge about the exposure of honeybees to multiple stresses and the defense mechanisms they have developed to protect themselves. The effect of multi-stress exposure is mainly due to a disruption of the immune response, detoxification, or an excessive defense response by the bee itself. In addition, bees have developed defenses against stressors, some behavioral, others involving the production of antimicrobials, or exploiting beneficial external factors.

Abamectin and difenoconazole monitoring in strawberry flowers and pollen sampled from Tetragonisca angustula (Latreille) (Hymenoptera: Apidae) hives located in crop vicinities

The increase in agricultural productivity associated with the emergence and the extensive use of pesticides is undeniable. However, strong evidence indicates that this continuous demand is causing serious environmental impacts and bringing toxic effects to associated biota as pollinating insects. The present work aims the determination of the insecticide abamectin (ABA) and the fungicide difenoconazole (DIF) in strawberry flowers (Fragaria x ananassa DUCH.) and pollen sampled from beehives of the stingless bee Tetragonisca angustula Latreille (Hymenoptera: Apidae) located nearby strawberry fields. For analysis, QuEChERS method was optimized, and the analytical performance of those two pesticides was verified. Then, the method was applied to strawberry flowers and the pollen was sampled during three field campaigns. While abamectin was not detected, the systemic fungicide difenoconazole was determined in almost all flowers and pollen samples, demonstrating the major persistence of this pesticide in investigated matrices. The results were then discussed about the difenoconazole application rate and transport to colonies to estimate a preliminary environmental risk assessment for stingless native bees. All calculations were proceeded considering exposure rates and toxicity data from the literature, adapted from Apis mellifera studies. In this sense, the determination, application, and discussion about risk assessment figure out as an important tool to the knowledge about the preliminary risks of native bees exposed to pesticides.

Non-optimal ambient temperatures aggravate insecticide toxicity and affect honey bees Apis mellifera L. gene regulation

In this study, we conducted a transcriptional analysis of five honey bee genes to examine their functional involvement vis-à-vis ambient temperatures and exposure to imidacloprid. In a 15-day cage experiment, three cohorts of one-day-old sister bees emerged in incubators, were distributed into cages, and maintained at three different temperatures (26 °C, 32 °C, 38 °C). Each cohort was fed a protein patty and three concentrations of imidacloprid-tainted sugar (0 ppb, 5 ppb and 20 ppb) ad libitum. Honey bee mortality, syrup and patty consumption were monitored daily over 15 days. Bees were sampled every three days for a total of five time points. RT-qPCR was used to longitudinally assess gene regulation of Vg, mrjp1, Rsod, AChE-2 and Trx-1 using RNA extracted from whole bee bodies. Kaplan-Meier models show that bees kept at both non-optimal temperatures (26 °C and 38 °C) were more susceptible to imidacloprid, with significantly higher mortality (P < 0.001 and P < 0.01, respectively) compared to the control. At 32 °C, no differences in mortality (P = 0.3) were recorded among treatments. In both imidacloprid treatment groups and the control, the expression of Vg and mrjp1 was significantly downregulated at 26 °C and 38 °C compared to the optimal temperature of 32 °C, indicating major influence of ambient temperature on the regulation of these genes. Within the ambient temperature groups, both imidacloprid treatments exclusively downregulated Vg and mrjp1 at 26 °C. AChE-2 and the poorly characterized Rsod gene were both consistently upregulated at the highest temperature (38 °C) compared to the ideal temperature (32 °C) in all treatment groups. Trx-1 showed no effect to both temperature and imidacloprid treatments and was regulated in an age-related manner. Overall, our results indicate that ambient temperatures amplify imidacloprid toxicity and affect honey bee gene regulation.

Floral Scents in Bee-Pollinated Buckwheat and Oilseed Rape under a Global Warming Scenario

Many wild plants and crops are pollinated by insects, which often use floral scents to locate their host plants. The production and emission of floral scents are temperature-dependent; however, little is known about how global warming affects scent emissions and the attraction of pollinators. We used a combination of chemical analytical and electrophysiological approaches to quantify the influence of a global warming scenario (+5 °C in this century) on the floral scent emissions of two important crop species, i.e., buckwheat (Fagopyrum esculentum) and oilseed rape (Brassica napus), and to test whether compounds that are potentially different between the treatments can be detected by their bee pollinators (Apis mellifera and Bombus terrestris). We found that only buckwheat was affected by increased temperatures. Independent of temperature, the scent of oilseed rape was dominated by p-anisaldehyde and linalool, with no differences in relative scent composition and the total amount of scent. Buckwheat emitted 2.4 ng of scent per flower and hour at optimal temperatures, dominated by 2- and 3-methylbutanoic acid (46%) and linalool (10%), and at warmer temperatures threefold less scent (0.7 ng/flower/hour), with increased contributions of 2- and 3-methylbutanoic acid (73%) to the total scent and linalool and other compounds being absent. The antennae of the pollinators responded to various buckwheat floral scent compounds, among them compounds that disappeared at increased temperatures or were affected in their (relative) amounts. Our results highlight that increased temperatures differentially affect floral scent emissions of crop plants and that, in buckwheat, the temperature-induced changes in floral scent emissions affect the olfactory perception of the flowers by bees. Future studies should test whether these differences in olfactory perception translate into different attractiveness of buckwheat flowers to bees.

Population Dynamics of Insect Pests and Beneficials on Different Snap Bean Cultivars

Snap bean is an important crop in the United States. Insecticides are commonly used against pests on snap bean, but many pests have developed resistance to the insecticides and beneficials are threatened by the insecticides. Therefore, host plant resistance is a sustainable alternative. Population dynamics of insect pests and beneficials were assessed on 24 snap bean cultivars every week for six weeks. The lowest number of sweetpotato whitefly (Bemisia tabaci) eggs was observed on cultivar 'Jade', and the fewest nymphs were found on cultivars 'Gold Mine', 'Golden Rod', 'Long Tendergreen', and 'Royal Burgundy'. The numbers of potato leafhopper (Empoasca fabae) and tarnished plant bug (Lygus lineolaris) adults were the lowest on cultivars 'Greencrop' and 'PV-857'. The highest numbers of adults were found in Week 1 (25 days following plant emergence) for B. tabaci and Mexican bean beetle (Epilachna varivestis); Week 3 for cucumber beetle, kudzu bug (Megacopta cribraria), and E. fabae; Weeks 3 and 4 for thrips; Week 4 for L. lineolaris; and Weeks 5 and 6 for bees. Temperature and relative humidity correlated with B. tabaci, E. varivestis, bee, and predator ladybird beetle populations. These results provide valuable information on the integrated pest management of snap beans.

Stingless bees: uses and management by meliponiculturist women in the Chaco region of Bolivia

BACKGROUND

Stingless bees have a great value as main pollinators of wild flowering and cultivated plants, thus playing a fundamental role in the maintenance of biodiversity and food security in Latin America. Despite their importance, stingless bees face numerous threats causing alarming population declines. Moreover, stingless bees have a great cultural and traditional value, since most products from the hive are used for a wide variety of purposes. A growing number of initiatives are encouraging the breeding of these bees, through training courses and modern management techniques. This study documents the knowledge on stingless bees and their products that meliponiculturists from the Chaco region of Bolivia have, as well as the influence that meliponiculture initiatives have on the management and general knowledge of the bees.

METHODS

Local richness and diversity of stingless bees was calculated using Hill numbers. Structured interviews were conducted with 59 meliponiculturists in order to characterize traditional and formal knowledge on stingless bees and meliponiculture. Generalized linear models were applied to assess the influence of training courses on the management of the bees. Also, a relative cultural importance index was calculated for each species.

RESULTS

Twelve Meliponini species were identified, and 15 local names were reported with morphological, defensiveness behavior, and nest description. There was no significant difference in the knowledge between different ethnical backgrounds or ages. A significant difference was observed in the use of supplementary feeding and assisted division, but none in the success in racking hives or in pest management, regarding the number or courses taken. The relative cultural importance index recorded 30 specific uses for bee products grouped in four categories, from which 29 were attributed (but not exclusively) to Tetragonisca angustula, making it the most versatile species.

CONCLUSIONS

The products of the hive, especially honey, are used for a wide variety of purposes, mostly in medicine. These uses are mostly attributed to just one species, T. angustula, in coincidence with what was taught in meliponiculture training courses by NGOs. The influence of formal knowledge is mostly positive, but it is recommended that other meliponini species are taken into account as well.

Stingless bee Trigona spinipes (Hymenoptera: Apidae) behavior on chayote flowers (Sechium edule)

This experiment aimed to evaluate the forage species and their effect on fruit production of the chayote crop. For this, the culture was under observation in the first ten minutes at each time, from 7:00 am to 6:00 pm, with three repetitions, in each year studied (1994, 2001, 2009 and 2016). With the exception of 2009, Trigona spinipes stingless bees were frequent and constant insects in these flowers between 8:00 am and 1:00 pm, visiting mainly male flowers for nectar collection and due to foraging behavior this stingless bee may be considered a pollinator of the chayote.

Drosophila ecdysone receptor activity-based ex vivo assay to assess the endocrine disruption potential of environmental chemicals

Insect pollinators, critical for both agricultural output and the ecosystem, are declining at an alarming levels partly due to human-made chemicals. Majority of environmental chemicals hamper the endocrine function and studies on the same in insects remain neglected. Here, we report a Drosophila-based ex vivo assay system that employs a reproductive tissue from transgenic males carrying a reporter gene (lacZ) downstream of ecdysone receptor response element (EcRE) and permits the evaluation of chemical-mediated activity modulation of all three isoforms of ecdysone receptor, which are critical for male fertility. We show agonistic [plasticizers, cypermethrin, atrazine, methyl parathion, imidacloprid, cadmium chloride, mercuric chloride or 3-(4-methylbenzylidene) camphor] or antagonistic (apigenin, tributyltin chloride) effects or lack of effect thereof (rutin hydrate, dichlorvos, lead acetate, parabens) for seven different classes of environmental chemicals on ecdysone receptor activity reflecting the specificity and sensitivity of the developed ex vivo assay. Exposure to a few of these chemicals in vivo hampers the fertility of Drosophila males, thus linking the observed endocrine disruption to a quantifiable reproductive phenotype. The developed ex vivo assay offers a quick Drosophila-based screening tool for throughput monitoring of environmental chemicals for their ability to hamper the endocrine function of insect pollinators and other invertebrates.

Managed pollination is a much better way of increasing productivity and essential oil content of dill seeds crop

Dill seeds (Anethumgraveolens L.) is the most valuable medicinal seed spice crop of Apiaceae. It bears small yellow flowers in the form of umbels. Being a cross-pollinated crop, floral visitors play vital role in pollination and seed sets. Hence, the present study was conducted at the ICAR-National Research Centre on Seed Spices, Ajmer (Rajasthan), India to discover the pollinator’s community, foraging behaviour and abundance of most frequent pollinators and different modes of pollination on seed yield and quality of this seed spice crop. The insect visitors community of dill seeds was composed of 28 insect species belonging to 14 families of 6 orders. Most of floral visitors started their foraging activity at 8.00 h, reached peak activity between 12.00 and 14.00 h and their activity ceased at 18.00 h. Apisflorea,A.dorsata,A.mellifera, solitary bee, Halictus sp. and two unidentified species of Hymenoptera; Episyrphusbalteatus (DeGeer), Episyrphus sp., Eristalis sp and two other Musca species of Diptera were identified as potential and regular floral visitors of dill seeds. The highest seed yield of 1505.63 kg/ha was recorded in the treated plots provided with only 10% jaggery solution and was at par with the open pollination. A lower seed yield of 1432.5 kg/ha was recorded in plots pollinated only with A.mellifera inside insect cages. Open pollination with 10% jaggery solution spray increased the seed yield of dill seed crop by 57%, one-thousand seed test weight by 96% and the essential oil content by 27% over control plots. These results show that managed pollination is a much better way to enhance yields and quality of dill seed crop than other treatments including only honeybee-based pollination.

Management of Centris analis (Hymenoptera: Apidae): Investigating the Ideal Dimensions of Trap Nests for Use in Crop Pollination

Centris analis (Fabricius, 1804) is a solitary, cavity-nesting bee that is often recorded in studies through the use of trap nests. This species is considered to be a good candidate as a manageable pollinator for some orchards. However, further studies are still needed to optimize its rational rearing. This study sought to analyze female preference for different lengths and diameters of trap nests, as well as the effects of nest dimensions on the number of constructed cells, mortality rates, parasitism rates, and sex ratio. We used compact trap nests comprised of tubes with internal diameters ranging from 0.6 to 0.8 cm, and lengths ranging from 8 to 12 cm. The results showed that females preferred the narrowest (0.6 and 0.7 cm) and two of the longest cavities (10 and 12 cm). The greatest number of cells built was observed in the most used lengths. The lengths that were tested did not affect the mortality or parasitism rates or the sex ratio. Based on our findings concerning the dimensions examined, we recommend using the narrowest and longest cavities. The combined analyses of the tested parameters (diameter and length) demonstrated new data that can help improve the rearing and maintenance techniques applied to C. analis populations.

Machine learning approach for automatic recognition of tomato-pollinating bees based on their buzzing-sounds

Bee-mediated pollination greatly increases the size and weight of tomato fruits. Therefore, distinguishing between the local set of bees–those that are efficient pollinators–is essential to improve the economic returns for farmers. To achieve this, it is important to know the identity of the visiting bees. Nevertheless, the traditional taxonomic identification of bees is not an easy task, requiring the participation of experts and the use of specialized equipment. Due to these limitations, the development and implementation of new technologies for the automatic recognition of bees become relevant. Hence, we aim to verify the capacity of Machine Learning (ML) algorithms in recognizing the taxonomic identity of visiting bees to tomato flowers based on the characteristics of their buzzing sounds. We compared the performance of the ML algorithms combined with the Mel Frequency Cepstral Coefficients (MFCC) and with classifications based solely on the fundamental frequency, leading to a direct comparison between the two approaches. In fact, some classifiers powered by the MFCC–especially the SVM–achieved better performance compared to the randomized and sound frequency-based trials. Moreover, the buzzing sounds produced during sonication were more relevant for the taxonomic recognition of bee species than analysis based on flight sounds alone. On the other hand, the ML classifiers performed better in recognizing bees genera based on flight sounds. Despite that, the maximum accuracy obtained here (73.39% by SVM) is still low compared to ML standards. Further studies analyzing larger recording samples, and applying unsupervised learning systems may yield better classification performance. Therefore, ML techniques could be used to automate the taxonomic recognition of flower-visiting bees of the cultivated tomato and other buzz-pollinated crops. This would be an interesting option for farmers and other professionals who have no experience in bee taxonomy but are interested in improving crop yields by increasing pollination.

Bees are the most important pollinators of cultivated tomatoes. We also know that the distinct species of bees have different performances as pollinators, and these performances are directly related to the size and weight of the fruits. Moreover, the characteristics of the buzzing sounds tend to vary between the bee species. However, the buzzing sounds are complex and can widely vary over time, making the analysis of this data difficult using the usual statistical methods in Ecology. In the face of this problem, we proposed to automatically recognize pollinating bees of tomato flowers based on their buzzing sounds using Machine Learning (ML) tools. In fact, we found that the ML algorithms are capable of recognizing bees just based on their buzzing sounds. This could lead to automating the recognition of flower-visiting bees of the cultivated tomato, which would be a nice option for farmers and other professionals who have no experience in bee taxonomy but are interested in improving crop yields. On the other hand, this encourages the farmer to adopt sustainable agricultural practices for the conservation of native tomato pollinators. To achieve this goal, the next step is to develop applications compatible with smartphones capable of recognizing bees by their buzzing sounds.

Areas Requiring Restoration Efforts are a Complementary Opportunity to Support the Demand for Pollination Services in Brazil

Crop pollination is one of Nature's Contributions to People (NCP) that reconciles biodiversity conservation and agricultural production. NCP benefits vary across space, including among distinct political-administrative levels within nations. Moreover, initiatives to restore ecosystems may enhance NCP provision, such as crop pollination delivered by native pollinators. We mapped crop pollination demand (PD), diversity of pollinator-dependent crops, and vegetation deficit (VD) (vis-a-vis Brazilian legal requirements) across all 5570 municipalities in Brazil. Pollinator-dependent crops represented ∼55% of the annual monetary value of agricultural production and ∼15% of the annual crop production. Municipalities with greater crop PD (i.e., higher degree of pollinator dependence of crop production) also had greater VD, associated with large properties and monocultures. In contrast, municipalities with a greater diversity of pollinator-dependent crops and predominantly small properties presented a smaller VD. Our results support that ecological restoration prompted by legal requirements offers great potential to promote crop productivity in larger properties. Moreover, conservation of vegetation remnants could support food security in small properties. We provided the first steps to identify spatial patterns linking biodiversity conservation and pollination service. Using Brazilian legal requirements as an example, we show that land-use management policies may be successfully used to ensure agricultural sustainability and crop production.

Effects of Insecticides and Microbiological Contaminants on Apis mellifera Health

Over the past two decades, there has been an alarming decline in the number of honey bee colonies. This phenomenon is called Colony Collapse Disorder (CCD). Bee products play a significant role in human life and have a huge impact on agriculture, therefore bees are an economically important species. Honey has found its healing application in various sectors of human life, as well as other bee products such as royal jelly, propolis, and bee pollen. There are many putative factors of CCD, such as air pollution, GMO, viruses, or predators (such as wasps and hornets). It is, however, believed that pesticides and microorganisms play a huge role in the mass extinction of bee colonies. Insecticides are chemicals that are dangerous to both humans and the environment. They can cause enormous damage to bees' nervous system and permanently weaken their immune system, making them vulnerable to other factors. Some of the insecticides that negatively affect bees are, for example, neonicotinoids, coumaphos, and chlorpyrifos. Microorganisms can cause various diseases in bees, weakening the health of the colony and often resulting in its extinction. Infection with microorganisms may result in the need to dispose of the entire hive to prevent the spread of pathogens to other hives. Many aspects of the impact of pesticides and microorganisms on bees are still unclear. The need to deepen knowledge in this matter is crucial, bearing in mind how important these animals are for human life.

Temporal Trends in Pollination Deficits and Its Potential Impacts on Chinese Agriculture

Worldwide, there is increasing evidence that shows a decline in pollinators, limiting crop pollination and production. However, it is unclear to what extent Chinese agriculture could be impacted by pollinator deficits. Data for 84 major crops in China between 1961 and 2018 were analyzed for the temporal trends in crop area and production, agricultural economic contribution of pollination, crop yield deficits, and honey bee pollination demand. We found a rapid increase in agricultural dependence on insect pollinators: both the cultivated area and total production of pollinator-dependent crops increased faster than those of pollinator-independent crops during 1961-2018. The total economic value of pollination amounted to US$ 106.08 billion in 2010, representing 19.12% of the total production value of Chinese agriculture, approximately twice the 9.5% value estimated for global agriculture. Crops with higher pollinator dependence showed greater mean growth in cultivated area than those with lower dependence, but lower mean growth of crop production and yield. Crop yield growth was also more unstable with increasing pollinator dependence. The minimum pollination demand for honey bee colonies was about three times the stock of honey bee colonies available in 2018. Furthermore, we found a decline in crop yield deficit with the increase in honey bee colony pollination service capacity. We considered that the shortage of pollinators resulted in the yield deficits for pollinator-dependent crops. Future increase in the area of pollinator-dependent crops will increase the need for more pollinators, suggesting the importance of implementing measures to protect pollinators to ensure a better-secured future for agricultural production in China.

Overview of Bee Pollination and Its Economic Value for Crop Production

Simple Summary

There is a rising demand for food security in the face of threats posed by a growing human population. Bees as an insect play a crucial role in crop pollination alongside other animal pollinators such as bats, birds, beetles, moths, hoverflies, wasps, thrips, and butterflies and other vectors such as wind and water. Bees contribute to the global food supply via pollinating a wide range of crops, including fruits, vegetables, oilseeds, legumes, etc. The economic benefit of bees to food production per year was reported including the cash crops, i.e., coffee, cocoa, almond and soybean, compared to self-pollination. Bee pollination improves the quality and quantity of fruits, nuts, and oils. Bee colonies are faced with many challenges that influence their growth, reproduction, and sustainability, particularly climate change, pesticides, land use, and management strength, so it is important to highlight these factors for the sake of gainful pollination.

Abstract

Pollination plays a significant role in the agriculture sector and serves as a basic pillar for crop production. Plants depend on vectors to move pollen, which can include water, wind, and animal pollinators like bats, moths, hoverflies, birds, bees, butterflies, wasps, thrips, and beetles. Cultivated plants are typically pollinated by animals. Animal-based pollination contributes to 30% of global food production, and bee-pollinated crops contribute to approximately one-third of the total human dietary supply. Bees are considered significant pollinators due to their effectiveness and wide availability. Bee pollination provides excellent value to crop quality and quantity, improving global economic and dietary outcomes. This review highlights the role played by bee pollination, which influences the economy, and enlists the different types of bees and other insects associated with pollination.

Technological Advances to Reduce Apis mellifera Mortality: A Bibliometric Analysis

Bees play a fundamental role in the ecological balance of ecosystems, due to the pollination process they carry out on crops, including the production of honey. However, the mortality of bees is a significant concern; bee mortality can occur for several reasons, such as pesticides, mites, viruses, climate change, pathogens and a reduction in food resources and nests. The honey bee (Apis mellifera) is the most widely used bee for commercial pollination and honey production. Therefore, the main objective is to compare the development of patent families and article publications related to the reduction in A. meliífera mortality. Data on patent families were collected on the Orbit platform, while data on scientific articles were collected on the Scopus database, with a time interval of 1980–2019. Subsequently, the data were analyzed in order to show the main priority countries, main assignees, and main IPC (International Patent Classification) codes, an analysis of the technology life cycle and the correlation between the data of patent families and articles published. The technologies that help to decrease bee mortality showed a technological maturity rate of 27.15% for patent families data and 53.35% for data from articles published in journals. It was noticed that the principal interest regarding the reduction in A. mellifera mortality is focused on universities, mainly in the United States and China.

Effects of native forest and human-modified land covers on the accumulation of toxic metals and metalloids in the tropical bee Tetragonisca angustula

The intensive shift on land cover by anthropogenic activities have led to changes in natural habitats and environmental contamination, which can ultimately impact and threat biodiversity and ecosystem services, such as pollination. The aim of this study was to evaluate the effect of native forest and human-modified land covers on the concentrations of chemical elements accumulated in the neotropical pollinator bee T. angustula. Eight landscapes, within an Ecological Corridor in the State of São Paulo, Brazil, with gradients of forest cover, spatial heterogeneity and varying land covers were used as sampling unities. Bees collected in traps or through actives searches had the concentration of 21 chemical elements determined by ICP-MS. Results show a beneficial effect of forested areas on the concentrations of some well-known toxic elements accumulated in bees, such as Hg, Cd, and Cr. Multivariate Redundancy Analysis (RDA) suggests road as the most important driver for the levels of Cr, Hg, Sb, Al, U, As, Pb and Pt and bare soil, pasture and urban areas as the landscape covers responsible for the concentrations of Zn, Cd, Mn, Mg, Ba and Sr in bees. The results reinforce the potential use of T. angustula bees as bioindicators of environmental quality and also show that these organisms are being directly affected by human land use, offering potential risks for the Neotropical ecosystem. Our study sheds light on how land covers (native forest and human-modified) can influence the levels of contaminants in insects within human-dominated landscapes. The generation of predictions of the levels of toxic metals and metalloids based on land use can both contribute to friendly farming planning as well as to support public policy development on the surrounding of protected areas and biodiversity conservation hotspots.

Bees and pesticides: the research impact and scientometrics relations

Bees are fundamental insects in agroecosystems, mainly due to pollination. However, its decline has been observed in recent years, and the contamination by pesticides is suspected to be responsible. This relationship is the objective of our research, which is the first scientometric study on this subject. The data were obtained from the Web of Science database (1231) and were analyzed using Microsoft Office Excel and CiteSpace. The results point to a significant increase in pesticide and bee reseach in the last 15 years in the most influential scientific journals. The USA and France have the largest number of publications and a moderade relationship between this trait and GDP (gross domestic product) was observed (r = 0.80; r2 = 0.60). There is no correlation between the use of pesticides and studies of the effects on pollinators and the use of pesticides and the countries' GDP. In general, studies have shown the negative effects of the contamination by pesticides on bees; however, most publications are with bees of the Apis genus, and therefore it is necessary to explore the action of pesticides on bumble bees and wild bees, as well furthur as studies are needed regarding the sublethal effects of these products on bees as the number of molecules used in the management of agricultural crops is vast.

Edible Fruit Plant Species in the Amazon Forest Rely Mostly on Bees and Beetles as Pollinators

Edible fruit plants of tropical forests are important for the subsistence of traditional communities. Understanding the most important pollinators related to fruit and seed production of these plants is a necessary step to protect their pollination service and assure the food security of these communities. However, there are many important knowledge gaps related to floral biology and pollination in megadiverse tropical rainforests, such as the Amazon Forest, due mainly to the high number of plant species. Our study aims to indicate the main pollinators of edible plants (mainly fruits) of the Amazon forest. For this, we adopted a threefold strategy: we built a list of edible plant species, determined the pollination syndrome of each species, and performed a review on the scientific literature searching for their pollinator/visitors. The list of plant species was determined from two specialized publications on Amazon fruit plants, totaling 188 species. The pollination syndrome was determined for 161 species. The syndromes most frequently found among the analyzed species were melittophily (bee pollination), which was found in 101 of the analyzed plant species (54%) and cantharophily (beetle pollination; 26 species; 14%). We also found 238 pollinator/visitor taxa quoted for 52 (28%) plant species in previous publications, with 124 taxa belonging to Apidae family (bees; 52%), mainly from Meliponini tribe (58 taxa; 47%). Knowledge about pollinators is an important step to help on preserving their ecosystem services and maintaining the productivity of fruit trees in the Amazon.

Larvae of stingless bee Scaptotrigona bipunctata exposed to organophosphorus pesticide develop into lighter, smaller and deformed adult workers

Organophosphorus pesticides such as chlorpyrifos are often used in agriculture due to their broad spectrum of action. However, this insecticide and acaricide is considered highly toxic to the environment and can cause toxicity in nontarget insects such as bees. In addition to adult individuals, immature can also be exposed to residues of this insecticide by larval food. Thus, we investigated the effects of chlorpyrifos concentrations on the larval development of stingless bee Scaptotrigona bipunctata workers reared in vitro. We evaluated four different biomarkers: a) survival, b) development time, c) body mass and d) morphological characteristics (head width, intertegular distance, wing area and proportion of deformed bees). The exposure of the larvae to different doses of chlorpyrifos significantly reduced survival probability but did not cause changes in the development time. Regarding morphometric analysis, bees exposed to chlorpyrifos showed a reduction in body mass and size, and 28% of the emerged adults showed a reduction in wing area and deformations. Therefore, this work shows that S. bipunctata larvae exposed to the sublethal effects of chlorpyrifos are likely to have reduced chances of survival. However, if they emerge, they will be lighter, smaller and less able than equivalent but not exposed workers. These impaired attributes have the potential to compromise the future workforce in colonies exposed to this pesticide.

Possible interference of Bacillus thuringiensis in the survival and behavior of Africanized honey bees (Apis mellifera)

Bacillus thuringiensis (Bt), an entomopathogenic bacterium, has been used as bioinsecticides for insect pest control worldwide. Consequently, the objective of this work was to evaluate the possible effects of commercial formulations of Bt products, Dipel and Xentari, on the survival and behavior of Africanized honey bees (Apis mellifera). Bioassays were performed on foragers and newly emerged (24-h-old) bees that received the products mixed in the food. Their survival and behavior were evaluated through the vertical displacement tests and the walk test, analyzed using software Bee-Move. Then, histological analysis of the mesenterium was performed. As control treatment was used sterile water. The honey bees' survival was evaluated for between 1 and 144 h. No interference of B. thuringiensis, Dipel and Xentari, in the survival of Africanized honey bees were found. Only Xentari interfered with vertical displacement behavior of newly emerged (24-h-old) bees. Both the products tested were selective and safe for A. mellifera.

Ecosystem Services Provided by Insects in Brazil: What Do We Really Know?

Insects are the most abundant and diverse organisms on Earth and provide essential ecosystem services. However, Brazilian society rarely consider the importance of insects in their diverse country. Therefore, in this review, we provide an overview of ecosystem services provided by insects in Brazil. A database search returned 136 articles, published in English or Portuguese, on ecosystem services provided by insects in Brazil. The first article was published in 1982, and majority of the studies were conducted in the Atlantic Forest or the Cerrado biomes. The most frequently studied insect-provided ecosystem services were pollination, decomposition, and biological control of pests. The studies focused primarily on natural and anthropic ecosystems, and most followed an experimental approach. We noted that the term "ecosystem services" was not used frequently in studies on insects in Brazil. The information available was mostly taxon-biased. We discuss the implications of these findings in relation to reconciling economic interests and the need for insect conservation for continued provision of ecosystem services in a broader perspective. In conclusion, we argue that the scientific community should focus on understanding the ecosystem services provided by insects other than those strictly related to economic activities, and on improving communication with policymakers and citizens. As a tropical and megadiverse country, Brazil has the potential to become a protagonist in conserving and using the ecosystem services provided by insects, both locally and internationally, by providing scientific information to policymakers and citizens.

The effects of field-realistic doses of imidacloprid on Melipona quadrifasciata (Apidae: Meliponini) workers

The presence of Brazilian native bees can improve tomato production by increasing pollination effectiveness. However, the extensive use of pesticides in tomato cultures may be harmful to bees. Imidacloprid-based insecticides are used in tomato plantations because of its high efficiency against tomato pests. This study investigated the effects of oral intake of field-realistic concentrations of imidacloprid by M. quadrifasciata workers, a stingless native bee from Brazil and effective pollinators of tomato crops. The oral intake of sucrose syrup added with 10, 35, or 70 ppb of imidacloprid did not increase the mortality rate when compared with the control group. However, we observed a reduction in the workers' motility and food consumption. We also treated M. quadrifasciata workers with sucrose syrup mixed with an imidacloprid-based insecticide (Evidence 700 WG®, Bayer), with the final concentration of 250 ppb of imidacloprid. This treatment did not cause visible alterations of the intestine absorptive cells of the bees' midgut and did not increase DNA damage. Therefore, the observed reduction of food consumption and locomotion behavior of M. quadrifasciata workers may contribute to the global effort to understand the contribution of neonicotinoids on bees' population decline process.

Model approaches to estimate spatial distribution of bee species richness and soybean production in the Brazilian Cerrado during 2000 to 2015

Agricultural expansion as a main human activity has affected pollinator's habitat, causing spatial distribution changes. Meanwhile, pollinators still provide pollination service to improve crop production. However, their spatial response is unclear because of environmental changes. This study sought to estimate spatial distribution of crop production and pollinator's richness, which can provide insights as to how they interact with the environment. We acquired environmental variables from remote sensing images and used a stacked species distribution model to predict selected bee species richness and a crop simulation model to simulate and calculate soybean production at a regional scale in the Cerrado for the period 2000-2015. Then, we analyzed their potential relationship. The results showed that higher selected bee species richness and higher soybean production occurred in the southern Cerrado. From 2000/08 to 2008/15 period, the selected bee species richness significantly decreased in the western part of the state of Bahia, the state of Goiás, and the northern region of the state of Minas Gerais; while soybean production increased in the states of Mato Grosso, Goiás, Bahia, and Tocantins. Correlation results of selected bee species richness and soybean production showed that they do not follow a linear relationship during the study period. Our findings indicate that the modeling method we proposed is robust to estimate spatial distribution of bee species richness and soybean production in the Cerrado at the regional scale and that the environment has a stronger influence on selected bee species richness than on soybean production. Moreover, climate effects and agricultural expansion are the main factors that affect their spatial distribution and interaction. Finally, our methodology provides a novel spatial perspective to analyze the relationship between pollinator and agricultural expansion corresponding with the environment, but future work is needed to collect a more comprehensive data set to improve model results.

Diversity of Floral Visitors in Apple Orchards: Influence on Fruit Characteristics Depends on Apple Cultivar

Most cultivars of apple trees are highly dependent on insects for successful pollination and fruit production. In this study, we evaluated the insect diversity in apple orchards of southern Brazil and verified whether or not there is a relationship between the diversity of insect visitors and the characteristics (weight, seed number, and symmetry) of the fruits of 'Fuji' and 'Gala' apples produced by the orchards. We also evaluated the diversity of insects on flowering weeds within apple orchards and compared it with the apple flowers. Diversity of anthophilous insects was low, in general, and differed between the regions. Furthermore, regarding insect diversity, orchards were grouped by management system: organic orchards were more similar to each other than to conventional orchards. The insect diversity of weed flowers was higher than apple flowers, but insect abundance was greater on apple flowers, suggesting that weeds may increase insect diversity within apple orchards and may sustain pollinators. We found a positive effect of insect diversity on the number of seeds of 'Fuji' apples and of honeybee abundance on their weight, suggesting that honeybee management is important in the studied areas. In contrast, we found no significant effect of insect diversity and abundance on 'Gala' apple characteristics. Despite this, the analyses of the seeds of 'Gala' apples indicate that the orchards may suffer a pollination deficit, which could be overcome by improving insect pollination. These results reinforce previous findings that insect diversity is important for apple yield, but its influence varies with cultivar.

The Value of Crop Production and Pollination Services in the Eastern Amazon

Nature safeguards living organisms and the ecosystem functions and services delivered by them. Animal pollination is an important Ecosystem Service since it plays a key role for achieving the sustainable development goals by safeguarding worldwide food production. Thus, conservation of pollination services is a major priority for guaranteeing global food security in the long term. Here we evaluate the crop pollination services in Pará state (Eastern Amazon, Brazil) focusing on two questions: (1) What is the economic value of crop production and pollination service in Pará? (2) Which municipalities are most dependent on pollination services considering local economies? We found 36 crops produced in the state; 20 (55%) crops are dependent on animal pollinators. In 2016, crop production value (CPV) for Pará state was US$ 2.95 billion and total pollination service value (PSV) was US$ 983.2 million, corresponding to 33% of CPV in Pará. Highest PSV value crops were açaí palm (US$635.6 million), cocoa (US$187.6 million), soybean (US$98.4 million), and watermelon (US$26.1 million), accounting for 96% of Pará's PSV. Two municipalities (Medicilândia and Igarapé Miri) presented more than 50% of their GDP based on pollination services. In general, we found low crop diversity in the municipalities of Pará, suggesting an economic rural vulnerability for the state, mainly supported by the high productions of soy and açaí. Pollinator conservation and ecological intensified farming practices are urgent for supporting sustainable development for the state.

Toxicity of insecticides on Neotropical stingless bees Plebeia emerina (Friese) and Tetragonisca fiebrigi (Schwarz) (Hymenoptera: Apidae: Meliponini)

Use of pesticides in agroecosystems is considered a major cause of bees diversity losses in the Neotropics, where Plebeia emerina (Friese) and Tetragonisca fiebrigi (Schwarz) (Hymenoptera: Apidae: Meliponini) are wild pollinators of native and crop plants. The aim of this study was to know the acute lethal toxicity of acetamiprid, malathion, phosmet and spinosad insecticides on P. emerina and T. fiebrigi. We obtained the mean concentration and mean lethal dose (LC₅₀ and LD₅₀) and the mean survival of workers after oral and topical exposure to insecticides, respectively. The LC₅₀ values (ng a.i./μl of diet) and the decreasing order of toxicity for P. emerina was spinosad (4.96) > malathion (18.75) > phosmet (97.33) > acetamiprid (4204.06), and for T. fiebrigi also was spinosad (5.65) > malathion (8.39) > phosmet (53.91) > acetamiprid (9841.32), when orally exposed. The LD₅₀ values (ng a.i./bee) and the decreasing order of toxicity for P. emerina was spinosad (1.90) > malathion (10.90) > phosmet (19.54) > acetamiprid (6216.55) and for T. fiebrigi was malathion (29.29) ≥ spinosad (29.79) > phosmet (41.95) > acetamiprid (1421.23), when topically exposed. The mean survival (hours) of contaminated bees by malathion, phosmet, and spinosad, was 11.81, 7.20, and 12.32 for P. emerina and 8.55, 7.20, and 13.34 for T. fiebrigi when orally exposed; and was 4.87, 9.87 and 11.17 for P. emerina, and 4.87, 4.76, and 19.05 for T. fiebrigi when topically exposed. Malathion, phosmet, and spinosad were highly toxic, while acetamiprid was moderately toxic. Our results indicated that the insecticides tested, mainly malathion, phosmet, and spinosad may be harmful to P. emerina and T. fiebrigi, making it essential to propose measures to minimize their impact on wild pollinators.

Pollination service of Nannotrigona testaceicornis stingless bees in strawberry

ABSTRACT Strawberry presents moderate dependence on bee pollination service, and pollination is related to the production and quality of fruits. The aim of this study was to evaluate the pollination service provided by Nannotrigona testaceicornis stingless bees in strawberry. Primary flowers of cultivar San Andreas were used in a completely randomized experimental design, with twelve replicates and five types of pollination: one N. testaceicornis visit (1V); two N. testaceicornis visits (2V); three N. testaceicornis visits (3V); natural pollination (NP); self-pollination (SP). In flowers visited by N. testaceicornis, movements and visit time were observed. The following fruit characteristics were evaluated: fruit biometry, fecundation rate of achenes, postharvest fruit quality, contribution of pollination agents and mechanisms on average fruit weight. In fruit biometry, pollination service contributed only in longitudinal length, which was higher in NP and 3V, compared to SP. In the different types of pollination, the fertilization rate of achenes did not differ and showed no effect on fresh fruit weight. In post-harvest fruit quality, 1V, 3V and NP showed better results regarding degree of deformation and marketability. Nannotrigona testaceicornis stingless bees and natural pollination contributed to the average fresh weight of strawberry fruits. Nannotrigona testaceicornis stingless bees and natural pollination provided improvement in quality and added value of fruits. Nannotrigona testaceicornis stingless bees were effective strawberry pollinators.

Honeybee survival and flight capacity are compromised by insecticides used for controlling melon pests in Brazil

The extensive use of insecticides can cause adverse side effects on pollinators, which negatively impact crop productivity. The pollination carried out by the honeybee Apis mellifera L. (Hymenoptera: Apidae) is crucial in increasing the productivity of the melon (Cucumis melo L.). The main objective of this study was to assess if insecticides applied in the cultivation of cantaloupe melon exhibit significant levels of toxicity toward A. mellifera. We tested the toxicity of azadirachtin, pyriproxyfen, chlorantraniliprole, and imidacloprid, which are commonly sprayed to manage melon pests such as the whitefly Bemisia tabaci (Genn.) (Hemiptera: Aleyrodidae), the pickleworm Diaphania nitidalis (Stoll) and the melonworm Diaphania hyalinata (L.) (Lepidoptera: Pyralidae). Three treatments were carried out, 0.0×, 0.1x and 1.0x the concentration recommended by the manufacturer for the control of those pests. Repellency tests, analysis of mortality through contact and ingestion, and flight tests were performed. The insecticide imidacloprid caused mortality rates above 90% in all tested exposure pathways, displaying high residue persistence on plants. Although not causing significant mortality in the ingestion test, pyriproxyfen caused significant mortality after exposure through contact, and change in flight ability. Azadirachtin caused mortality in the ingestion test and impaired the flight ability of bees, while chlorantraniliprole only impaired the flight ability. Moreover, bees were not repelled by these insecticides, suggesting that they may collect contaminated food in the field while foraging. Altogether, ecofriendly, alternative pest control options should be developed, as well as the adoption of more selective insecticides, in order to reduce the non-target effects on honeybees and guarantee their pollination services.

Nanopesticide based on botanical insecticide pyrethrum and its potential effects on honeybees

Nanotechnology has the potential to overcome the challenges of sustainable agriculture, and nanopesticides can control agricultural pests and increase farm productivity with little environmental impact. However, it is important to evaluate their toxicity on non-target organisms, such as honeybees (Apis mellifera) that forage on crops. The aims of this study were to develop a nanopesticide that was based on solid lipid nanoparticles (SLNs) loaded with pyrethrum extract (PYR) and evaluate its physicochemical properties and short-term toxicity on a non-target organism (honeybee). SLN + PYR was physicochemically stable after 120 days. SLN + PYR had a final diameter of 260.8 ± 3.7 nm and a polydispersion index of 0.15 ± 0.02 nm, in comparison with SLN alone that had a diameter of 406.7 ± 6.7 nm and a polydispersion index of 0.39 ± 0.12 nm. SLN + PYR had an encapsulation efficiency of 99%. The survival analysis of honeybees indicated that PYR_10ng presented shorter longevity than those in the control group (P ≤ 0.01). Empty nanoparticles and PYR_10ng caused morphological alterations in the bees' midguts, whereas pyrethrum-loaded nanoparticles had no significant effect on digestive cells, so are considered safer, at least in the short term, for honeybees. These results are important in understanding the effects of nanopesticides on beneficial insects and may decrease the environmental impacts of pesticides.