Tetragonisca Angustula Research Articles

Relações positivas entre insetos e negativos com aranhas em plantas de Acacia auriculiformis (Fabaceae) no bioma savana e seus padrões de distribuição

Forest restoration is mainly based on plant-soil relationships and plant species with economic potential, but those between insects and other arthropods are also important to this reestablishment. The objective was to evaluate, during 24 months, the relationships between tending ants, Hemiptera phytophagous, predators and their distribution pattern (aggregated, random or uniform). The arthropods were sampled, stored and identified and their relationships and distribution patterns calculated with the BioDiversity-Pro software. The number of tending ants and phytophagous Hemiptera, Brachymyrmex sp. and Aethalion reticulatum, Cephalotes and Aleyrodidae were positively correlated. Tending ants were negatively correlated with Sternorrhyncha predators on A. auriculiformis saplings. The distribution of arthropods was aggregated, except for Teudis sp. and Cephalocoema sp., with a random pattern. The herbivores Stereoma anchoralis, Aethalion reticulatum and Tetragonisca angustula and the predators Brachymyrmex sp. and Dolichopodidae were the most abundant arthropods. The relationships between the arthropods studied on A. auriculiformis indicate that this plant, even introduced, is suitable for programs to recover degraded areas in the savannah.

O papel dos testes qualitativos na detecção de adulterantes em mel de abelha sem ferrão: Uma promissora abordagem para produtores e consumidores de mel

Abstract Among the hive products of stingless bees (SB), honey is distinguished because it has different physicochemical properties than the honey produced by Apis mellifera. Its taste is more acidic and less sweet, and it naturally contains a higher percentage of water. Honey is one of the most frequently adulterated products marketed. Therefore, this work aimed to verify if the qualitative tests performed for A. mellifera honey are also valid for SB honey from Tetragonisca angustula, Melipona quadrifasciata, and Tetragona elongata and if they can detect the most common adulterations. Adulterations of SB honey with corn syrup, inverted sugar, and A. mellifera honey were simulated and tested with Lugol, Fiehe, and Lund reactions. For these three analyses, sample volume reduction was also tested. The Lund test did not work well with honey samples from SB because they have a higher water content, and reliable results could not be obtained. For the other two tests, the sample volume reduction used was efficient. The Fiehe test detected adulteration with corn syrup only. The Lugol test detected corn syrup and inverted sugar adulterations in all dilutions for all three SB species. No adulteration by added water or honey from A. mellifera was detected in any test. Therefore, using the qualitative Lugol’s reaction test to evaluate SB honey quality is reasonably affordable. Since it is a rapid and inexpensive test, it allows the development of production chains for SB honey. Thus, detecting inauthentic honey can be done by combining qualitative tests as the first screening, followed by quantitative tests if necessary.

Insects and spiders on Acacia mangium (Fabaceae) saplings as bioindicators for the recovery of tropical degraded areas.

Acacia mangium is a pioneer species with fast growth and frequently used in the recovery of degraded areas. The objectives were to evaluate insects and spiders, their ecological indices and interactions on A. mangium saplings in a tropical degraded area in recovering process. The experimental design was completely randomized with 24 replications, with treatments represented by the first and second years after A. mangium seedling planted. Numbers of leaves/branch, branches/sapling, and ground cover by A. mangium saplings, Hemiptera: Phenacoccus sp. and Pachycoris torridus; Hymenoptera: Tetragonisca angustula and Trigona spinipes, Brachymyrmex sp., Camponotus sp. and Cephalotes sp.; Blattodea: Nasutitermes sp. and Neuroptera: Chrysoperla sp.; abundance, species richness of pollinating insects, tending ants, and the abundance of Sternorrhyncha predators were greatest in the second year after planting. Numbers of Hemiptera: Aethalium reticulatum, Hymenoptera: Camponotus sp., Cephalotes sp., Polybia sp., T. angustula, T. spinipes, tending ants, pollinating insects, Sternorrhyncha predators and species richness of tending ants were highest on A. mangium saplings with greatest numbers of leaves or branches. The increase in the population of arthropods with ground cover by A. mangium saplings age increase indicates the positive impact by this plant on the recovery process of degraded areas.

Ferulic acid as major antioxidant phenolic compound of the Tetragonisca angustula honey collected in Vera Cruz - Itaparica Island, Bahia, Brazil.

The antioxidant activity of Tetragonisca angustula honey (TAH) and its ethanolic extract (TAEE) were investigated. The total levels of phenolic (TPC) and flavonoids (TFC) were also evaluated. The results for TPC were 19.91 ± 0.38 and 29.37 ± 1.82 mg GAE g-1 and for TFC 0.20 ± 0.02 and 0.14 ± 0.01 mg QE g-1 of TAH and TAEE, respectively. Antioxidant activities were 73.29 ± 0.49% and 93.36 ± 0.27% in the DPPH● assay and 71.73 ± 4.07% and 97.86 ± 0.35% in ABTS●+ for TAH and TAEE, respectively. The total reducing activity was determined by the method of reducing power (PR) and iron ion (Fe III) and the results varied in PR from 151.7 ± 25.7 and 230.7 ± 25.2 mg GAE L-1, for TAH and TAEE respectively and for (Fe III) in EC50 0.284 in TAEE and 0.687 in TAH. Chemical analysis by HPLC-DAD of the ethanolic extract (TAEE) revealed the presence of ferulic acid as majority phenolic component in the extract. The 1H NMR analysis confirmed this structure and showed the also presence of glucose, citric acid, succinic acid, proline and hydrocarbon derivatives. In addition, the botanical origin was also investigated and showed a multifloral characteristic, having found 19 pollen types with a botanical predominance of the Anacardiaceae family, with Tapirira pollen occurring as predominant (42.6%) and Schinus as secondary (25.7%). The results showed that T. angustula honey is an interesting source of antioxidant phenolic compounds due to its floral origin and can act as a protector of human health when consumed.

Residual determination and acute toxicity of the neonicotinoid clothianidin in the neotropical stingless bee Tetragonisca angustula Latreille, 1811 (Apidae: Meliponini)

Bees play a crucial role as natural pollinators, ensuring the maintenance and stability of the world’s biodiversity and agricultural crops. Native bees in neotropical regions belong to the Meliponini tribe, a larger group that differs significantly in behavior and biology from honeybees (e.g., Apis mellifera) and solitary bees (e.g., Osmia spp.). Hence, the exposure and effects of pesticides is also likely to vary among these different species. The aim of this study was to develop an analytical method to determine the presence of the neonicotinoid clothianidin in the Brazilian native stingless bee Tetragonisca angustula (local common name: Jataí). The method used for the chemical analysis involved a QuEChERS technique combined with UHPLC-MS/MS analysis. The developed method was subsequently used to analyze collected field samples. In addition, the acute toxicity of the pesticide to T. angustula was evaluated in a laboratory bioassay evaluating both lethal and sublethal endpoints. The analytical method was successfully developed with detection and quantification limits of 1.55 and 5 μg L−1, respectively, along with a linear range of 1–5 ng mL−1. Clothianidin was detected in environmental samples (9.2–32.9 ng g−1), and the exposure experiments demonstrated acute oral toxicity to adults of T. angustula, (24 h-LD50 of 0.16 ng a.i./bee), as well as no significative interference in acetylcholinesterase activity. Considering the obtained toxicity endpoints for T. angustula and those reported in the literature for other bee species, this study revealed that T. angustula is more (lethally) sensitive to clothianidin than other bee species, including those commonly used in environmental risk assessment studies. This thus also supports the call for using native test species in (regional) risk assessment evaluations.

Floral Visitation, Phytochemical and Biological Activities of Bioproducts from Tetragonisca angustula (Hymenoptera, Apidae, Meliponini): A Review.

Tetragonisca angustula (Latreille, 1811) is an indigenous neotropical stingless bee, popularly known as "Jataí", with a wide distribution in the Brazilian territory. T. angustula produces other derivatives such as propolis, geopropolis, fermented (saburá pollen), cerumen and resins, which are important in folk medicine. In this review, the objective was to gather research on the main plant species visited by T. angustula, as well as studies that verified the chemical composition and biological properties of T. angustula bioproducts. The bibliographic review was performed by searching the Scopus, Web of Science, ScienceDirect, and PubMed databases for publications from 2003 to February 2023. We found 78 studies that analyzed the interactions between T. angustula and floral species, with species from the botanical families Fabaceae, Asteraceae, Malvaceae, Bignoniaceae, Solanaceae, Myrtaceae and Lamiaceae being the most reported as the main food sources for this species. The presence of compounds belonging to the class of flavonoids, phenolic acids, terpenoids and alkaloids has been identified by studying the chemical composition of honey, propolis, geopropolis and fermented pollen (saburá) in 21 studies. The data collected in the literature emphasize that these T. angustula products have remarkable biological properties, especially their antibacterial and antioxidant activities.

Weeds as an essential component of sustainable meliponiculture practices in organic agroecosystem

Knowledge of bee flora is key information for sustainable meliponiculture practices. Aiming to stablish the plant species used by the stingless bee Tetragonisca angustula used as food sources during the year in an organic agroecosystem, this study identified the pollen grains in the pollen loads of worker bees. The pollen load of bees returning to hives was collected bi-monthly for one year, summing 240 pollen loads analyzed by optical microscopy. We found 76 pollen types in the pollen loads, of which 60% were of weeds. The plants most frequently identified in the pollen loads were: Alchornea, Arracacia xanthorrhiza, Baccharis, Bidens pilosa, Brassica juncea, Brassica oleracea, Byrsonima sp., Cecropia, Chamaecrista, Citrus sp., Crotalaria sp., Croton, Datura, Eucalyptus, Hyptis, Lippia alba, Mangifera indica, Melastomataceae sp., Momordica charantia, Myrsine, Pereskia aculeata, Persea americana, Piptadenia, Pisum sativum, Plinia peruviana, Pluchea, Poaceae, Prunus persica, Psidium guajava, Raphanus sativus, Rubus urticifolius, Schefflera, and Schinus. Bees foraged mostly on weeds, especially during winter and autumn, and so the presence of weeds can be very beneficial to meliponiculture practices. The by-products of meliponiculture in agroecosystems are derived from diversified botanical sources, that is, wild honey of good quality because it is from an organic system.

Physicochemical parameters and chemoprofiling of honey of two species of stingless bees in the Peruvian Amazon

The physicochemical and chemical characteristics of stingless bee honey from two commonly grown species in the Peruvian Amazon, Melipona eburnea and Tetragonisca angustula, were evaluated. Key physicochemical findings include humidity levels exceeding Codex-Alimentarius limits (28.13 g/100 g of honey for M. eburnea and 26.33 g/100 g for T. angustula), while sugar content fell below minimum requirements (54.3 g/100 g of honey and 43.5, respectively). Hydroxymethylfurfural levels were 12.5 mg/100 g of honey and 0.4, respectively. Using MALDI-TOF/TOF analysis, biologically and medicinally relevant molecules derived from plants and microbes were tentatively detected in both honey samples. These molecules encompassed properties such as anticancer, antibacterial, antifungal, anti-inflammatory, and antiviral. Notable compounds in M. eburnea honey included naringenin chalcone, caffeine, berberine, and glycosyl trans-zeatin-O-glucoside, previously documented in various honey types. Additionally, quinine, paclitaxel, stigmastonol, and surfactin C, with therapeutic potential, were preliminarily detected for the first time in this honey. T. angustula honey also contained medicinal molecules including lutein, cinnamic acid, fraxin, and hyperoside, along with newly observed compounds such as osthole, culmorin, and uncarine C (cat’s claw). Both honey samples exhibited trace levels of non-natural compounds, including commercial pesticides and herbicides, suggesting environmental contaminants. Further research is needed to verify the identity of these molecules, understand their potential sources, quantify their levels in Amazonian honey, and assess consumption and health implications. This study highlights the necessity for a novel technical standard exclusive to stingless bee honey, encompassing methodologies for measuring the physicochemical parameters and for monitoring the chemical profile to assess the medicinal potential of native honey and define maximum limits for environmental pollutants. This pioneering work underscores the ecological, medicinal, and economic value of stingless bees in the Peruvian Amazon.

A new cyclodipeptide from Tetragonisca angustula honey active against Neospora caninum and in silico study

A new cyclic natural compound formed by succinic acid and two alanine amino acid units was isolated from the Tetragonisca angustula honey extract. The chemical structure of 1 was established based on spectroscopic data analysis, including one- (1H and 13C NMR) and two-dimensional NMR techniques (1H-1H-COSY, HSQC and HMBC). A primary culture model previously infected with Neospora caninum was used to evaluate 1 for two time intervals (24 and 72 h), showing a reduction (40-56%) of the number of tachyzoites in the first 24 h and until 72 h, a dose-dependent reduction in parasite proliferation (25-50%). Glial cells treated with 1 did not demonstrate toxicity at concentrations up to 25 ug/mL. Treated and infected cultures showed an increase in NO when compared to control cells in 24 h and 72 h. In silico studies suggest that the new compound may affect DNA synthesis and impair ­protein production.

Pollen quality assessment of Tetragonisca angustula, Melipona quadrifasciata and Apis mellifera

Pollen is a product originating from the anthers of flowers. Members of the Apidae group feed on this floristic product, which is metabolized and stored in the hives. It is known that the pollen metabolized by stingless and stingless bees has medicinal and nutritional characteristics. This study aimed to evaluate the physicochemical and microbiological quality of pollen collected by Tetragonisca angustula, Melipona quadrifasciata and Apis mellifera. Pollen was collected between January 2021 and January 2023 in a conservation area in Goiás, Brazil. The pollen was characterized by physicalchemical analysis for moisture, ash, proteins, lipids, total sugars and pH, and microbiological analysis on Escherichia coli and Salmonella spp. The obtained results characterize the pollens of indigenous bees as suitable for consumption, since they presented good physicochemical characteristics for most of the analyzed parameters and free of pathogens.

Comparative morphology of the third pair of legs in drones and workers of Tetragonisca angustula (Hymenoptera: Apidae)

The stingless bees are important models for behavioral studies. The most complex level of social behavior is exhibited by bee species that have a high degree of morphological variation between castes. The drone is often overlooked due to its limited functions. Comparative biology studies would help expand our knowledge of this sex. The aim of this study was to compare the microscopic structures of the third pair of legs of drones and workers of Tetragonisca angustula. We found similarities and differences that contribute to our knowledge of the behavior of stingless bees. To our knowledge, this is the first study on the microscopic comparison of structures of the third pair of legs of drones and workers of Tetragonisca angustula.

Glyphosate-based formulation affects Tetragonisca angustula worker's locomotion, behavior and biology.

Declining bee populations diminish pollination services, damaging plant and agricultural biodiversity. One of the causes of this decline is the use of pesticides. Pesticides with glyphosate as the main active ingredient are among the most used pesticides worldwide, being the most used in Brazil. This study determined the 24 and 48 h LD50 (median lethal dose) of the herbicide's glyphosate-based formulation by ingestion, identified sublethal doses, and investigated its effects on the locomotion and behavior of Tetragonisca angustula workers. The LD50 found indicates that a glyphosate-based formulation is highly toxic to T. angustula. The doses applied, including concentrations found in nature, caused death, motor changes (decreased speed and tremors), excessive self-cleaning, and disorientation (return to light and stop). Although we did not test for pollination effects, we can infer from our results that this formulation can negatively affect the pollination activity of T. angustula. Evaluation of the toxicity and sublethal effects of pesticides on bees contributes to a better understanding of their harmful effects on hives and allows for the development of strategies to reduce these impacts.

Physicochemical characterization and acceptance of honey from stingless bees

This work aimed to perform the physicochemical characterization of honey from stingless bees and correlate it with consumers’ sensory acceptance and purchase intention. Three honeys from native stingless bees, Tetragonisca angustula, Melipona quadrifasciata quadrifasciata and Scaptotrigona postica, were considered. Physicochemical characterization, such as determining water activity, moisture content, pH, free acidity, color, total soluble solids, total phenolic compounds, hydroxymethylfurfural (HMF), and mineral substances, was performed. Tetragonisca angustula showed the lowest water activity and moisture content and could produce honey with a higher concentration of total soluble solids (TSS). The honey types of the other two species studied had lower TSS concentrations and higher moisture and total acidity concentrations. The primary elements in all honey types analyzed were K, Na, P, Ca, and Mg. The honey that had the best evaluation in the purchase intention analysis was Tetragonisca angustula due to its composition; it is sweeter and slightly acidic, with intermediate concentrations of TSS, the highest concentration of phenolic compounds, and the significant presence of chemical elements. It was evidenced that the need to regulate the physicochemical and microbiological quality standards of honey produced in Brazil significantly to contemplate honey’s unique characteristics from native stingless bees.

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.

Bacteria, yeasts, and fungi associated with larval food of Brazilian native stingless bees

Stingless bees are a diverse group with a relevant role in pollinating native species. Its diet is rich in carbohydrates and proteins, by collecting pollen and nectar supplies the development of its offspring. Fermentation of these products is associated with microorganisms in the colony. However, the composition of microorganisms that comprise this microbiome and its fundamental role in colony development is still unclear. To characterize the colonizing microorganisms of larval food in the brood cells of stingless bees Frieseomelitta varia, Melipona quadrifasciata, Melipona scutellaris, and Tetragonisca angustula, we have utilized molecular and culture-based techniques. Bacteria of the phyla Firmicutes, Proteobacteria, Actinobacteria, and fungi of the phyla Ascomycota, Basidiomycota, Mucoromycota, and Mortierellomycota were found. Diversity analysis showed that F. varia had a greater diversity of bacteria in its microbiota, and T. angustula had a greater diversity of fungi. The isolation technique allowed the identification of 189 bacteria and 75 fungi. In summary, this research showed bacteria and fungi associated with the species F. varia, M. quadrifasciata, M. scutellaris, and T. angustula, which may play an essential role in the survival of these organisms. Besides that, a biobank with bacteria and fungus isolates from LF of Brazilian stingless bees was created, which can be used for different studies and the prospection of biotechnology compounds.

Comparison of the Sensitivity of Tetragonisca angustula (Apidae-Meliponini) and Apis mellifera (Apidae-Apini) to Three Insecticides (Malathion, Imidacloprid, and Fipronil) Used in Costa Rica.

The decline of insect pollinators is a significant concern within the current biodiversity crisis. The paradox between the benefits that these animals represent to humans and the evidence of human activities driving their extinction calls for the urgent protection of bees. To address the role of chemical pollution in this scenario, we assessed the acute toxicity as well as four biomarker responses (cholinesterase [ChE], glutathione S-transferase, catalase, and lipid peroxidation [LPO]) elicited by dietary 24-h exposure to three insecticides (malathion, imidacloprid, and fipronil) on the stingless neotropical bee Tetragonisca angustula and the honeybee Apis mellifera. Malathion was the most toxic substance to both species, with 48-h median lethal doses (LD50s) of 0.25 ng/bee to A. mellifera and 0.02 ng/bee to T. angustula. Fipronil was also highly toxic and presented a similar toxicity to both species, with 48-h LD50s of 0.5 ng/bee (A. mellifera) and 0.4 ng/bee (T. angustula). Imidacloprid had the lowest acute toxicity with a 48-h LD50 of 29 ng/bee for A. mellifera, whereas T. angustula tolerated exposure higher than 35 ng/bee. Apparent biomarker responses were observed in bees of both species that survived exposure to higher concentrations of malathion (ChE inhibition) and fipronil (increased LPO). Our results suggest that specific sensitivity to insecticides varies greatly among compounds and pollinator species, but the use of different representative species can facilitate the prioritization of substances regarding their risk to pollinators. Further research is necessary to better characterize the risk that pesticides represent in neotropical agricultural landscapes. Environ Toxicol Chem 2023;42:1022-1031. © 2023 SETAC.

Nitric Oxide Production in mixed cultures of infected rats with Neospora caninum and treated with Jataí Honey (Tetragonisca angustula)

Neosporosis is a disease caused by Neospora caninum sp (JP Dubey), an intracellular parasite that affects many animal species, fostering abortions and neurological disorders. Recent studies on Neospora caninum have shown that glial cells have been considered a model of in vitro infections of these protozoa. Honey has been used since ancient times for its anti-inflammatory and antimicrobial properties. The present study aimed to evaluate the in vitro reactivity of glial cells (astrocytes and microglia) infected with N. caninum treated with Jataí honey at 1% (Tetragonisca angustula). After 72 hours from infection, mitochondrial metabolism, dehydrogenase lactate activity (LDH), nitric oxide production (NO) and the number of parasites were checked. Cultures treated with honey at 1% have shown mitochondrial metabolism and cell permeability increase. There was an increase in nitrite production, possible indicating a microglial activation. Nitric Oxide values found in this study may indicate an immune response against Neospora caninum tachyzoites, since such increase may contribute to reduce the number of tachyzoites. So, our results suggest that honey had a protective effect over astrocytes and microglia cultures infected with Neospora caninum.

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

BackgroundStingless 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.MethodsLocal 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.ResultsTwelve 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.ConclusionsThe 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.

Melissopalynology of <i>Coffea arabica</i> honey produced by the stingless bee <i>Tetragonisca angustula</i> (Latreille, 1811) from Alajuela, Costa Rica

<abstract> <p><italic>Tetragonisca angustula</italic> is the most widespread stingless bee species, from Mexico to Northern Argentina. It is called Mariola in Costa Rica. Native plant species offering food resources and nesting sites to stingless bees are included in reforestation and conservation programs. In Costa Rica there are continuous initiatives on listing flora supporting meliponiculture. In this study, a sample of pot-honey was collected from sealed honey pots within nests of <italic>Tetragonisca angustula</italic> in Alajuela, Costa Rica. It was acetolyzed following standard methods and the pollen types were visualized by microscopic analysis at 200X magnification using a Nikon Eclipse Ni binocular scope. Electronic brightfield micro-photographs were obtained at 1000X magnification and pollen types were plated. Palynological descriptions were provided for major pollen grains. The botanical identifications of plant families and genera were established by comparison with pollen atlases and were validated consulting the 2022 Tropicos Missouri Botanical Garden database. Seventy-nine pollen types were recognized in the pollen spectrum, representing 36 families and 67 genera of flowering plants. Their habits were trees (51%), lianas/vine (11%), herbs (19%), herb/tree (5%), shrubs (5%), shrub/tree (1%) and not assigned (8%). This assemblage indicated the presence of lowland tropical forest elements, probably small relicts of secondary forest surrounding open and cultivated areas where <italic>Coffea arabica</italic> pollen dominated in the honey pollen spectrum with 54.3% of total counts, with secondary <italic>Paullinia</italic> sp. 8.7%, <italic>Vochysia</italic> sp. 4.8% and <italic>Cassia</italic> sp. 4.2% and 95% of pollen taxa present in < 3% relative frequency. Taxa offering only pollen (polleniferous) were considered honey contaminants (32%) not explaining the nectar botanical origin of honey.</p> </abstract>

Evaluation of the polyphenolic profile of native Ecuadorian stingless bee honeys (Tribe: Meliponini) and their antibiofilm activity on susceptible and multidrug-resistant pathogens: An exploratory analysis

Biofilms are associated with infections that are resistant to conventional therapies, contributing to the antimicrobial resistance crisis. The need for alternative approaches against biofilms is well-known. Although natural products like stingless bee honeys (tribe: Meliponini) constitute an alternative treatment, much is still unknown. Our main goal was to evaluate the antibiofilm activity of stingless bee honey samples against multidrug-resistant (MDR) pathogens through biomass assays, fluorescence (cell count and viability), and scanning electron (structural composition) microscopy. We analyzed thirty-five honey samples at 15% (v/v) produced by ten different stingless bee species (Cephalotrigona sp., Melipona sp., M. cramptoni, M. fuscopilosa, M. grandis, M. indecisa, M. mimetica, M. nigrifacies, Scaptotrigona problanca, and Tetragonisca angustula) from five provinces of Ecuador (Tungurahua, Pastaza, El Oro, Los Ríos, and Loja) against 24-h biofilms of Staphylococcus aureus, Klebsiella pneumoniae, Candida albicans, and Candida tropicalis. The present honey set belonged to our previous study, where the samples were collected in 2018–2019 and their physicochemical parameters, chemical composition, mineral elements, and minimal inhibitory concentration (MIC) were screened. However, the polyphenolic profile and their antibiofilm activity on susceptible and multidrug-resistant pathogens were still unknown. According to polyphenolic profile of the honey samples, significant differences were observed according to their geographical origin in terms of the qualitative profiles. The five best honey samples (OR24.1, LR34, LO40, LO48, and LO53) belonging to S. problanca, Melipona sp., and M. indecisa were selected for further analysis due to their high biomass reduction values, identification of the stingless bee specimens, and previously reported physicochemical parameters. This subset of honey samples showed a range of 63–80% biofilm inhibition through biomass assays. Fluorescence microscopy (FM) analysis evidenced statistical log reduction in the cell count of honey-treated samples in all pathogens (P <0.05), except for S. aureus ATCC 25923. Concerning cell viability, C. tropicalis, K. pneumoniae ATCC 33495, and K. pneumoniae KPC significantly decreased (P <0.01) by 21.67, 25.69, and 45.62%, respectively. Finally, scanning electron microscopy (SEM) analysis demonstrated structural biofilm disruption through cell morphological parameters (such as area, size, and form). In relation to their polyphenolic profile, medioresinol was only found in the honey of Loja, while scopoletin, kaempferol, and quercetin were only identified in honey of Los Rios, and dihydrocaffeic and dihydroxyphenylacetic acids were only detected in honey of El Oro. All the five honey samples showed dihydrocoumaroylhexose, luteolin, and kaempferol rutinoside. To the authors’ best knowledge, this is the first study to analyze stingless bees honey-treated biofilms of susceptible and/or MDR strains of S. aureus, K. pneumoniae, and Candida species.