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Stingless bees (Meliponini) are a monophyletic group of eusocial insects inhabiting tropical and subtropical regions. These insects represent the most abundant and diversified group of corbiculate bees. Meliponini mostly rely on fermentation by symbiont microbes to preserve honey and transform pollen in stored food. Bee nests harbor diverse microbiota that includes bacteria, yeasts, filamentous fungi, and viruses. These microorganisms may interact with the bees through symbiotic relationships, or they may act as food for the insects, or produce biomolecules that aid in the biotransformation of bee products, such as honey and bee bread. Certain microbial species can also produce antimicrobial compounds that inhibit opportunistic bee pathogens.

Products made by bees are well-known for their beneficial properties and nutritional value. This association has been proven by scientific studies that describe their composition and biological activities. The aim of this study is to portray the state of the art on research regarding stingless bee honey. The search for standards that guide the trade of these products is still portrayed as a future perspective, since there are significant differences in relation to honey from Apis mellifera and it often requires additional treatments.

Made available in DSpace on 2020-12-12T01:57:45Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-03-01 National Council for Scientific Research Federal Agency for Scientific Organizations Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Chromoblastomycosis is a neglected disease characterized by cutaneous, subcutaneous or disseminated lesions. It is considered an occupational infectious disease that affects mostly rural workers exposed to contaminated soil and vegetal matter. Lesions mostly arise after a traumatic inoculation of herpotrichiellaceous fungi from the Chaetothyriales order. However, the environmental niche of the agents of the disease remains obscure. Its association with insects has been predicted in a few studies. Therefore, the present work aimed to analyze if social insects, specifically ants, bees, and termites, provide a suitable habitat for the fungi concerned. The mineral oil flotation method was used to isolate the microorganisms. Nine isolates were recovered and phylogenetic analysis identified two strains as potential agents of chromoblastomycosis, i.e., Fonsecaea pedrosoi CMRP 3076, obtained from a termite nest (n = 1) and Rhinocladiella similis CMRP 3079 from an ant exoskeleton (n = 1). In addition, we also identified Fonsecaea brasiliensis CMRP 3445 from termites (n = 1), Exophiala xenobiotica CMRP 3077 from ant exoskeleton (n = 1), Cyphellophoraceae CMRP 3103 from bees (n = 1), Cladosporium sp. CMRP 3119 from bees (n = 1), Hawksworthiomyces sp. CMRP 3102 from termites (n = 1), and Cryptendoxyla sp. from termites (n = 2). The environmental isolate of F. pedrosoi CMRP 3076 was tested in two animal models, Tenebrio molitor and Wistar rat, for its pathogenic potential with fungal retention in T. molitor tissue. In the Wistar rat, the cells resembling muriform cells were observed 30 d after inoculation. Graduate Program in Microbiology Parasitology and Pathology Federal University of Paraná University Center Campo Real Federal University of Paraná Graduate Program in Pharmacology UFPR Medical Department Federal University of Maranhão Embrapa Amazônia Oriental CPATU Westerdijk Fungal Biodiversity Institute Department of Biochemistry and Microbiology Institute of Biological Sciences UNESP-São Paulo State University Division of Microbial Resources CPQBA University of Campinas Center of Expertise in Mycology of Radboud University Medical Center Canisius Wilhelmina Hospital Department of Biochemistry and Microbiology Institute of Biological Sciences UNESP-São Paulo State University CNPq: 312811/2018–7 CAPES: Brazil CAPES: Finance Code 001, Brasilia

Males can control female reproduction using genital plugs to impede access by rivals. In social bees, ants, and wasps, plugging may involve traumatic mating, with females being harmed. In stingless bees, chances are that plugs may promote ovarian activan, and are thought to ensure single mating?a general tendency among the social Hymenoptera. However, understanding on relationships between mating plugs, traumatic mating, and mating systems in stingless bees remains limited. To address this, we (1) compared mated queens of 7 Neotropical species to understand the patterns of copulatory marks in females and (2) compared pre- and post-mating genitalia of males and females in Melipona fasciculata to depict plug functional morphology. Data revealed an unprecedented consequence of mating in stingless bees: the characteristic marks left by mating plugs on female abdomens and the inferences that can be made from them. To our surprise, in 1 species M. fasciculata we found that queens retain the plug long after mating, and may carry it for the rest of their lives. All the other 6 species retained the plug for only a short period. Remated queens were only found in M. seminigra, whose multiple copulatory marks match previous findings of polyandry in this species. Our study shows that queens can remate, and suggests that male genital morphology may determine in part the time persistence of plugs. We conclude that traumatic mating plugs do not fully prevent remating in stingless bees and that mating systems are not uniform in this group. Nonetheless, exceptional cases of facultative polyandry in social insects?for example, when mating plugs fail?may confirm a general tendency for single mating in close link with efficient mating plugs. Made available in DSpace on 2022-03-12T02:25:33Z (GMT). No. of bitstreams: 1 Menezes-Queens-remate-2021.pdf: 832682 bytes, checksum: 5f2af29141433e0774e54690deb690bb (MD5) Previous issue date: 2021

In this study, we investigated the chemical compositions and antioxidant and antimicrobial activities of propolis produced by the stingless bee Frieseomelitta longipes and the honeybee Apis mellifera collected from colonies in North Brazil. In terms of volatile composition, both mono- and sesquiterpenes were detected in the propolis of F. longipes while only sesquiterpenes were detected in that of A. mellifera. Out of 50 volatiles identified in all samples, 26 were found exclusively in F. longipes propolis and 8 were found exclusively in A. mellifera propolis. The chemical profiles of the propolis extracts were determined by atmospheric pressure chemical ionization-mass spectrometry and liquid chromatography-electrospray ionization-tandem mass spectrometry allowed to identify several prenylated benzophenones. A. mellifera extracts exhibited major antioxidant activity as assessed by the 2,2-diphenyl-1-picrylhydrazyl method and all extracts exhibited antioxidant activity as assessed by the β-carotene/linoleic acid method. The ethanolic extracts of the propolis showed promisor activity against all tested microorganisms. Made available in DSpace on 2019-02-15T23:42:42Z (GMT). No. of bitstreams: 1 01004042qn41050485.pdf: 673911 bytes, checksum: 0fa612807ad27c5b53f14b66e2607183 (MD5) Previous issue date: 2019-02-14

Here we describe the life histories of adult males of the the Amazonian stingless bee Melipona flavolineata Friese, commonly known as ?uruçu amarela?. Males reach sexual maturity inside nests, presenting seminal vesicles full of sperm cells and becoming able to fl y at a mean age of 10 and 15 days, respectively. They aggregate twice in their lives, once before leaving the nest, and another at external congregation sites, by using their capacity to reach congregation sites dependent on morphological attributes, such as large eyes and elongated thorax. Furthermore, we describe three atypical phenomena for Meliponini males: M. fl avolineata males have dimorphic color pattern; they lose their genital capsules, even when they fail to copulate; and penisless (sterile) males can stay alive for up to two days. The life history strategies of Meliponini males have only just started to be told and provide many interesting questions for future studies. Made available in DSpace on 2019-02-13T23:44:43Z (GMT). No. of bitstreams: 1 Veigaetal2018.pdf: 743710 bytes, checksum: 9ce0ef38bcbab43cc44bce53cdd1e81a (MD5) Previous issue date: 2019-02-13

Understanding the functional roles of different pollinator species is crucial to the development of sustainable farming practices in pollinator-dependent crops. However, this can be challenging for crop plants in tropical regions with hyper-diverse pollinator communities. Here, we assess pollen loads of different insect visitors to inflorescences of acai palm (Euterpe oleracea), the most important native crop in the Amazon estuary region. Flower-visiting insects were collected from pistillate (female) inflorescences at eight sites, including four managed floodplain forests and four plantations. Pollinator Importance Value Index (PIVI) and Relative Importance (RI) scores were calculated for common visitor taxa (≥ 10 individuals) using sum visit frequencies and median pollen loads. Pollen load analyses revealed that over seventy insect taxa, including bees, flies, beetles, wasps and ants, were effective vectors of E. oleracea pollen. Native bees, including both solitary and eusocial taxa, were the most efficient pollen vectors, with median pollen loads at least eight times higher than those of the next best insect group (flies). Insect pollen loads were at their highest between 0800 and 1300 hours, and four insect taxa had RI scores > 0.05, including two meliponine bees belonging to the Trigona genus (Trigona branneri Cockerell and Trigona pallens Fabricius) and two halictid bee genera (Augochloropsis and Dialictus). Our results suggest that native bees play an important role in acai pollination and should be the primary focus of pollinator management in acai production systems.

The differentiation of workers into morphological castes represents an important evolutionary innovation that is thought to improve division of labor in insect societies. Given the potential benefits of task-related worker differentiation, it is puzzling that physical worker castes, such as soldiers, are extremely rare in social bees and absent in wasps. Following the recent discovery of soldiers in a stingless bee, we studied the occurrence of worker differentiation in 28 stingless bee species from Brazil and found that several species have specialized soldiers for colony defence. Our results reveal that worker differentiation evolved repeatedly during the last ~ 25 million years and coincided with the emergence of parasitic robber bees, a major threat to many stingless bee species. Furthermore, our data suggest that these robbers are a driving force behind the evolution of worker differentiation as targets of robber bees are four times more likely to have nest guards of increased size than non-targets. These findings reveal unexpected diversity in the social organization of stingless bees., Although common in ants and termites, worker differentiation into physical castes is rare in social bees and unknown in wasps. Here, Grüter and colleagues find a guard caste in ten species of stingless bees and show that the evolution of the guard caste is associated with parasitization by robber bees.

Although the importance of bees as the pollinators responsible for maintaining gene flow for many native and cultivated plants in ecosystems around the world is recognized, much of their biodiversity and behavior remains to be discovered. Stingless bees are considered key pollinators for several plant species in tropical and subtropical ecosystems and they also provide pollination services for economically important agricultural crops. Many countries are using the honey bee (Apis mellifera Linnaeus, 1758, Hymenoptera: Apidae) as a surrogate to evaluate the risk of pesticides to all species of bees. However, there is uncertainty regarding the extent to which honey bees can serve as surrogates for non-Apis bee species in the risk assessment for pesticides. This paper provides a short overview of the life history traits relevant in risk assessment of stingless bees. It summarizes what is known about stingless bee exposure to pesticides compared to that of honey bees and presents criteria for potential candidate species from Brazil for use in pesticide risk assessment in tropical environments. This paper also identifies gaps in knowledge of bee biology and pesticide exposure routes not covered by the current honey bee exposure assessment paradigm. Based on these gaps, research is needed on life history traits, estimates of nectar and pollen consumption, mud, resin, and water collection and available protocols to adequately assess toxic effects of pesticides to stingless bees. This review is part of a series of papers on the risk of exposure of non-Apis bees to pesticides.

Different microorganisms are present in pot-pollen and participate in bee bread preparation. During fermentation, vitamins, antimicrobial compounds, and enzymes can be secreted. Spoilage of bee bread is avoided by the low pH of pot-pollen, caused by lactic and acetic acid fermentation and alcoholic fermentation, and by the presence of natural products with antibiotic properties produced by resident microbiota of stored bee pollen. Interactions among microorganisms living in pot-pollen can control and optimize the microbiota, after resistant microorganisms survive in the adverse conditions created by fermentation. Evidence suggests that the symbiotic relationship between bees and pot-pollen microorganisms is stable and that an inoculum can be added by bees to ferment freshly collected and deposited pollen. The quality of pollen selected to prepare bee artificial diets and the addition of fermented pollen as an inoculum to ferment the material augment food in periods of scarcity. Additionally, propagation of plants with different blooming periods, and flowers with abundant pollen, may aid meliponiculture.

The attraction of sexual partners is a vital necessity among insects, and it involves conflict of interests and complex communication systems among male and female. In this study, we investigated the developing of sexual attractiveness in virgin queens (i.e., gynes) of Melipona flavolineata, an eusocial stingless bee. We followed the development of sexual attractiveness in 64 gynes, belonging to seven age classes (0, 3, 6, 9, 15, 18 days post-emergence), and we also evaluated the effect of different social interactions (such as competition between queens and interactions with workers) on the development of attractiveness in other 60 gynes. We used the number of males that tried to mate with a focal gyne as a representative variable of its sexual attractiveness. During the essays, each gyne was individually presented to 10 sexually mature males, and during 3 min, we counted the number of males that everted their genitalia in response to the presence of a gyne. Here, we show that M. flavolineata gynes are capable to (i) maintain their sexual attractiveness for long periods through adult life, (ii) they need a minimum social interaction to trigger the development of sexual attractiveness, and (iii) that gynes express this trait only within a social context. We conclude that the effective occurrence of matings is conditional on potential social interactions that gynes experienced before taking the nuptial flight, when they are still in the nest. These findings bring insights into the factors determining reproductive success in social insects.

International audience; AbstractThe foraging success of a bee species is related to a combination of climatic factors and resource availability. Here, we analyzed how food storage by the stingless bee Scaptotrigona aff. depilis relates to the seasonal variation in floral resources availability in a tropical environment with two well-defined seasons. We found a positive relationship between the amount of food stored and resource availability, suggesting that colonies intensify food collection in the season with higher food availability (rainy season). This ensures the perennial state of stingless bee colonies during the dry season (food scarcity and lower ambient temperatures). Bees collected pollen from at least 60 plant species, but food pots were dominated by just nine plants. Additionally, S. aff depilis attempted to unevenly use the plant species for food storage in the rainy season, which indicates that the colonies maximize their food intake as soon as resources are available.

International audience; AbstractWe studied the relationship between worker longevity and the age of foraging onset in the bee Melipona fasciculata, as well as the longevity oscillation in the rainy and dry seasons. Workers that emerged in the rainy season started to forage later and lived at least 50 % longer than foragers from the dry season. In both periods, a higher longevity was observed in workers that started to forage earlier in life but did not forage all days of their careers. We also showed, by using a Weibull model, that workers experienced higher mortalities at older ages in the rainy season, but the same model did not fit with the data from the dry season. This lack of fit in the dry season can be explained by the high mortality of workers that did not start to forage in this season and to other intrinsic factors of the colonies. Thus, the age of foraging onset and internal colonial factors must be considered in studies examining worker longevity in free-foraging colonies in this diverse group of eusocial bees.

International audience; Stingless bees are a diverse group of highly eusocial tropical bees and potential pollinators of natural and crop environments. Nevertheless, large-scale breeding for agricultural purposes still needs development. A bottleneck is the small number of queens generally found in the colonies of most species. A proposed solution is to develop in vitro rearing of stingless bee queens, which includes a technical support due to the massive liquid feeding of larvae. In this study, we tested the efficacy of in vitro queen-rearing techniques in terms of queen size, survival, and fecundity. We found that humidity must be kept high during the first 6 days of larval development and reduced thereafter to 75 %. In the most effective treatments, we obtained up to 97.9 % queen survival. We also found that queens not different in size from natural queens could be produced if sufficient larval food is provided. In vitro queens were able to mate and lay viable eggs. This methodology is also useful for several research appliances, like pesticide effect on bees, pollen quality effect in caste determination, and the use of genetic sources for selection programs, among others.

The differentiation of workers into morphological subcastes (e.g., soldiers) represents an important evolutionary transition and is thought to improve division of labor in social insects. Soldiers occur in many ant and termite species, where they make up a small proportion of the workforce. A common assumption of worker caste evolution is that soldiers are behavioral specialists. Here, we report the first test of the "rare specialist" hypothesis in a eusocial bee. Colonies of the stingless bee Tetragonisca angustula are defended by a small group of morphologically differentiated soldiers. Contrary to the rare specialist hypothesis, we found that soldiers worked more (+34%-41%) and performed a greater variety of tasks (+23%-34%) than other workers, particularly early in life. Our results suggest a "rare elite" function of soldiers in T. angustula, that is, that they perform a disproportionately large amount of the work. Division of labor was based on a combination of temporal and physical castes, but soldiers transitioned faster from one task to the next. We discuss why the rare specialist assumption might not hold in species with a moderate degree of worker differentiation.

International audience; Like in honey bees, the pollen collected and stored by stingless bees usually undergoes a fermentation process characterized by increase in moisture, lactic acid, and proliferation of microorganisms. We tested whether 2-day-old Scaptotrigona aff. depilis workers were more attracted to and consumed fermented pollen from old pollen pots (>7 days) or fresh pollen collected from the corbicula of foragers. In each bioassay, we offered both types of pollen to 40 inexperienced workers of one colony for 24 min, and repeated the procedure in ten different colonies. In all cases, there were more bees feeding on the fermented pollen, which was 2.2 times more consumed than the fresh pollen. Our results suggested that fermented pollen attracted more bees potentially due to innate preference of young bees, higher levels of attractant substances present in fermented pollen, or due to associative learning reminiscent from larvae feeding habits.

International audience; Most stingless bee species build their nests inside tree hollows. In this paper, we present trap-nest containers which simulate nesting cavities so as to attract swarms of stingless bees. Although regularly used by stingless bee beekeepers in Brazil, this technique to obtain new colonies has not yet been systematically studied. We used two different types of trap-nests (plastic and cardboard) of four different sizes (0.5, 1.0, 2.0, and 3.0 L) containing propolis extract and wax. Over a period of 2 years, 61 swarms of nine different stingless bee species were attracted to the trap-nests. Most swarms chose the largest container (3 L); swarms were collected mostly in springtime (October–December). The plastic containers were more successfully occupied than others by stingless bee swarms. Trap-nests are a viable tool for stingless beekeepers, researchers and conservation biologists to obtain and study stingless bee colonies.

International audience; AbstractIn this study, we investigate the behavioural response of the highly eusocial stingless bee Scaptotrigona depilis to high temperatures. We found that nest temperature in the brood area can be up to 2.5 °C lower relative to a control empty box during hot periods. We showed that high temperatures increase both water collection and wing fanning behaviour at the colony level, suggesting that these behaviours are adaptations to cooling the nest in this species. Additionally, we measured survival and development time of pupae incubated at five different constant temperatures (22, 26, 30, 34 and 38 °C). We found that the development time of S. depilis brood significantly varied between treatments and had a strong negative correlation with temperature. Brood survived over a large range of incubation temperatures; however, extreme temperatures (22 and 38 °C) were almost 100 % lethal, highlighting the importance of thermoregulation, at least in extreme conditions.

Stingless bees are highly eusocial bees, and are characterised by having perennial colonies that are typically headed by one single-mated queen (Peters et al., 1999). The main exception to this pattern is found in Melipona bicolor, which is the only stingless bee species discovered so far to exhibit facultative polygyny, whereby several queens may coexist and share reproduction inside the colony for considerable periods of time (Bego, 1989; Velthuis et al., 2006). Aside from that, there are, for a few stingless bee species, also some anecdotal reports of temporary, transient episodes of polygyny (e.g. in M. scutellaris, Carvalho-Zilse and Kerr, 2004; Plebeia droryana, Silva, 1972; and P. wittmanni, Witter and Wittmann, 1997), which are usually associated with queen replacement events. Here we report on a novel case of occasional polygyny in the stingless bee M. quadrifasciata, in which an exceptionally high number (8) of egg-laying queens were found to coexist inside the same colony. In addition, and in contrast to some of the earlier studies demonstrating occasional polygyny in stingless bees, which were purely based on observations, we provide the first genetic data about the reproductive partitioning and relatedness among these different queens. ispartof: Apidologie vol:42 issue:2 pages:211-213 status: published

International audience; Worker body size is a key feature for stingless bee biology, being related with the foraging range of colonies. We correlated the intertegular span, corbicular area, head width, and interocular distance, as well as the fresh weight, from workers of Melipona flavolineata, a species from the Amazonian Region, with the stored reserves of honey and pollen. The food reserves decreased with the increase of rainfall, and there was a significant correlation between intertegular span, corbicular area, and food stores. The corbiculae was inversely correlated with food reserves, while the width of thorax was positively related. We consider the allometric variation of thorax width and corbicular area as a mechanism to adjust colonial food collection, since larger corbiculae would maximize the pollen-gathering during the rainy, dearth periods, and when the resource supply increases, the workers increase in the width of thorax, being able to explore larger areas and replenish the colonial food stores.