Stingless bees (Apidae: Meliponini) are common visitors to flowering plants in the tropics, but evidence for their importance and effectiveness as crop pollinators is lacking for most plant species. They are known to visit the flowers of approximately 90 crop species. They were confirmed to be effective and important pollinators of 9 species. They may make a contribution to the pollination of approximately 60 other species, but there is insufficient information to determine their overall effectiveness or importance. They have been recorded from another 20 crops, but other evidence suggests that they do not have an important role because these plants are pollinated by other means. The strengths and limitations of stingless bees as crop pollinators are discussed. Aspects of their biology that impact on their potential for crop pollination are reviewed, including generalized flower visiting behavior of colonies, floral constancy of individual bees, flight range, and the importance of natural vegetation for maintaining local populations.

Stingless bees are social bees that live in tropical and subtropical areas of the world. All species produce honey, which has been appreciated by humans since ancient times. Here, the general panorama of meliponiculture is presented. Deforestation and poor management are the main problems faced by this incipient industry. For a profitable meliponiculture, much more biological information is needed, as well as field studies in natural conditions. In the near future, we suggest that the successful use of these pollinators will promote the development of new breeding techniques and commercialization possibilities, which must be designed to be sustainable.

Keywords: Invasive species Ecosystem function Insect pests Invasive plants Ecological restoration Biological control Natural ecosystems a b s t r a c tOf the 70 cases of classical biological control for the protection of nature found in our review, there were fewer projects against insect targets (21) than against invasive plants (49), in part, because many insect biological control projects were carried out against agricultural pests, while nearly all projects against plants targeted invasive plants in natural ecosystems. Of 21 insect projects, 81% (17) provided benefits to protection of biodiversity, while 48% (10) protected products harvested from natural systems, and 5% (1) preserved ecosystem services, with many projects contributing to more than one goal. In contrast, of the 49 projects against invasive plants, 98% (48) provided benefits to protection of biodiversity, while 47% (23) protected products, and 25% (12) preserved ecosystem services, again with many projects contributing to several goals. We classified projects into complete control (pest generally no longer important), partial control (control in some areas but not others), and ''in progress," for projects in development for which outcomes do not yet exist. For insects, of the 21 projects discussed, 62% (13) achieved complete control of the target pest, 19% (4) provided partial control, and 43% (9) are still in progress. By comparison, of the 49 invasive plant projects considered, 27% (13) achieved complete control, while 33% (16) provided partial control, and 49% (24) are still in progress. For both categories of pests, some projects' success ratings were scored twice when results varied by region. We found approximately twice as many projects directed against invasive plants than insects and that protection of biodiversity was the most frequent benefit of both insect and plant projects. Ecosystem service protection was provided in the fewest cases by either insect or plant biological control agents, but was more likely to be provided by projects directed against invasive plants, likely because of the strong effects plants exert on landscapes. Rates of complete success appeared to be higher for insect than plant targets (62% vs 27%), perhaps because most often herbivores gradually weaken, rather than outright kill, their hosts, which is not the case for natural enemies directed against pest insects. For both insect and plant biological control, nearly half of all projects reviewed were listed as currently in progress, suggesting that the use of biological control for the protection of wildlands is currently very active.

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Increasing human land use for agriculture and housing leads to the loss of natural habitat and to widespread declines in wild bees. Bee foraging dynamics and fitness depend on the availability of resources in the surrounding landscape, but how precisely landscape related resource differences affect bee foraging patterns remains unclear. To investigate how landscape and its interaction with season and weather drive foraging and resource intake in social bees, we experimentally compared foraging activity, the allocation of foragers to different resources (pollen, nectar, and resin) and overall resource intake in the Australian stingless bee Tetragonula carbonaria (Apidae, Meliponini). Bee colonies were monitored in different seasons over two years. We compared foraging patterns and resource intake between the bees' natural habitat (forests) and two landscapes differently altered by humans (suburban gardens and agricultural macadamia plantations). We found foraging activity as well as pollen and nectar forager numbers to be highest in suburban gardens, intermediate in forests and low in plantations. Foraging patterns further differed between seasons, but seasonal variations strongly differed between landscapes. Sugar and pollen intake was low in plantations, but contrary with our predictions, it was even higher in gardens than in forests. In contrast, resin intake was similar across landscapes. Consequently, differences in resource availability between natural and altered landscapes strongly affect foraging patterns and thus resource intake in social bees. While agricultural monocultures largely reduce foraging success, suburban gardens can increase resource intake well above rates found in natural habitats of bees, indicating that human activities can both decrease and increase the availability of resources in a landscape and thus reduce or enhance bee fitness.

Aims: The aim of this study was to determine the spectrum of antimicrobial activity of 11 samples of stingless bee honey compared to medicinal, table and artificial honeys. Methods and Results: Activity was assessed by agar diffusion, agar dilution, broth microdilution and time-kill viability assays. By agar dilution, minimum inhibitory concentration (MIC) ranges were 4% to >10% (w ⁄ v) for Gram-positive bacteria, 6% to >16% (w ⁄ v) for Gram-negative bacteria and 6% to >10% (w ⁄ v) for Candida spp. By broth microdilution, all organisms with the exception of Candida albicans and Candida glabrata were inhibited at £32% (w ⁄ v). Geometric MIC (w ⁄ v) means for stingless bee honeys ranged from 7AE1% to 16AE0% and were 11AE7% for medicinal honey and 26AE5% for table honey. Treatment of organisms with 20% (w ⁄ v) stingless bee honey for 60 min resulted in decreases of 1-3 log for Staphylococcus aureus, >3 log for Pseudomonas aeruginosa and <1 log for C. albicans. Similar treatment with each control honey resulted in decreases of <1 log for all organisms. Conclusions: Stingless bee honey has broad-spectrum antibacterial activity although activity against Candida was limited. Stingless bee honey samples varied in activity and the basis for this remains to be determined. Significance and Impact of the Study: Stingless bee honey had similar activity to medicinal honey and may therefore have a role as a medicinal agent.

Stingless bees (Tribe Meliponini) are a diverse group of highly eusocial bees distributed throughout the tropics and subtropics. Trigona carbonaria honey, from Australia, was characterized by traditional physicochemical parameters (acidity, sugars, diastase, electrical conductivity, hydroxymethylfurfural, invertase, nitrogen, and water content) and other compositional factors (flavonoids, polyphenols, organic acids, and water activity), as well as total antioxidant capacity and radical scavenging activity. For the Australian T. carbonaria, the traditional analytical parameters were similar to those previously reported for neotropical stingless bee honey and confirm that honeys produced by Meliponini bees possess several physicochemical properties that are distinctly different from Apis mellifera honey, with higher values of moisture (26.5 +/- 0.8 g of water/100 g of honey), water activity (0.74 +/- 0.01), electrical conductivity (1.64 +/- 0.12 mS/cm), and free acidity (124.2 +/- 22.9 mEq/kg of honey) and a very low diastase activity (0.4 +/- 0.5 diastase number) and invertase activity (5.7 +/- 1.5 invertase number). The sugar spectrum was quite different from that of A. mellifera honey, with 20.3 +/- 2.9 g of maltose/100 g of honey. The values of pH (4.0 +/- 0.1), lactonic acidity (4.7 +/- 0.8 mEq/kg of honey), sucrose (1.8 +/- 0.4 g/100 g of honey), and fructose/glucose ratio (1.42 +/- 0.13) fell in the same ranges as those of A. mellifera honey. Citric (0.23 +/- 0.09) and malic (0.12 +/- 0.03) acid concentrations (in g/kg of honey) of T. carbonaria honeys were in the range described for A. mellifera honey. D-Gluconic was more concentrated (9.9 +/- 1.3 g/kg of honey), in the range of Italian Castanea, Thymus, Arbutus, and honeydew honeys. Flavonoid content was 10.02 +/- 1.59 mg of quercetin equivalents/100 g of honey, and polyphenol contents were 55.74 +/- 6.11 mg of gallic acid equivalents/100 g of honey. The antioxidant activity, expressed as percentage of 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) cation (ABTS(*+)) decolorization, was 233.96 +/- 50.95 microM Trolox equivalents, and free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH(*)) depletion was 48.03 +/- 12.58 equivalents of ascorbic acid. All reported values are averages +/- standard deviation. The antioxidant activity can represent an important added value for T. carbonaria honey, to initiate a medicinal approach for both nutritional and pharmaceutical applications, besides further physicochemical characterization.

The interaction between flowers and insect pollinators is an important aspect of the reproductive mechanisms of many plant species. Several laboratory and field studies indicate that raising flower temperature above ambient can be an advantage in attracting pollinators. Here we demonstrate that this preference for warmer flowers is, in fact, context-dependent. Using an Australian native bee as a model, we demonstrate for the first time a significant shift in behaviour when the ambient temperature reaches 34°C, at which point bees prefer ambient temperature nectar over warmer nectar. We then use thermal imaging techniques to show warmer nectar maintains the flight temperature of bees during the period of rest on flowers at lower ambient temperatures but the behavioural switch is associated with the body temperature rising above that maintained during flight. These findings suggest that flower-pollinator interactions are dependent upon ambient temperature and may therefore alter in different thermal environments.