Important Pollen Sources Research Articles

Foraging distances, habitat preferences and seasonal colony performance of honeybees in Central European forest landscapes

Abstract Unmanaged forest is considered as native habitat of the Western honeybee Apis mellifera and is assumed to provide important pollen and nectar sources. However, resource supply might be spatially and temporally restricted in managed forests and landscape‐scale studies in European forest regions are currently lacking. Capitalizing on a unique communication behaviour, the waggle dance, we investigated honeybee foraging in a deciduous forest region in southern Germany. We analysed 2022 waggle dances performed by bees of 12 colonies placed in the centre of landscapes with varying degree of forest cover (50%–99% at a 2‐km radius) from March to August 2019, thereby identifying foraging distances and habitat preferences over almost an entire foraging season. By connecting dance information with colony weight recordings, we assessed the role of landscape composition and the contribution of different habitat types to colony weight gain. Foraging distances generally increased with the amount of forest in the surrounding landscape pointing to inferior food resources in the forest. Yet, this effect strongly depended on the season and was more pronounced for pollen than for nectar foraging. Even though colonies in forest‐dominated landscapes had to fly further, colony weight was not significantly affected by forest cover. Compared to expectations based on the proportions of different habitats, colonies foraged more frequently in grassland and cropland than in deciduous and coniferous forests, with late summer being an especially difficult period for pollen foraging in forests. During a phase of colony weight gain in early summer, the use of forests for nectar/honeydew foraging was close to the expectation, highlighting forests as an important complementary source of carbohydrates during short periods of the year. Policy implication. The ecological and economic value of managed forest as habitat for honeybees could be significantly increased by the continuous provision of floral resources, especially for pollen foraging. Therefore, we recommend diversifying forest stands with insect‐pollinated trees, permitting secondary successions in forest gaps, and at larger scales, creating forest landscapes with high habitat diversity. This will not only help native, wild‐living honeybees and beekeepers' colonies residing in forest areas but will also foster social bees in general.

The Impact of Willow Flowering Time on Species Composition and the Number of <i>Apoidea</i> Pollinators

Pollinators are important to wild and cultivated plants, and the same plants are important to pollinators as well. A very important source of pollen and nectar to pollinators are willows (Salix spp.). The aim of this study was to demonstrate which Apoidea species are attracted by a species-diverse willow plantation (Poznan University of Life Sciences Willow Collection, Poland), the proportion of the number of honeybees to other species from the Apoidea superfamily visiting willow plantations, and whether the flowering date of male and female willow individuals affect the species composition and number of pollinators. Observations of willow phenology were carried out in the second year of willow growth, from March 9 to December 7, 2012. The insects were observed between April 6 and May 11, 2012. The results of this study showed 30 Apoidea species. Among 1591 Apoidea individuals, only 17 honeybee individuals were noted. The results show that the willow pollen production optimum occurred when the minimum air temperatures stopped dropping below zero. This parameter and this period are also related to the intensification of the occurrence of the noted insects. It can also be concluded that the pollen production season precedes the flowering optimum of female flowers and that the optimum flowering of female flowers is correlated with a significant increase in air temperature.

Pollen Spectrum and Foraging Plants for the Red Dwarf Bee in Jordan

Pollen spectrum of honey, and pollen content of the honey sac of the red dwarf honeybee (Apis florea F.), which was discovered recently in Jordan, were studied. Pollen diversity and pollen density in these samples, which were collected from two sites in Jordan, were investigated. A total of 4399 pollen grains were counted and classified in the honey of A. florea. 2667 pollen grains, or 60.63% of total pollen, were obtained from Centaurea hylolepis Bioss., which is considered to be the Dominant Pollen (DP), and the studied honey was monofloral. About 1541 pollen grains, or 35.03% of the total, were collected from Family Caryophyllacea and considered to be a Secondary Pollen (SP) source. Cardania draba (L.) was considered a Minor Pollen (MP) source with 2.07% abundance, followed by Ecualyptus sp. (0.68%); Acacia cyanophylla Lindl. (0.59%); Leopoldia desirticola (Rech.f.) Feinbrun (0.48%); Salvia lonigera Poir. (0.39%); and Sambucus racemosa L. (0.14%). The plant diversity or number of plant species foraged by small bees was eight. While the plant diversity in honey sac content of the small bee from another site, El-Akaba, was nine. Centaurea sp., Echinops sp. and Erodium sp. were considered as Secondary Pollen (SP) sources, with percent abundances of 33.99, 23.60% and 16.23%, respectively. The following Important Minor Pollen sources (IMP) and their (abundance %) and classification were as follows: Asphodelus sp. (6.96%); Phoenix sp. (5.94%); and Rubus sp. (5.66%). Minor Pollen (MP) sources were: Diplotaxis sp. (1.6%); Ecobllium sp. (1.16%) and Sencio sp. (0.16%).

Terminalia arjuna: An Important Subsistence Pollen Source for Apis florea During Spring Season in Southern West Bengal

Terminalia arjuna (Roxb.) Wight & Arn., a large evergreen tree, shows massive flowering during spring season (March–April). The floral characteristics with deep seated nectar having high sugar concentration serve this plant as an important pollen and nectar source for Apis bees. The inflorescences with clusters of flowers of this plant provide an excellent platform for foraging by Apis florea Fabr. In spite of diverse angiospermic flora in the present study area, A. florea intends to forage this handsome evergreen taxon because of its nutritious pollen and highest percentage of nectar sugar concentration. In the present article, pollen analysis of eight spring honey samples from different regions of Purulia district of West Bengal reveals that T. arjuna is found to be the predominant pollen type. So, a mutualistic relationship has been established between A. florea and T. arjuna. This plant taxon serves as a key nectar source for A. florea and takes the advantage of its highly nutritious pollen grains for increasing the colony and its strong nectar flow for honey production during the spring season in this southern part of Bengal. A. florea also foraged other angiospermic taxa such as Pedilanthus tithymaloides L., Croton bonplandianum Baill., Citrus, Solanum, Albizia lebbeck (L.) Benth., Semecarpus anacardium L., Flacourtia jamgomas Lour., Psidium guajava L., Borassus flabellifer L., Tamarindus indica L., Lannea coromandelica (Houtt.) Merr. and Asteraceae.

Nesting biology and flower preferences of Megachile (Sayapis) zaptlana

Megachile zaptlana is a solitary cavity-nesting leafcutter bee widely distributed in Brazil. Using two models of trap nests in sugarcane monoculture and agroecosystem environments in Pernambuco, northeastern Brazil, we studied the nesting biology of this species. We obtained 193 nests, 39.4% in the monoculture and 60.6% in the polyculture site. The nests consisted of a linear series of brood cells coated with a mixture of chewed leaves with sand, often followed by a long empty vestibular cell and an operculum at the entrance. A nest contained on average 2.4 (± 1.3) brood cells. Emergence patterns indicate that the species has a multivoltine life cycle without diapause and a peak emergence in the drier months from October to December. The sex ratio females: males, was 1:0.43. Females founded their nests in holes with diameters of 5–10 mm, with a preference for 6 mm (68%). Pollen analysis of larval diet showed that the species is polylectic, and brood cells contained pollen from 19 plant species, especially from the families Asteraceae, Rubiaceae, Plantaginaceae, and Fabaceae. In the studied agroecosystems, ruderal plants were the most important nectar and pollen sources for Megachile zaptlana. Given that Megachile zaptlana is polylectic and multivoltine, it might be a good candidate for future use as a managed pollinator.

How do sunflower pollen mixtures affect survival of queenless microcolonies of bumblebees (Bombus impatiens)?

The high pollen and nectar yield of Asteraceae flowers combined with the abundance and diversity of these plants should make them an important pollen source for both specialist and generalist bees. However, studies have found Asteraceae pollen to be a poor diet for some generalist bees, possibly owing to nutrient deficiencies or the presence of secondary metabolites or digestive barriers that prevent nutrient assimilation. Mixing pollens could allow bees to exploit these unfavourable pollens, if the different pollen sources help to complement nutrient deficiencies or alleviate the effects of toxic secondary metabolites. In our study, we examined how the proportion of sunflower (Helianthus annuus, Asteraceae) pollen in the diet of captive-reared bumblebees (Bombus impatiens) affects the survival of bees in queenless microcolonies. Bees fed on sunflower pollen had significantly shorter lifespans than bees fed on broad bean (Vicia faba, Fabaceae), rapeseed (Brassica napus, Brassicaceae) or Cucurbitaceae pollen. However, survival on mixed pollen diets containing 50% sunflower pollen was as great as that on non-sunflower diets, which suggests that the other pollens were able to compensate for the low nutritive quality of the sunflower pollen. Due to agricultural intensification and a loss of wildflowers, farmland monocultures (e.g. sunflower crops) can be important floral resources for bumblebees. Our study suggests that providing alternative floral resources of high nutritive quality could help mitigate the potential harmful effects of a monofloral sunflower diet on bumblebees.

Floral sources used by the orchid bee Euglossa cordata (Linnaeus, 1758) (Apidae: Euglossini) in an urban area of south-eastern Brazil

Although orchid bees (Apidae: Euglossini) are known as key pollinators in tropical ecosystems, knowledge of their floral sources is still scarce, especially for those species commonly found in urban environments. We aimed to identify the pollen, nectar and resin sources used by the widespread species Euglossa cordata in an urban area in south-eastern Brazil. The residual pollen from 81 brood cells of nine nests reactivated between October 2013 and December 2014 was acetolysed and analysed. A total of 50 pollen types belonging to 20 botanical families were identified in the samples. Pollen sources included species from seven families; five of them were plants with poricidal anthers (Bixaceae, Commelinaceae, Fabaceae, Melastomataceae and Solanaceae). The mass-flowering trees Handroanthus chrysotrichus and H. heptaphyllus (Bignoniaceae) are firstly reported as important pollen sources to an orchid bee species. Nectar was collected primarily from plants with long, tubular corolla as Acanthaceae, Apocynaceae, Bignoniaceae and Convolvulaceae. The vine species Dalechampia stipulacea (Euphorbiaceae) acted as a floral resin source. All pollen sources consisted of native plants whereas some exotic plant species were visited for nectar collection. Although nesting in an area encompassed by a high proportion of invasive plant species, Euglossa cordata females preferred to visit native plants to gather floral resources.

General characteristics of airborne pollen in Montevideo city, Uruguay.

: This paper analyses daily and seasonal variations on pollen concentrations and the influence of meteorological conditions on the airborne pollen from June 2011 to May 2014. Data is also compared with results from a previous pollen survey from 2000-2001. Ninety-three taxa were identified, belonging to 49 trees and shrub taxa and 44 herbaceous taxa. The most important pollen sources were Poaceae, Platanus, Cupressaceae/Taxaceae, Eupatorieae type, Celtis, Urticaceae, Myrtaceae, Casuarina, Amaranthaceae, Cyperaceae, Fraxinus, Arecaceae, Ricinus communis, Moraceae, Myrsine, Ambrosia, Quercus, and Pinaceae. Pollen was recorded all year round but the main pollen season was from August to April. Inter-annual differences were observed on pollen indexes, dates and values of daily peak concentrations and monthly accumulated concentrations. Temperature, relative air humidity and wind speed and direction seem to be the most influential meteorological variables on pollen concentrations. The number of days that pollen concentrations are above moderate and high thresholds levels is estimated and woody and non-woody pollen concentrations would be above moderate levels on average 182 days per year.

Pollen sources in the Bojanów forest complex identified on honeybee pollen load by microscopic analysis

<p>The aim of this study was to determine sources of pollen for the honeybee in the Bojanów forest complex, Nowa Dęba Forest District (southeastern Poland). Sampling of pollen loads from bees extended from the beginning of May until the end of September 2016 and was carried out at 7-day intervals using pollen traps mounted at the entrance of beehives. A total of 73 pollen load samples were collected from the study area.</p><p>Fifty-nine taxa from 31 plant families were identified in the analyzed material. From 4 to 21 taxa (average 9.5) were recorded in one sample. The pollen of Brassicaceae (“others”), <em>Taraxacum</em> type, <em>Solidago</em> type, and <em>Rumex</em> had the highest frequency in the pollen loads examined. Apart from these four taxa, pollen grains of <em>Rubus</em> type, Poaceae (“others”), <em>Calluna</em>, <em>Fagopyrum</em>, <em>Trifolium repens</em> s. l., <em>Phacelia</em>, <em>Aster</em> type, <em>Melampyrum</em>, <em>Quercus</em>, <em>Cornus</em>, and <em>Veronica</em> were recorded in the dominant pollen group. The forest habitat taxa that provided pollen rewards to honeybees in the Bojanów forest complex were the following: <em>Rubus</em>, <em>Calluna</em>, <em>Prunus</em>, <em>Tilia</em>, <em>Frangula alnus</em>, <em>Pinus</em>, <em>Quercus</em>, <em>Cornus</em>, <em>Robinia pseudoacacia</em>, <em>Salix</em>, and <em>Vaccinium</em>. Apart from forest vegetation, the species from meadows and wastelands adjacent to this forest complex, represented by <em>Taraxacum</em>, <em>Rumex</em>, <em>Plantago</em>, Poaceae, <em>Trifolium repens</em>, and <em>Solidago</em>, proved to be an important source of pollen. The study indicates that forest communities are a valuable source of pollen for pollinating insects from early spring through to late fall.</p>

Phosphorus Deposition in a Low-Phosphorus Landscape: Sources, Accuracy and Contribution to Declines in Surface Water P

Atmospheric deposition can be an important source of phosphorus (P) to watersheds in geologically low-P landscapes like the Precambrian Shield, in south-central Ontario. Recent observations in this region of declining total P (TP) concentrations in streams and lakes, as well as P limitation in vegetation, prompted this investigation into the potential contributing role of atmospheric deposition. Long-term (1980–2014) measurements of bulk TP deposition at four monitoring stations, as well as wet-only deposition at one of the sites (2012–2014) and pollen measurements in 2014, were used to assess the potential contribution of biogenic sources to TP deposition in the region. Ratios of phosphorus to potassium (P:K) in historical bulk deposition and variability in P deposition among the four sites indicated that continuously open, bulk deposition collectors are enriched in ‘local’ biogenic sources of P, particularly in the summer, fall and spring months. Furthermore, in 2014 pollen could account for as much as 30% of bulk TP deposition, and pine trees (Pinus strobus) were the most important source of pollen (>75% of collected pollen). In contrast, winter bulk deposition was the least affected by local, biogenic sources, and likely best reflects net P inputs to this region from long-range (that is, external to the watershed) sources. Catchment input–output budgets for P that use measured annual bulk deposition totals as inputs are generally strongly positive (indicating net retention/accumulation of P within watersheds), whereas annual budgets calculated using extrapolated winter deposition are in approximate balance. Balanced P budgets are more consistent with regional observations of declining surface water TP and P limitation in terrestrial vegetation. Importantly, there was no significant decline in winter TP deposition over the period of record (1980–2014), which suggests that changes in regional deposition are not responsible for declines in surface water TP. Although we recommend extrapolating winter bulk deposition measurements to approximate annual atmospheric TP input to terrestrial ecosystems in non-dusty, oligotrophic landscapes such as this, local sources of P, particularly pollen, are likely important seasonal sources of P nutrition to lakes.

Nutritional value of bee-collected pollens of hardy kiwi, Actinidia arguta (Actinidiaceae) and oak, Quercus sp. (Fagaceae)

Bee-collected pollens have gained attention as natural dietary supplement for human nutrition over the honeybee feed, and become important commercial hive products for beekeepers. Oak trees, Quercus sp. (Family: Fagaceae) and hardy kiwi, Actinidia arguta (Family: Actinidiaceae) are important pollen sources for honey bees. During collection and storage through the addition of nectar and salivary secretions the chemical composition of pollen is changed. We analyzed nutrient contents of bee collected oak and hardy kiwi pollens and compared with recommended requirement of essential amino acids for honey bee brood development. The results revealed that protein content was found 23.2% for oak and 26.5% for hardy kiwi pollen. All the determined essential amino acid contents of both oak and kiwi pollen satisfied the minimum individual amino acid requirement of honey bee. Threonine was present in marginal level in hardy kiwi pollen. Fat content of oak and hardy kiwi pollen were found 7 and 4.5% respectively. The higher value of polyunsaturated fatty acid/saturated fatty acid - stearic acid, lower AI and TI value, presence of essential fatty acid n-3 linolenic acid indicated these pollens as superior sources of fat. The most abundant mineral was found potassium in both the pollens followed by phosphorus. In contrast sodium content was found very less. In vitro digestibility of oak and kiwi pollen were found 69.5 and 37.8% suggesting the difficulty of nutrient uptake directly from pollen grains.

Trophic-niche of the Leaf Cutter BeeMegachile(Moureapis)maculata(Hymenoptera: Megachilidae) in Southeastern Brazil

ABSTRACT: According to their trophic-niche breadth, bees can be classified as polylectic if they collect pollen from a wide variety of plant species or oligolectic if they obtain pollen from only a few species which usually belong to the same genus or even family. In this study, we measured the trophic-niche of Megachile maculata as well as its breadth in southeastern Brazil. Samples of pollen from nests were used to identify the plants visited by this bee. We found 11 different pollen grain types. Asteraceae occurred at high frequency (97.36%); 84.09% belonged to Baccharis and 12.31% to the genus Vernonia. Trophic-niche breadth of M. maculata varied little over the study period. The highest trophic-niche breadth was found at the end of the dry season and the lowest in November, at the beginning of the rainy season. We concluded that M. maculata is an oligolectic species and Baccharis and Vernonia are important pollen sources.

How landscape, pollen intake and pollen quality affect colony growth in Bombus terrestris

Abundance and diversity of bumblebees have been declining over the past decades. To successfully conserve bumblebee populations, we need to understand how landscape characteristics affect the quantity and quality of floral resources collected by colonies and subsequently colony performance. We therefore investigated how amount and composition of pollen collected by buff-tailed bumblebee Bombus terrestris colonies was affected by the surrounding landscape (i.e. the proportion of forest, urban, semi-natural habitats) and how they were related to colony growth. Thirty B. terrestris colonies were placed at grassland sites differing in surrounding landscape. Colonies were established in spring when availability of flowering plants was highest, and their weight gain was monitored for 1 month. We additionally recorded the quantity and compared plant taxonomic composition and nutritional quality (i.e. amino acid composition) of pollen stored. Bumblebee colonies varied little in the pollen spectra collected despite differences in surrounding landscape composition. They collected on average 80 % of pollen from woody plants, with 34 % belonging to the genus Acer. Early colony growth positively correlated with total amount of woody pollen and protein collected and decreased with increasing proportions of semi-natural habitats and total amino acid concentrations. Our results suggest that woody plant species represent highly important pollen sources for the generalist forager B. terrestris early in the season. We further show that colony growth of B. terrestris is predominantly affected by the quantity, not quality, of forage, indicating that several abundant plant species flowering throughout the bumblebees’ foraging season may cover the colonies’ nutritional needs.

Flowering phenology and potential pollen emission of three Artemisia species in relation to airborne pollen data in Poznań (Western Poland).

Artemisia pollen is an important allergen in Europe. In Poznań (Western Poland), three Artemisia species, A. vulgaris, A. campestris and A. absinthium, are widely distributed. However, the contributions of these species to the total airborne pollen are unknown. The aim of the study was to determine the flowering phenology and pollen production of the three abovementioned species and to construct a model of potential Artemisia pollen emission in the study area. Phenological observations were conducted in 2012 at six sites in Poznań using a BBCH phenological scale. Pollen production was estimated by counting the pollen grains per flower and recalculating the totals per inflorescence, plant and population in the study area. Airborne pollen concentrations were obtained using a Hirst-type volumetric trap located in the study area. Artemisia vulgaris began to flower the earliest, followed by A. absinthium and then A. campestris. The flowering of A. vulgaris corresponded to the first peak in the airborne pollen level, and the flowering of A. campestris coincided with the second pollen peak. The highest amounts of pollen per single plant were produced by A. vulgaris and A. absinthium. A. campestris produced considerably less pollen, however, due to its common occurrence, it contributed markedly (30 %) to the summation of total of recorded pollen. A. vulgaris is the most important pollen source in Poznań, but the roles of two other Artemisia species cannot be ignored. In particular, A. campestris should be considered as an important pollen contributor and likely might be one of the main causes of allergic reactions during late summer.

Pollen types used by Centris (Hemisiella) tarsata Smith (1874) (Hymenoptera, Apidae) in the provisioning of brood cells in an area of Caatinga

The aim of this study was to identify, by sediment pollen analysis, the plant species used as floral resources for the provisioning of brood cells in Centris (Hemisiella) tarsata, in an area of Caatinga, within the municipality of Nova Soure, Bahia State, Brazil. The analysis of pollen contents from three brood cells revealed 11 pollen types, corresponding to four botanical families. Malpighiaceae was represented most, followed by Leguminosae, Ochnaceae, and Solanaceae, the latter two represented by just a single pollen type each. On the basis of the percentages in the samples, it was possible to infer that C. tarsata visited distinct plants, but intensified its pollen collection in species related to Aeschynomene martii and Solanum paniculatum pollen types, which are considered the most important pollen sources in the larval diet of this bee. In addition to the pollen sources, we have also recorded seven pollen types regarded as oil ones, all related to the Malpighiaceae family. The information about the resources for C. tarsata can be of great relevance, in view of the importance of these bees in the pollination of native flora.

Assessment of the pollen diet in a wood-dwelling augochlorine bee (Halictidae) using different approaches

Most studies on bee pollen diet are based on the abundance of each pollen type composing honey or pollen stores of whole nests (pollen counts). In an effort to characterize the diet of the augochlorine bee Augochlora amphitrite, we employed nest and intra-nest pollen analyses and bee flower visitation. In addition, we tested a novel approach, the index of relative importance (IRI), a method that combines pollen counts, pollen volume, and frequency of pollen occurrence. Using nest pollen analysis, we found that the Ludwigia type dominated pollen counts, comprising 56 % of whole nests, and thus would have concluded that this is the only most important pollen source in the diet. Instead, we found seven other important sources including Ipomoea alba, Ipomoea cairica, Gymnocoronis spilanthoides, and Pavonia types as well as 26 new floral hosts using all four methods in combination. Thus, we recommend that other studies of bee diet include these other approaches when possible and, especially, the novel approach of IRI.

Urban ragweed populations in vacant lots: An ecological perspective on management

Ragweed (Ambrosia artemisiifolia L.) is one of the most prolific producers of allergenic pollen in North America, and negatively impacts tens of millions of people each year. Recent work shows that local plant populations can be the most important source of allergenic pollen in the urban environment. This research emphasizes that management choices that influence species abundance can determine the burden of allergenic pollen for people living near these plant populations. In Detroit, MI, USA, ragweed populations are predominantly found in vacant lots; the management of these lots could therefore have large impacts on allergenic pollen burdens. The main form of management in these vacant lots is mowing, which occurs at frequencies ranging from monthly mowing to no mowing. We hypothesized that annual or biennial mowing would result in conditions where ragweed populations could thrive. To test this, we conducted a vegetation survey of vacant lots in Detroit, in which we quantified the mowing regime, characteristics of the vegetation, and ragweed presence and stem density. We found that ragweed was significantly more likely to be present in lots that were mowed annually or biennially; unfortunately these are the most common management types, accounting for 51% of vacant lots in Detroit. Ragweed's association with this disturbance regime fits with its early successional status, as it is most competitive in recently disturbed soils where there is reduced competition for resources such as light. We therefore recommend one of two alternative management regimes for reducing ragweed in vacant lots: either mow them frequently (multiple times a growing season) or do not mow them at all. Both approaches will reduce ragweed prevalence in vacant lots and reduce allergenic pollen exposure for people who live near vacant lots.

Cannabis sativa-An Important Subsistence Pollen Source for Apis mellifera.

Cannabis sativa is an important source of pollen for Apis mellifera during the period of floral scarcity (May and June) when major flora is absent. Foraging of bees on the herb under experiment took place during morning and evening hours, while during rest of the day activity remained totally ceased. All the Foraging bees were pollen gatherers as the plant provides pollen only. Maximum foraging took place during morning, however pollen was also collected thoroughly by specific sweeping activity and scrabbling behaviour during evening hours. Foraging frequency of bees was more during morning as compared to that at evening. Average pollen load observed was 4mg/bee. Abundance, Foraging behaviour and pollen loads indicated that this annual herb in good source of pollen during dearth period in summer.

Floral preferences and climate influence in nectar and pollen foraging by Melipona rufiventris Lepeletier (Hymenoptera: Meliponini) in Ubatuba, São Paulo state, Brazil

We describe the environment effects on the amount and quality of resources collected by Melipona rufiventris Lepeletier in the Atlantic Forest at Ubatuba city, São Paulo state, Brazil (44º48'W, 23º22'S). Bees carrying pollen and/or nectar were captured at nest entrances during 5 min every hour, from sunrise to sunset, once a month. Pollen loads were counted and saved for acetolysis. Nectar was collected, the volume was determined and the total dissolved solids were determined by refractometer. Air temperature, relative humidity and light intensity were also registered. The number of pollen loads reached its maximum value between 70% and 90% of relative humidity and 18ºC and 23ºC; for nectar loads this range was broader, 50-90% and 20-30ºC. The number of pollen loads increased as relative humidity rose (rs = 0.401; P < 0.01) and high temperatures had a strong negative influence on the number of pollen loads collected (rs = -0.228; P < 0.01). The number of nectar loads positively correlated with temperature (rs = 0.244; P < 0.01) and light intensity (rs = 0.414; P < 0.01). The percentage of total dissolved solids (TDS) on nectar loads positively correlated with temperature and light intensity (rs = 0.361; P < 0.01 and rs = 0.245; P < 0.01), negatively correlated with relative humidity (rs = -0.629; P < 0.01), and it increased along the day. Most nectar loads had TDS between 11% and 30%, with an average of 24.7%. The volume measures did not show any pattern. Important pollen sources were Sapindaceae, Anacardiaceae, Rubiaceae, Arecaceae, Solanaceae and Myrtaceae; nectar sources were Sapindaceae, Fabaceae, Rubiaceae, Arecaceae and Solanaceae.

Botanical profile of bee pollen from the southern coastal region of Bahia, Brazil

This paper aims to identify the botanical origin of pollen loads collected by Apis mellifera L. in Canavieiras municipality, Bahia state. It provides a list of polliniferous plant species from the Atlantic Forest biome that are important for the development of regional apiculture. Using the acetolysis method, 35 bee-pollen samples were analyzed qualitatively and quantitatively. Results showed that pollen types Elaeis (23.99%), Mimosa pudica (22.78%) and Cecropia (13.68%) were the most abundant among the samples. These also showed the highest relative frequencies of the material studied and were important pollen sources for bees in the study area.