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

2017 ◽  
Vol 70 (4) ◽  
Author(s):  
Ernest Stawiarz ◽  
Beata Żuraw ◽  
Agnieszka Marut

<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>

2021 ◽  
Vol 12 (2) ◽  
pp. 621-632
Author(s):  
Roberto Quintero Domínguez ◽  
Lino De la Cruz Larios ◽  
Diego Raymundo González Eguiarte ◽  
José Arturo Solís Magallanes ◽  
José Francisco Santana Michel ◽  
...  

This study examines the different plants visited by the honeybee (Apis mellifera L.) during the honey harvest season (August to November) 2012. The work consisted in identifying the corbicular pollen pellets collected by the bees in one apiary in the village of Huejotitan, municipality of Jocotepec, state of Jalisco, Mexico. Three hives were selected and sampled monthly by means of Ontario modified pollen traps. The samples were tagged and frozen and later processed by acetolysis technique to remove the exine; permanent glycerine slides were made for the preservation and analysis. Identification and counting of pollen grains was performed using an Olympus BH-2® upright microscope equipped with a 100X ocular micrometer to measure each individual species pollen grain, using immersion oil. Wild plants in bloom were also collected monthly, tagged, pressed and taken to the herbarium for identification; the pollen was extracted, processed and identified for a reference collection that served as an ancillary means of identification and as a seasonal reference to the blooming species. In the corbicular pollen, 23 types of plants were identified: 13 at species level, five at genus level and five at family level belonging to 17 plant families. Myrtaceae resulted the most frequently represented family followed by Asteraceae, Fabaceae and Lamiaceae.


Osmia ◽  
2009 ◽  
Vol 3 ◽  
pp. 23-27
Author(s):  
Maryse Vanderplanck ◽  
Étienne Bruneau ◽  
Denis Michez

Oligolectism and phenological shift between host plant and pollinator: study of two psammophilic spring species, Colletes cunicularius (L.) (Hymenoptera, Colletidae) and Andrena vaga (Panzer) (Hymenoptera, Andrenidae). - Colletes cunicularius (L.) and Andrena vaga (Panzer), both vernal solitary ground nesting bees, have been reported to feed strictly on Salix (Salicaceae) (oligolectic behavior). However a recent study has shown that Colletes cunicularius is able to shift on different plants, at least in the studied sites in Germany. In this study we investigated the extent to which this behavior applies to other regions within the distribution range of these bee species. We analysed the host-plant association of two populations in Belgium. Pollen loads and brood cells of both species have been investigated by optical microscopic analysis to estimate the proportion of willow pollen. Andrena vaga females collect pollen only on Salix but pollen loads of Colletes cunicularius sometimes contain other pollen types in agreement with a previously study. It is observed that the first nest cells made by C. cunicularius in early spring contain exclusively willow pollen. Towards the end of willow blooming, Colletes cunicularius females change their floral choice by foraging on other pollen types.


HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1127B-1127
Author(s):  
Patricio A. Brevis ◽  
D. Scott NeSmith

Blueberries are bee-pollinated species that benefit from cross-pollination. Cross-pollination is particularly critical for optimum fruit set of rabbiteye blueberries (Vaccinium ashei Reade) because of their limited degree of self-fertility. In order to determine if the failure to set adequate commercial fruit loads is due to a lack of cross-pollination, research was needed to establish how much out-crossing rabbiteye blueberry pollinators actually do. A novel method was developed to identify pollen grains on the bodies of bumblebees by cultivar. The technique discriminates between two cultivars, based on differences in pollen diameter. Bumblebees were collected in a plot composed of blueberry plants of the cultivars Brightwell and Climax since these cultivars produce pollen of different size. Pollen loads of bumblebees contained low proportions of cross-pollen regardless of the cultivar they were visiting. Data suggest that inadequate levels of cross-pollination play a major role in low fruit set problems of rabbiteye blueberry. The composition of bees' pollen load changed with the phenology of the crop. The greatest likelihood for cross-pollination occurred around the time of maximum bloom overlap. Bumblebees foraging on `Brightwell' flowers carried more total blueberry pollen and a higher proportion of self-pollen than those visiting `Climax'. This may be due to differences in pollen release between flowers of these two cultivars.


2021 ◽  
Author(s):  
Samuel Monnier ◽  
Michel Thibaudon ◽  
Jean-Pierre Besancenot ◽  
Charlotte Sindt ◽  
Gilles Oliver

&lt;p&gt;Knowledge:&lt;/p&gt;&lt;p&gt;Rising CO2 levels and climate change may be resulting in some shift in the geographical range of certain plant species, as well as in increased rate of photosynthesis. Many plants respond accordingly with increased growth and reproduction and possibly greater pollen yields, that could affect allergic diseases among other things.&lt;/p&gt;&lt;p&gt;The aim of this study is the evolution of aerobiological measurements in France for 25-30 years. This allows to follow the main phenological parameters in connection with the pollination and the ensuing allergy risk.&lt;/p&gt;&lt;p&gt;Material and method:&lt;/p&gt;&lt;p&gt;The RNSA (French Aerobiology Network) has pollen background-traps located in more than 60 towns throughout France. These traps are volumetric Hirst models making it possible to obtain impacted strips for microscopic analysis by trained operators. The main taxa studied here are birch, grasses and ragweed for a long period of more than 25 years over some cities of France.&lt;/p&gt;&lt;p&gt;Results:&lt;/p&gt;&lt;p&gt;Concerning birch but also other catkins or buds&amp;#8217; trees pollinating in late winter or spring, it can be seen an overall advance of the pollen season start date until 2004 and then a progressive delay, the current date being nearly the same as it was 20 years ago, and an increasing trend in the quantities of pollen emitted.&lt;/p&gt;&lt;p&gt;For grasses and ragweed, we only found a few minor changes in the start date but a longer duration of the pollen season.&lt;/p&gt;&lt;p&gt;Discussion:&lt;/p&gt;&lt;p&gt;As regards the trees, the start date of the new production of catkins or buds is never the 1&lt;sup&gt;st&lt;/sup&gt; of January but depends on the species. For example, it is early July for birch. For breaking dormancy, flowering, and pollinating, the trees and other perennial species need a period of accumulation of cold degrees (Chilling) and later an accumulation of warm degrees (Forcing). With climate change these periods may be shorter or longer depending of the autumn and winter temperature. Therefore, a change in the annual temperature may have a direct effect on the vegetal physiology and hence on pollen release. It may also explain why the quantities of pollen produced are increasing.&lt;/p&gt;&lt;p&gt;The Poaceae reserve, from one place to another and without any spatial structuring, very contrasted patterns which make it impossible to identify a general tendency. This is probably due to the great diversity of taxa grouped under the generic term Poaceae, which are clearly not equally sensitive to climate change.&lt;/p&gt;&lt;p&gt;Conclusion:&lt;/p&gt;&lt;p&gt;Trees with allergenic pollen blowing late winter or early spring pollinate since 2004 later and produce amounts of pollen constantly increasing. Grasses and ragweed have longer periods of pollination with either slightly higher or most often lower pollen production.&lt;/p&gt;


2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Midori Kobayashi-Kidokoro ◽  
Seigo Higashi

The food habits of the solitary beeCeratina flavipeswere studied by observation on foraging behavior and identifying the pollen grains that they collected. It appeared thatC. flavipestend to collect pollen from particular species; however, they visit multiple flowering species. We analyzed pollen sources from pollen loads of dried specimens from single foraging trips (SFT) and in pollen balls created from a single foraging day (SD). The pollen from all pollen balls in a nest represented the harvest from an entire breeding season (BP). This analysis showed that each bee on average collected pollen from 3.24 (SFTs), 2.02 (SD), and 3.12 (BP) flowering species. Bees collected pollen from a total of 14 flowering plant species. Furthermore, we calculated when pollen balls were created and found no significant interaction between seasonal pollen availability and bee preferences. Moreover, bees had consistent flower preferences, even if the preferred flower was not dominant at all times. These results indicate thatC. flavipesexhibits flower constancy, and therefore, the generalist pollinatorC. flavipescould function like a specialist pollinator.


2020 ◽  
Vol 126 (3) ◽  
pp. 377-386 ◽  
Author(s):  
Nicola Delnevo ◽  
Eddie J van Etten ◽  
Nicola Clemente ◽  
Luna Fogu ◽  
Evelina Pavarani ◽  
...  

Abstract Background and Aims Ant–plant associations are widely diverse and distributed throughout the world, leading to antagonistic and/or mutualistic interactions. Ant pollination is a rare mutualistic association and reports of ants as effective pollinators are limited to a few studies. Conospermum (Proteaceae) is an insect-pollinated genus well represented in the south-western Australia biodiversity hotspot, and here we aimed to evaluate the role of ants as pollinators of C. undulatum. Methods Pollen germination after contact with several species of ants and bees was tested for C. undulatum and five co-flowering species for comparison. We then sampled the pollen load of floral visitors of C. undulatum to assess whether ants carried a pollen load sufficient to enable pollination. Lastly, we performed exclusion treatments to assess the relative effect of flying- and non-flying-invertebrate floral visitors on the reproduction of C. undulatum. For this, we measured the seed set under different conditions: ants exclusion, flying-insects exclusion and control. Key Results Pollen of C. undulatum, along with the other Conospermum species, had a germination rate after contact with ants of ~80 % which did not differ from the effect of bees; in contrast, the other plant species tested showed a drop in the germination rate to ~10 % following ant treatments. Although ants were generalist visitors, they carried a pollen load with 68–86 % of suitable grains. Moreover, ants significantly contributed to the seed set of C. undulatum. Conclusions Our study highlights the complexity of ant–flower interactions and suggests that generalizations neglecting the importance of ants as pollinators cannot be made. Conospermum undulatum has evolved pollen with resistance to the negative effect of ant secretions on pollen grains, with ants providing effective pollination services to this threatened species.


2008 ◽  
Vol 24 (05) ◽  
pp. 477-484 ◽  
Author(s):  
Tuanjit Srithongchuay ◽  
Sara Bumrungsri ◽  
Ekapong Sripao-raya

Abstract:Although plant species that attract multiple species of pollinators predominate in tropical plant communities, pollination specialists appear to be at a greater advantage in tropical ecosystems in which pollinators are numerous and many plants flower synchronously. The present study determined the breeding system and legitimate pollinators ofOroxylum indicumVent. in Songkhla and Patthalung Provinces, Thailand.Oroxylum indicumexhibits steady-state flowering, with one or two flowers per inflorescence opening each night. Flowers open in the evening and drop off shortly after midnight, while its bilabiate stigma is highly sensitive, and quickly close upon being touched.Oroxylum indicumis self-incompatible. Hand-cross pollination and open pollination yielded the highest pollination success (47.7% and 31.2% respectively, n = 7 trees). About 900 pollen grains are needed for initiating fruit set. It is confirmed that a fruit bat,Eonycteris spelaea, is the legitimate pollinator. Bats are responsible for all pollen load and the pollen load from only one visit is generally sufficient to initiate fruit set. AlthoughEonycteris spelaeais effective, it is an inefficient pollinator. Compared with plant species pollinated by multiple animal species, the likelihood of pollination failure resulting from the decline in populations ofEonycteris spelaeawill be much more intense inOroxylum indicum.


1989 ◽  
Vol 237 (1287) ◽  
pp. 133-173 ◽  

The framework is developed for a formal quantitative analysis of the vegetative dynamics of Trifolium repens , based on partitioning the components of its growth. The method is used to describe the vegetative dynamics of T. repens in one pasture during the course of one year. Seasonal and spatial variation were analysed by regression on several environmental variables. The present paper includes only a partial analysis, covering the dynamics of leaves and nodes per shoot axis. The remainder of the analysis will be presented in subsequent papers. The production of modules per shoot axis, and the subsequent mortality of leaves, and burial and mortality of nodes, showed different patterns of spatial and seasonal variability, and different types of response to the environment. There was much seasonal and little spatial variation in rates of birth, burial and death of leaves and nodes. In contrast, there was relatively little seasonal and much spatial variation in the numbers of leaves and nodes, even though these numbers are determined by present and past births and deaths. The rate of production of leaves by individual apices varied from 0.01 per day to 0.19 per day. It appeared to be determined largely by temperature, probably of the apex, but also to some extent by genotype. Leaves survived for 1-21 weeks. The risk of leaf mortality varied with the age of the leaf, the number of sheep in the field, and the season. Leaves born in November tended to live longest, and those born in summer with many sheep shortest. At least 56% of leaves were utilized by sheep, the remainder dying from other causes. Seasonal fluctuations in death rate of leaves tended to lag three weeks behind fluctuations in birth rate, but with additional fluctuations caused by changes in grazing. The lag caused there to be a minimum of 1-5 leaves per axis in January, and a maximum of 3-12 in August, although at all times the number of leaves was increasing on some axes and decreasing on others. Axes were progressively buried by worm casts and leaf litter within 0-39 weeks of birth. The rate of burial appeared to be determined largely by earthworm activity and by treading by sheep. In autumn and early spring, nodes and internodes were buried faster than new ones were born. As a result, as few as three internodes were exposed on average in March, compared with a maximum mean of 20 in August. By late winter, some axes were entirely buried and started to grow vertically upwards towards the soil surface. Nodes survived for 14-85 weeks, the mean longevity being 51 weeks. On average, each axis bore 25 nodes, with a range of 10-49 nodes. Seasonal fluctuations in death rate lagged some 4-8 weeks behind those in birth rate. Survivial of nodes and internodes was dependent on the establishment and survival of roots. When the oldest rooted node on an axis died, all of the axis between it and the next rooted node also died. The development of pseudo-taproots increased the longevity of nodes by 100 days. Leaves had much shorter lives than their nodes. The ‘average’ shoot axis bore 3.5 nodes with leaves, 4.2 nodes still visible but without leaves, and 17.6 nodes buried beneath worm casts and litter.


2019 ◽  
Vol 23 (5-6) ◽  
pp. 803-817 ◽  
Author(s):  
Rosi Rollings ◽  
Dave Goulson

Abstract There is great interest in planting urban areas to benefit pollinating insects, with the potential that urban areas and gardens could act as an extensive network of pollinator-friendly habitats. However, there are a great many different plant cultivars available to the gardener, and a paucity of evidence-based advice as to which plants are truly most attractive to flower-visiting insects. Here, we report insect visitation to metre square plots of 111 different ornamental plant cultivars at a site in central UK. Data were collected over 5 years, and comprise over 9000 insect observations, which were identified to species (for honeybees and bumblebees) or as ‘solitary bees’, Syrphidae, Lepidoptera and ‘others’. Unlike some previous studies, we found no difference in numbers of insects attracted to native or non-native species, or according to whether plants were annuals, biennials or perennials, but we did find that native plants attracted a significantly higher diversity of flower-visiting insects. Overall, the most-visited plants were Calamintha nepeta, Helenium autumnale and Geranium rozanne. However, patterns of visitation were quite different for every insect taxa examined. For example, different species of short-tongued bumblebees showed little overlap in their most-preferred plant cultivars. Interestingly, very similar plant cultivars often attracted different insect communities; for example, 72% of visitors to Aster novi belgii were honeybees or bumblebees, while the related Anthemis tinctoria, which also has daisy-like flowers, did not attract a single honeybee or bumblebee but was popular with solitary bees, hoverflies, and ‘other’ pollinators. Some plant cultivars such as Eryngium planum and Myosotis arvensis were attractive to a broad range of insects, while others attracted only a few species but sometimes in large numbers, such as Veronicastrum virginicum and Helenium autumnale which were both visited predominantly by honey bees. It is clear that we do not yet fully understand what factors drive insect flower preferences. Recommendations are made as to which flower cultivars could be combined to provide forage for a diversity of pollinator groups over the season from early spring to autumn, though it must be born in mind that some plants are likely to perform differently when grown in different environmental conditions.


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