Pollen Species Research Articles

Insect venom allergies-What will change in times of global change?

In Germany, honeybees (Apis mellifera) and various Vespula species (wasps) are primarily relevant for hypersensitivity reactions to stings. Hornets (Vespa crabro), bumblebees, paper wasps (Polistes) and yellowjackets (Dolichovespula) less frequently cause sting reactions. What effects do intensive agricultural utilization and climate change have on the living conditions and occurrence of Hymenoptera and what consequences do they have for the diagnostics and treatment of hypersensitivity reactions to Hymenoptera stings. A literature search was carried out. Honeybees and wild bees are endangered due to introduced diseases, invasive species and pesticides. The aim of widespread beekeeping activity is to protect honeybees, which is why no reduction in stings is to be expected despite increased bee mortality. In Germany, there is evidence of the spread of thermophilic Polistes species (paper wasps) from south to north and the immigration of Vespa velutina nigrithorax (Asian hornet). It is unlikely that these species will lead to asignificant increase in sting reactions. Nests of the red fire ant (Solenopsis invicta), which was originally common in South America, were first detected in Sicily in 2022. Red fire ants are aggressive insects with ahigh potential for adverse sting reactions. Invasive insects must be considered as a trigger in the anamnesis and diagnostics. Diagnostics are only available for the detection of Polistes sensitization. Therapeutic allergens can be obtained from other European countries for venom immunotherapy of a Polistes allergy. Due to cross-reactivity, diagnostic and therapeutic allergens from Vespula spp. are used for the diagnosis and treatment of suspected allergies to the Asian hornet.

Nutritional profiling of common eastern North American pollen species with implications for bee diet and pollinator health

Nutritional profiling of common eastern North American pollen species with implications for bee diet and pollinator health

Biostratigraphy of Late Holocene bottom sediments from the Northern part of Chukchi Sea

The research goal is the investigation of environmental processes of recent sedimentation in the Arctic Ocean area. A short core (length – 37 cm) was taken from the Northern part of the Chukchi Sea. Analytical methods included macroscopic sedimentological description by smear-slides, dating by γ-measurements of 137Cs and 210Pb, diatom and palynological analyses. Sedimentation rates at the research site have been determined to be 1 mm y-1. Thus, the age of the cored sediments spans approximately 400 years, which includes the period of the Little Ice Age. Abundant cold-water diatom species and spores of terrestrial plants within the lower part of the sediment core are characteristic for cold climate conditions, which dominated the Little Ice Age. The occurrence of Jurassic, Cretaceous, and Neogene species of spores and pollen in the Holocene deposits are the evidence of coastal abrasion and the subsequent transfer of the material to the coring site by currents. Southern, subtropical, and tropical species of diatoms within the upper, more recent part of the core reveal the transfer of material by currents from the Pacific Ocean to the Arctic Ocean through the Bering Strait. The results of biostratigraphic analyses indicate environmental changes during the last 400 years, revealed in bottom sediments of the Northern part of the Chukchi Sea.

Main Airborne Pollen Species and Characteristics of Allergic Rhinitis Patients with Pollen-Related Allergies in 13 Northern Chinese Cities.

Pollen allergies have a high prevalence in northern China, whereas, the types of pollen allergens and population characteristics among different regions remain unclear. To study the species and temporal distribution of the main allergenic pollen, as well as the characteristics of patients with pollen-related allergic rhinitis (AR) in different cities in northern China. Pollen data were obtained from pollen-monitoring stations in 13 cities of northern China between 2020 and 2021. Questionnaire surveys and allergen testing were conducted in 494 patients with pollen-related allergies from Beijing in Central, Shenyang in Northeast, and Xi'an in Northwest China. In 13 cities of northern China, the main sources of pollen were cypress, poplar, elm, pine, birch and ash in spring, and mugwort, goosefoot, hop and ragweed in autumn. In Northwest China, the spring and autumn pollen periods started earlier and lasted longer than that in Central and Northeast China, and the pollen counts in autumn in was significantly higher than that in Central and Northeast China. Furthermore, the nasal, ocular and respiratory symptom and quality of life scores of AR patients in Northwest China were significantly higher than that in Central and Northeast China. 69.32-73.28% of patients had annual cost of anti-allergic medication between 500-5000 yuan. However, 40.93-48.86% of patients reported minor control of symptoms. Our results can be used as a basis for developing effective prevention and management measures for patients with pollen-related allergy in these regions, including timely pollen monitoring, patient guidance on protective measures, early intervention, and specific immunotherapy, to improve pollen-related allergy management.

A fluorescence approach for an online measurement technique of atmospheric microplastics.

Microplastic particles in the atmosphere are regularly detected in urban areas as well as in very remote locations. Yet the sources, chemical transformation, transport, and abundance of airborne microplastics still remain largely unexplained. Therefore, their impact on health, weather and climate related processes lacks comprehensive understanding. Single particle detection presents a substantial challenge due to its time-consuming process and is conducted solely offline. To get more information about the distribution, fluxes and sources of microplastics in the atmosphere, a reliable and fast online measurement technique is of utmost importance. Here we demonstrate the use of the autofluorescence of microplastic particles for their online detection with a high sensitivity towards different widely used polymers. We deploy online, single particle fluorescence spectroscopy with a Wideband Integrated Bioaerosol Sensor WIBS 5/NEO (Droplet Measurement Technologies, USA), which enables single particle fluorescence measurements at two excitation wavelengths (280 nm and 370 nm) and in two emission windows (310-400 nm and 420-650 nm). We investigated shredded (<100 μm) everyday plastic products (drinking bottles and yogurt cups) and pure powders of polyethylene terephthalate (PET), polyethylene and polypropylene. For the broad range of typical plastic products analyzed, we detected fluorescence on a single particle level using the WIBS. The online detection can identify particles smaller than 2 μm. In the case of microplastic particles from a PET bottle, 1.2 μm sized particles can be detected with 95% efficiency. Comparison with biological aerosols reveals that microplastics can be distinguished from two abundant pollen species and investigation of the complete fluorescence excitation emission maps of all samples shows that online identification of microplastics might be possible with fluorescence techniques if multiple channels are available.

Marmara Adasında Bulunan Bal Arılarının (Apis mellifera L.) Polen Tercihleri

Islands have a special importance in terms of biodiversity. At the same time, it is important to follow the feeding behavior of pollinators that ensure the continuation of biodiversity throughout the island. In this study, it was aimed to follow the pollen collection activities of honey bees (Apis mellifera L.) on Marmara Island and to determine the pollen sources. Pollen sampling was carried out weekly during the 14 weeks from the first week of April to the first week of July when honey bees intensively carried out pollen collection activities. The sampled pollen grains were classified according to their color and examined by light microscopy. A total of 34 taxa were identified from the pollen grains. The taxa represented in significant proportions were; Rosaceae, Fabaceae, and Centaurea, Ericaceae, Brassicaceae, Cistus, Helianthemum, Vitis and Salix. They constitute a total of 79.37%. Rosaceae family pollen has been found as the most preferred taxa by honey bees for 8 weeks. The first two weeks of May was the most productive period in terms of pollen species in Marmara Island and the amount of pollen brought to the hives decreased in early July. In this study, it was tried to shed light on the pollen collection preferences of honey bees and pollination periods of honey bee used plants under conditions of Marmara Island.

Association between air pollution and emergency room admission for eye diseases in Rome, Italy: A time-series analysis

Eye diseases impose a significant burden on health services due to high case numbers. However, exposure to outdoor air pollution is seldom mentioned as potential harmful factor. We conducted a time-series analysis in Rome, Italy, to estimate the association between daily mean concentration of NO2, PM10 and PM2.5 and daily number of emergency room (ER) admissions for a selected cluster of eye diseases from 2006 to 2016. We used Poisson regression adjusted for time trend, population decrease during summer vacations and holidays, day of week, apparent temperature (hot and cold) and daily concentration of nine pollen species. We observed 581,868 ER admissions during the study period. 44.74% of cases were observed in subjects with less than 20 years, 19.50% in 51–65 age category and 13.4% among children (0–14 years). No differences between sexes were recorded.Mean values of pollutant concentrations were 54.75, 31.01 and 18.14 μg/m3 for NO2, PM10 and PM2.5 respectively. The air temperature ranged from −1 °C to 32.5 °C, with a mean value of 16 °C (SD = 6.88). The apparent temperature spaced from −3.58 °C to 34.08 °C (mean = 15.61 °C, SD = 8.5).The highest percent risk increases for 10 μg/m3 increases of the three pollutants were observed at lag0-1 day (1.3%, 0.63–1.98 for PM2.5; 1.03%, 0.56–1.51 for PM10 and 0.6%, 0.13–1.07 for NO2). Risk increased significantly also at lag0 and lag0-5 day for each pollutant. Secondary analyses showed higher effects in the elderly compared to younger subjects. No differences emerged between sexes. The dose response analysis suggested of possible effects on ER admission risk also at low-level concentrations of PM2.5. A strong confounding effect of pollen was not detected. Resultsof this study are coherent with previous analyses. Speculation can be done about the biological mechanisms that link air pollution to eye damage.

Effects of airborne pollen on allergic rhinitis and asthma across different age groups in Beijing, China

In the context of global warming and rapid urbanization, pollen has become a significant public health concern for Chinese citizens. However, there is a paucity of epidemiological research on the impact of pollen on allergen-linked diseases, such as allergic rhinitis and asthma, in China. Using data from the Beijing Chaoyang Hospital between 2013 and 2019, which included allergic rhinitis and asthma incidence, meteorological records, and air pollution data, we employed a Generalized Additive Model (GAM) to examine the relationship between overall and type-specific pollen concentrations in relation to varying population exposures. We found that increased overall pollen concentrations significantly increased the risks of allergic rhinitis and asthma in diverse populations. Notably, the risk of allergic rhinitis was higher than that of asthma at equivalent pollen concentrations. Seasonal trends indicated that spring pollen peaks, primarily from trees, were associated with a lower risk of both allergic rhinitis and asthma than autumn peaks, predominantly from weeds. This study underscores the importance of identifying pollen species that pose heightened risks to different demographic groups across seasons, thereby providing targeted interventions for public health agencies.

Palynostratigraphy and palaeoenvironment of the Danian sediments from the Nsukka Formation of the Anambra Basin at the vicinity of Ikpankwu, southeastern Nigeria.

Detailed investigations of biostratigraphy of the Nsukka Formation in the Ikpankwu area are paramount due to the fluctuation of depositional environment, fossil flora abundance and diversity interchange, and lateral facies change dynamics from the southern to northern sections of this formation. The microflora assemblages, chronostratigraphic age and depositional paleoenvironment of index palynomorphs suggest a Danian age for the studied strata, based on global dinoflagellate cyst events. The persistent abundance of monocolpate assemblages and the biostratigraphic resolution attained, suggest that the studied sediment interval is continuous. The marker species of terrestrial microflora (Constructipollenites ineffectus, Echitriporites trianguliformis, Foveotriletes margaritae, Longapertites group, Proxapertites group, Retidiporites magdalenensis, Scabratriporites annellus, Spinizonocolpites group, Syncolporites marginatus) and dinocysts (Carpatella cornuta, Danea californica, Fibrocysta licia, Kenleyia pachycerata, Spiniferella cornuta subsp. kasira), compared with several reference sections from the tropical to subtropical province, engineered a refined geologic age and paleoenvironment of deposition of the sediments. These dinocysts taxa are global Danian index fossils which are valuable in the identification of earliest Palaeocene sequence of the formation. The depositional paleoenvironment alternately fluctuates from continental setting to marginal marine inner neritic and outer neritic conditions, based on the presence of land-derived miospores and dinocysts. These macroenvironments are the products of effective vacillating depositional environment systems between the lower and upper deltaic plains, oscillating from tidal flat, lagoon, tidal bar to nearshore open marine influenced settings. Lycopodiaceae-Zlivisporis blanensis fern spore with fragile perispore substantiate the autochtonous vegetation and least transport and palynomorph hydrodynamic system inherent in the predominant pollen and spore species and close proximity to fresh water settings visible in medium to coarse grained sandstone units of the middle section. These microenvironment syntheses of the Nsukka Formation revealed a confirmed and pronounced transgressive systems tract (TST), articulated in the shale sample from the Ikpankwu section of the Nsukka Formation, Anambra Basin. The palaeoenvironments and palynostratigraphic dynamics illustrate that overall progradation was trailed by sporadic retrogradation of the delta with a high biostratigraphic resolution system indicative of continuous biological imprints of the terrestrial and marine microflora of the Nsukka Formation during the Danian.

Fantastic beasts and where to find them: updated Elasmus polistis Burks, 1971 (Hymenoptera: Eulophidae) hosts list and new host genus record

ABSTRACT Given the important ecological role played by social wasps and the fact that parasitism is the main cause of mortality in the early stages of development of these wasps, it is of paramount importance to understand the ecological relationships between hosts and parasitoids. Therefore, the present study presents information on the sex ratio of Elasmus polistis for four Neotropical social wasps hosts, an update list of sixteen known host species of this parasitoid with geographic distribution. These results contributed for to two new Polistes species hosts, and for the first time in colonies of the genus Mischocyttarus.

Differentiating between Monofloral Portuguese Bee Pollens Using Phenolic and Volatile Profiles and Their Impact on Bioactive Properties.

Nowadays, bee products are commended by consumers for their medicinal and dietary properties. This study aimed to differentiate between monofloral bee pollens originating from Portugal using phenolic and volatile profiles and investigate their antioxidant and cytotoxic activity. Total phenolic and flavonoid compounds were recorded between 2.9-35.8 mg GAE/g and 0.7-4.8 mg QE/g, respectively. The LC/DAD/ESI-MSn analytical results allowed us to identify and quantify a total of 72 compounds, including phenolic and phenylamide compounds, whereas GC-MS results revealed the presence of 49 different compounds, mostly ketones, aldehydes, esters, hydrocarbons, and terpenes. The highest DPPH• radical scavenging activity, EC50: 0.07 mg/mL, was recorded in the sample dominated by Castanae sp. pollen, whereas the Rubus sp. (1.59 mM Trolox/mg) and Cistaceae sp. (0.09 mg GAE/g) pollen species exhibited the highest antioxidant activity in ABTS•+ and reducing power assays, respectively. Regarding the anti-carcinogenic activity, only Carduus sp. showed remarkable cytotoxic potential against MCF-7.

Acoustic levitation of pollen and visualisation of hygroscopic behaviour

Abstract. Pollen are hygroscopic; therefore, they have the potential to act as cloud condensation nuclei (CCN) in the atmosphere. This could have uncertain implications for cloud processes and climate as well as plant biodiversity and human health. Previous studies have investigated the hygroscopic swelling of pollen, linked to CCN activity by the κ-Köhler theory, using methods that follow observed mass increase by electrodynamic balance (EDB) or vapour sorption analyser. This study uses an acoustic levitator to levitate pollen grains in the true aerosol phase and uses a macroscope to image the pollen to investigate hygroscopic behaviour when relative humidity (RH) is changed. Two pollen species were studied in this work: Lilium orientalis (oriental lily) and Populus deltoides (eastern cottonwood). Both species were successfully levitated; however, the smaller Populus deltoides showed greater instability throughout experiments. The quality of images taken by the macroscope, and thus calculations of pollen area and aspect ratio, varied significantly and were sensitive to lighting conditions as well as to levitated pollen grain movement and orientation. Experiments with surface-fixed pollen grains were also conducted. They showed evidence that pollen hygroscopic swelling could be observed by the macroscope. The produced results were comparable with previously reported mass increase values. Although less accurate than methods that measure mass changes, the acoustic levitator and macroscope set-up offer an attractive alternative by virtue of being commercial, off-the-shelf, low-cost, and versatile techniques. A key advantage of this method is that it is possible to visually observe particle shape dynamics under varying environmental conditions.

The value of twinned pollinator-pollen metabarcoding: bumblebee pollination service is weakly partitioned within a UK grassland community

Predicting ecological impact of declining bumblebee (Bombus) populations requires better understanding of interactions between pollinator partitioning of floral resources and plant partitioning of pollinator resources. Here, we combine Cytochrome Oxidase 1 (CO1) barcoding for bumblebee identification and rbcL metabarcoding of pollen carried by bees in three species-rich UK pastures. CO1 barcoding assigned 272 bees to eight species, with 33 individuals belonging to the cryptic Bombus lucorum complex (16 B. lucorum and 17 B. cryptarum). Seasonal bias in capture rates varied by species, with B. pratorum found exclusively in June/July and B. pascuorum more abundant in August. Pollen metabarcoding coupled with PERMANOVA and NMDS analyses revealed all bees carried several local pollen species and evidence of pollen resource partitioning between some species pairings, with Bombus pratorum carrying the most divergent pollen load. There was no evidence of resource partitioning between the two cryptic species present, but significantly divergent capture rates concorded with previous suggestions of separation on the basis of foraging behaviour being shaped by local/temporal differences in climatic conditions. Considering the bee carriage profile of pollen species revealed no significant difference between the nine most widely carried plant species. However, there was a sharp, tipping point change in community pollen carriage across all three sites that occurred during the transition between late July and early August. This transition resulted in a strong divergence in community pollen carriage between the two seasonal periods in both years. We conclude that the combined use of pollen and bee barcoding offers several benefits for further study of plant-pollinator interactions at the landscape scale.

Interaction between Air Pollutants and Pollen Grains: Effects on Public and Occupational Health

There has been an insurgence of allergic respiratory diseases such as asthma and rhinitis in industrialized countries in the last few decades as a result of the interaction between air pollutants and pollen, which has become a global and dramatic health problem. Air pollutants such as nitrogen dioxide, sulfur dioxide, ozone, and carbon dioxide affect the physical, chemical and biological properties of pollen such as the pollen content, production, and allergenicity, exacerbating symptoms in vulnerable subjects. When investigating these interactions and their effects, the environmental impact of climate change, weather variables and urbanization should be taken into account as well as the pollen species, type of pollutant, conditions of exposure, and individual susceptibility. Up to 25% of asthma adult cases are work-related, because several categories of workers in different sectors are exposed to aeroallergens and outdoor air pollutants. Thus, in this study, we evaluated the significant impacts of occupational allergies on worker’s health and quality of life. In summary, to assess the effect of interactions between air pollutants and pollen on public and occupational health, all the factors that play a role in this context will be investigated, including environmental factors, individual susceptibility in relation to pollen species, type of pollutants, and conditions of exposure.

Efficient pollen grain classification using pre-trained Convolutional Neural Networks: a comprehensive study

Pollen identification is necessary for several subfields of geology, ecology, and evolutionary biology. However, the existing methods for pollen identification are laborious, time-consuming, and require highly skilled scientists. Therefore, there is a pressing need for an automated and accurate system for pollen identification, which can be beneficial for both basic research and applied issues such as identifying airborne allergens. In this study, we propose a deep learning (DL) approach to classify pollen grains in the Great Basin Desert, Nevada, USA. Our dataset consisted of 10,000 images of 40 pollen species. To mitigate the limitations imposed by the small volume of our training dataset, we conducted an in-depth comparative analysis of numerous pre-trained Convolutional Neural Network (CNN) architectures utilizing transfer learning methodologies. Simultaneously, we developed and incorporated an innovative CNN model, serving to augment our exploration and optimization of data modeling strategies. We applied different architectures of well-known pre-trained deep CNN models, including AlexNet, VGG-16, MobileNet-V2, ResNet (18, 34, and 50, 101), ResNeSt (50, 101), SE-ResNeXt, and Vision Transformer (ViT), to uncover the most promising modeling approach for the classification of pollen grains in the Great Basin. To evaluate the performance of the pre-trained deep CNN models, we measured accuracy, precision, F1-Score, and recall. Our results showed that the ResNeSt-110 model achieved the best performance, with an accuracy of 97.24%, precision of 97.89%, F1-Score of 96.86%, and recall of 97.13%. Our results also revealed that transfer learning models can deliver better and faster image classification results compared to traditional CNN models built from scratch. The proposed method can potentially benefit various fields that rely on efficient pollen identification. This study demonstrates that DL approaches can improve the accuracy and efficiency of pollen identification, and it provides a foundation for further research in the field.

Regional Pollination Activity by Moth Migration in Athetis lepigone.

Nocturnal moths (Lepidoptera) are important pollinators of a wide range of plant species. Understanding the foraging preferences of these insects is essential for their scientific management. However, this information is lacking for most moth species. The present study was therefore conducted to delineate the host plant feeding and pollination ranges of an agriculturally important nocturnal moth species Athetis lepigone by identifying the pollen species adhering to their bodies during long-distance migration. Pollen grains were dislodged from 1871 A. lepigone migrants captured on Beihuang Island in the Bohai Strait between 2020 and 2021. This region is a key seasonal migration pathway for A. lepigone in northern China. Almost 20% of all moths sampled harbored pollens, providing direct evidences that this moth species may serve as pollinators. Moreover, at least 39 pollen taxa spanning 21 plant families and 31 genera were identified, with a preference for Asteraceae, Amaranthaceae, and Pinaceae. Additionally, the pollen adherence ratios and taxa varied with moth sex, inter-annual changes, and seasonal fluctuations. Most importantly, the pollen taxa were correlated with insect migration stages and indicated that A. lepigone bidirectionally migrates between central China (Shandong, Hebei, and Henan Provinces) and northeastern China (Liaoning Province). Overall, the findings of the present work provide valuable information on the pollination behavior, geographical origins, and pollination regions of A. lepigone moths and could facilitate the design and optimization of efficacious local and regional management strategies for this important insect.

Research Progress on Traditional Medicine, Chemical Composition and Pharmacological Activity of Pine Pollen

In traditional Chinese medicine, “pine yellow” and “pine flower” are the pollen of Pinaceae, commonly Pinus Massoniana Lamb or Pinus tabulaeformis Carr. The pollen of Pinus Massoniana Lamb or Pinus tabulaeformis Carr is common. Pine flower is a unique species of medicinal and edible pollen in the Chinese pharmacopoeia, and is commonly found in ancient Chinese medical and herbal texts, such as “Derivatives of the Materia Medica”, “Classical Materia Medica”, and “Compendium of the Materia Medica”. In this paper, we review the source, history of traditional medicine, and progress of research on pharmacological activity of Chinese pine pollen in order to provide reference for better research on its value.

Aeroallergen Avoidance: Updated Evidence and How to Advise Patients

Allergic rhinitis (AR) is highly prevalent in Canada, affecting approximately 20–25% of the population. Asthma is estimated to affect approximately three million Canadians, and between 12% and 25% of Canadian children. Approximately two-thirds of individuals with asthma are allergic to aeroallergens, and these allergens act as triggers for asthma exacerbations. Overall, approximately 7.7 million individuals were affected by aeroallergens in Canada in 2016. High concentrations of ambient aeroallergens, including tree pollen and fungal spores have been associated with increased risk of premature birth, myocardial infarction (MI) and asthma-related Emergency Department visits and hospitalizations in cities across Canada. This demonstrates that nation-wide aeroallergen counts are associated with severe signs and symptoms. Children exposed to various indoor allergens are placed at an increased risk of developing asthma in later life, with sensitization in these individuals being a strong predictor of disease morbidity. Common indoor exposures for infants include house dust mite, pet, cockroach, mould, and rodent allergens. Sensitization to at least one indoor allergen has been demonstrated to be present in nine of every ten children hospitalized with asthma. It has been noted that more than 90% of children worldwide breathe polluted air. While the impact of climate change on aeroallergen exposure is not fully understood, there is increasing evidence that it may have an impact on outdoor aeroallergens and, by extension, asthma control in children. Global warming has been projected to influence the duration and intensity of pollen seasons, and may lead to increased pollen production, prolonged pollen seasons, and increased pollen protein allergenicity. The changing weather patterns including rainfall and wind may cause pollen species to reach environments in which they had not previously been present, contributing to a shift in geographic pollen distributions.

Eocene to Miocene palynology of the Amagá Basin (Cauca Valley, Colombia) compared to the Caribbean Region

The Cenozoic sedimentary basins of northwestern Colombia contain clues to understanding the evolution of past ecosystems and their possible relationship to regional events, such as the uplift of the northern Andes and the collision of the Panama-Chocó Block with the South American continent. However, these basins have not been thoroughly investigated. This work aims to fill this knowledge gap by performing a comprehensive palynological analysis of the Amagá Basin (Valle del Cauca). Three outcrops were studied to determine their depositional ages, paleoenvironments, and overall floral composition over time. To contextualize our analyses, a comparison was made with two drill holes (ANH-SSJ-Nueva Esperanza-1X and ANH-San Jacinto-1) in the Sinú-San Jacinto Basin in the Colombian Caribbean. The application of the palynological zonation from the Llanos Basin in eastern Colombia was also used to evaluate its suitability in the Amagá Basin. The age of deposition was determined by using several traditional palynostratigraphic markers, including Perisyncolporites pokornyi, Foveotriporites hammeni, Retibrevitricolporites speciosus, Magnastriatites grandiosus, Concavissimisporites fossulatus, Clavainaperturites microclavatus, and Polypodiaceoisporites pseudopsilatus. This assemblage indicates a Middle to Late Eocene, Oligocene, and Miocene age spanning from ~40 to 18 Ma (~22 Myr). However, there are also some differences with respect to the Llanos zonation, such as the absence of Cicatricosisporites dorogensis. Based on this age model, we question whether it is correct to include all these deposits in a single lithostratigraphic unit under the rank of a formation. In the Caribbean, stratigraphic units of similar age exhibit a greater number of key taxa than in the Llanos zonation. In addition, the presence of calcareous microfossils allows for a more detailed determination of the sedimentation age. Furthermore, the discovery of new pollen and spore species could improve the resolution of the biostratigraphy in western Colombia. In the Amagá Basin, only terrestrial palynomorphs were found, which, together with the sedimentary facies, suggest a humid lowland tropical vegetation in fluvial and lacustrine environments.

Evolution Of Immunotherapy Against Pollen Allergy.

Allergic diseases have increased worldwide during the last century and are a major disease burden globally. Several substances can induce allergic sensitization and elicit allergic symptoms in sensitized individuals. Pollen grains are one of the main causes of allergic rhinitis and asthma, and the prevalence of different pollen species depends on the climate, geographical regions, flora, and season. In addition to avoiding exposure to pollens, anti-allergic drugs are commonly used to mitigate the symptoms of allergies. However, these drugs must be administered repeatedly as long as the symptoms prevail, usually life-long. Allergen immunotherapy (AIT) is currently the only disease-modifying approach that can prevent the natural progression of the disease (also known as an allergic march), provide a long-lasting therapeutic effect, and prevent the worsening of the symptoms and the occurrence of new sensitizations in allergic individuals. Since the pioneering clinical studies conducted more than 100 years ago using subcutaneously administered pollen extract to treat hay fever, significant advances have been made in the field of AIT. Starting from this pioneering approach, in this review, we have discussed the evolution of the products used for AIT with particular emphasis on pollen allergoids, the chemically modified pollen extracts characterized by lower allergenicity and comparable immunogenicity, and the different routes of administration used for AIT.