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The New Phytologist Oct 2023Most contemporary angiosperms (flowering plants) are insect pollinated, but pollination by wind, water or vertebrates occurs in many lineages. Though evidence suggests...
Most contemporary angiosperms (flowering plants) are insect pollinated, but pollination by wind, water or vertebrates occurs in many lineages. Though evidence suggests insect pollination may be ancestral in angiosperms, this is yet to be assessed across the full phylogeny. Here, we reconstruct the ancestral pollination mode of angiosperms and quantify the timing and environmental associations of pollination shifts. We use a robust, dated phylogeny and species-level sampling across all angiosperm families to model the evolution of pollination modes. Data on the pollination system or syndrome of 1160 species were collated from the primary literature. Angiosperms were ancestrally insect pollinated, and insects have pollinated angiosperms for c. 86% of angiosperm evolutionary history. Wind pollination evolved at least 42 times, with few reversals to animal pollination. Transitions between insect and vertebrate pollination were more frequent: vertebrate pollination evolved at least 39 times from an insect-pollinated ancestor with at least 26 reversals. The probability of wind pollination increases with habitat openness (measured by Leaf Area Index) and distance from the equator. Our reconstruction gives a clear overview of pollination macroevolution across angiosperms, highlighting the long history of interactions between insect pollinators and angiosperms still vital to biodiversity today.
Topics: Humans; Animals; Pollination; Magnoliopsida; Insecta; Phylogeny; Wind; Flowers
PubMed: 37276503
DOI: 10.1111/nph.18993 -
Trends in Ecology & Evolution May 2024Plant-pollinator interactions are ecologically and economically important, and, as a result, their prediction is a crucial theoretical and applied goal for ecologists.... (Review)
Review
Plant-pollinator interactions are ecologically and economically important, and, as a result, their prediction is a crucial theoretical and applied goal for ecologists. Although various analytical methods are available, we still have a limited ability to predict plant-pollinator interactions. The predictive ability of different plant-pollinator interaction models depends on the specific definitions used to conceptualize and quantify species attributes (e.g., morphological traits), sampling effects (e.g., detection probabilities), and data resolution and availability. Progress in the study of plant-pollinator interactions requires conceptual and methodological advances concerning the mechanisms and species attributes governing interactions as well as improved modeling approaches to predict interactions. Current methods to predict plant-pollinator interactions present ample opportunities for improvement and spark new horizons for basic and applied research.
Topics: Animals; Pollination; Models, Biological; Insecta; Plants
PubMed: 38262775
DOI: 10.1016/j.tree.2023.12.005 -
Integrative Zoology May 2024Honeybees are the most critical pollinators providing key ecosystem services that underpin crop production and sustainable agriculture. Amidst a backdrop of rapid global... (Review)
Review
Honeybees are the most critical pollinators providing key ecosystem services that underpin crop production and sustainable agriculture. Amidst a backdrop of rapid global change, this eusocial insect encounters a succession of stressors during nesting, foraging, and pollination. Ectoparasitic mites, together with vectored viruses, have been recognized as central biotic threats to honeybee health, while the spread of invasive giant hornets and small hive beetles also increasingly threatens colonies worldwide. Cocktails of agrochemicals, including acaricides used for mite treatment, and other pollutants of the environment have been widely documented to affect bee health in various ways. Additionally, expanding urbanization, climate change, and agricultural intensification often result in the destruction or fragmentation of flower-rich bee habitats. The anthropogenic pressures exerted by beekeeping management practices affect the natural selection and evolution of honeybees, and colony translocations facilitate alien species invasion and disease transmission. In this review, the multiple biotic and abiotic threats and their interactions that potentially undermine bee colony health are discussed, while taking into consideration the sensitivity, large foraging area, dense network among related nestmates, and social behaviors of honeybees.
Topics: Bees; Animals; Stress, Physiological; Mites; Introduced Species; Climate Change; Pollination
PubMed: 37427560
DOI: 10.1111/1749-4877.12752 -
Plant Biology (Stuttgart, Germany) Apr 2024Floral colours represent a highly diverse communication signal mainly involved in flower visitors' attraction and guidance, but also flower discrimination, filtering... (Review)
Review
Floral colours represent a highly diverse communication signal mainly involved in flower visitors' attraction and guidance, but also flower discrimination, filtering non-pollinators and discouraging floral antagonists. The divergent visual systems and colour preferences of flower visitors, as well as the necessity of cues for flower detection and discrimination, foster the diversity of floral colours and colour patterns. Despite the bewildering diversity of floral colour patterns, a recurrent component is a yellow UV-absorbing floral centre, and it is still not clear why this pattern is so frequent in angiosperms. The pollen, anther, stamen, and androecium mimicry (PASAM) hypothesis suggests that the system composed of the flowers possessing such yellow UV-absorbing floral reproductive structures, the flowers displaying central yellow UV-absorbing structures as floral guides, and the pollen-collecting, as well as pollen-eating, flower visitors responding to such signals constitute the world's most speciose mimicry system. In this review, we call the attention of researchers to some hypothetical PASAM systems around the globe, presenting some fascinating examples that illustrate their huge diversity. We will also present new and published data on pollen-eating and pollen-collecting pollinators' responses to PASAM structures supporting the PASAM hypothesis and will discuss how widespread these systems are around the globe. Ultimately, our goal is to promote the idea that PASAM is a plausible first approach to understanding floral colour patterns in angiosperms.
Topics: Pollination; Reproduction; Flowers; Pollen; Magnoliopsida
PubMed: 38407440
DOI: 10.1111/plb.13628 -
Biologia Futura Dec 2023The importance of pollination and pollinators is easy to underestimate and impossible to overstate, since its importance goes far beyond the crop production and even the... (Review)
Review
The importance of pollination and pollinators is easy to underestimate and impossible to overstate, since its importance goes far beyond the crop production and even the maintenance of plant populations. Most terrestrial ecosystems ultimately depend on the plant-pollinator interactions formed by million years coevolution. This is essential for both the daily functioning of the ecosystems and the long-term development of biodiversity. At the same time, the loss of biodiversity caused by climate change and human activities will soon lead to an ecological crisis, a catastrophe, which could endanger our life: For example, through the decline and loss of various ecosystem services. Such may be the pollination crisis, resulted from a significant loss of pollinating insects' diversity and abundance. The discovery of a pollinator Orthoptera species has encouraged researchers in the densely populated region of Indo-Malaysia to explore the potential role of orthopterans as pollinators. Although the flower visitation of some species has been already known, the role of orthopterans in pollination is scarcely revealed. Here, we collected and reviewed the available data in order to point out some factors of their importance and set priorities that may serve as a basis for further investigations regarding ecological, evolutionary and practical points of view.
Topics: Animals; Humans; Ecosystem; Pollination; Insecta; Orthoptera; Flowers
PubMed: 38349457
DOI: 10.1007/s42977-024-00203-9 -
AoB PLANTS Oct 2023Orchidaceae, one of the most numerous families in the world's flora, have evolved various pollination strategies to favour cross-pollination, such as deceptive...
Orchidaceae, one of the most numerous families in the world's flora, have evolved various pollination strategies to favour cross-pollination, such as deceptive pollination and pollinarium reconfiguration. Among the terrestrial orchids of the Mediterranean, only species belonging to the genus show a strategy defined as shelter imitation. The floral elements form a tubular structure that insects use during their resting phases. The purpose of this article was to clarify the mechanisms that guarantee pollination with particular attention to the morphological interactions between orchids and pollinators and whether pollinaria reconfiguration is necessary in the promotion of cross-pollination in . Breeding system experiments and hand-pollination treatments indicated that was highly self-compatible, shows low value of natural fruit set and is pollinator limited. Time-lapse photos showed that the pollinarium had no refolding of the stipe or caudicle after its removal from the flower. The morphology of the flower determined the attack of the pollinarium on the occiput/vertex of insect. When the insect left the flower, the pollinarium was unable to encounter the stigma. When the insect made a second visit to another flower, the pollen masses of the first pollinarium ended up on the stigma and at the same time, the insect picked up a second pollinarium. Our observations and analyses suggested that morphological interactions between flower and pollinator are crucial to the success of pollination and to prevent self-pollination and thus that pollinarium reconfiguration is unnecessary in shelter deceptive orchids, such as species, for the promotion of cross-pollination. represent a case of interactions between plant and pollinator; the formation of the tubular shape of the flower is an essential preadaptation for the development of resting site mimicry originating exclusively in among Mediterranean orchids.
PubMed: 37899971
DOI: 10.1093/aobpla/plad054 -
Frontiers in Plant Science 2023shows a set of floral traits that suggest elaborate mechanisms of animal-mediated pollen transfer. These include flower coloration, septal nectaries and a long and...
shows a set of floral traits that suggest elaborate mechanisms of animal-mediated pollen transfer. These include flower coloration, septal nectaries and a long and narrow floral chamber. The stamens are synorganized with the common style restricting the entrance to the floral chamber, sometimes forming a gynostegium. Contrary to this apparent zoophilous floral syndrome, several species of were reported to perform self-pollination via cleistogamy. Understanding of reproductive systems in is complicated by scarcity of available results of direct observations on pollination process. Here we present data on pollination biology of obtained during field investigations in Vietnam followed by laboratory analyses of ecologically important floral traits and the captured flower visitors. We found that the anthetic perianth is open, i.e. the flower is chasmogamous. The flowers are visited by various Diptera, Hymenoptera, Lepidoptera and Orthoptera. Of them, the bumblebees (), a bee ( sp.) and some lepidopterans were revealed to carry pollen of . Based on the amount of carried pollen, insect behavior during the visits and general knowledge on biology of these insect taxa, we concluded that the bumblebees act as the principal pollinators of , whereas the lepidopterans are considered as its possible pollinators. We compared the lengths of proboscises of the captured insects to the depth of the floral chamber, and found that only the bumblebees and lepidopterans should be able to reach the nectar. Finally, we estimated the pollen-ovule ratio of as 6.84, which is comparable to the ratio known in autogamous angiosperms. Based on its flower organization and pollination mechanism, we consider an entomophilous and predominantly xenogamous species. Its gynostegium is likely an adaptation for pollen transfer by insects with long proboscises. At the same time, earlier investigations together with pollen-ovule ratio indicate that possesses a labile pollination strategy, and autogamy sometimes occurs. Since is one of the few angiosperm genera that comprise both mycoheterotrophic (achlorophyllous) and autotrophic (green) species, our study provides important evidence for reconstructions of ecological and morphological evolutionary pathways in relation to the mode of organic nutrition.
PubMed: 37680363
DOI: 10.3389/fpls.2023.1237665 -
The Science of the Total Environment Oct 2023Solitary bees are important pollinators of crops and wild plants, and their decline poses a risk to the sustained provision of the services they provide. Although...
Solitary bees are important pollinators of crops and wild plants, and their decline poses a risk to the sustained provision of the services they provide. Although evidence suggests that exposure to insecticides can affect bees, most pesticide research and risk assessment has focussed on social bees and mortality while solitary species are understudied. The ability to forage is critical for solitary bee reproduction, also in how they deliver pollination services, and we know little about how insecticides can impact these behaviours. We exposed solitary red mason bees (Osmia bicornis) to field realistic levels of two widely used insecticides with differing modes of action (lambda-cyhalothrin (pyrethroid) and acetamiprid (neonicotinoid)), in a semi-field setting over multiple rounds of exposure. We then tested impacts on bee behaviour and pollination in apples, an important global insect-pollinated crop. Pollination by insecticide-treated bees reduced apple production by up to 86 % depending on the compound and the number of exposures, but the underlying mechanism behind this remains unclear and should be investigated further. Other measurements of pollination services including number of seeds per apple and stigma pollen deposition showed no relationship with pesticide treatment. Bee foraging behaviour was also affected by treatment where both insecticides appear to induce an excitatory effect which was constant for acetamiprid and eventually ceased for lambda-cyhalothrin after multiple exposures. This suggests that both neonicotinoid and non‑neonicotinoid insecticides can potentially affect behaviour and pollination services of solitary bees depending on how often they are exposed, which is particularly important given the changing usage patterns of these compound classes based on regulations around their use. This highlights the importance of moving insecticide risk assessment towards more field realistic scenarios and including sublethal effects on solitary and social bees, in addition to considering repeated exposures of bees to pesticides as is realistic in the field.
Topics: Bees; Animals; Insecticides; Pollination; Pyrethrins; Neonicotinoids; Pesticides
PubMed: 37245806
DOI: 10.1016/j.scitotenv.2023.164399 -
Insects Nov 2023Pollination services provided by a diversity of pollinators are critical in agriculture because they enhance the yield of many crops. However, few studies have assessed...
Pollination services provided by a diversity of pollinators are critical in agriculture because they enhance the yield of many crops. However, few studies have assessed pollination services in urban agricultural systems. We performed flower-visitor observations and pollination experiments on strawberries () in an urban area near Paris, France, in order to assess the effects of (i) insect-mediated pollination service and (ii) potential pollination deficit on fruit set, seed set, and fruit quality (size, weight, and malformation). Flower-visitor observations revealed that the pollinator community solely comprised unmanaged pollinators, despite the presence of beehives in the surrounding landscape. Based on the pollination experiments, we found that the pollination service mediated by wild insects improved the fruit size as a qualitative value of production, but not the fruit set. We also found no evidence of pollination deficit in our urban environment. These results suggest that the local community of wild urban pollinators is able to support strawberry crop production and thus plays an important role in providing high-quality, local, and sustainable crops in urban areas.
PubMed: 37999076
DOI: 10.3390/insects14110877 -
Biological Reviews of the Cambridge... Dec 2023Sexual selection is considered one of the key processes that contribute to the emergence of new species. While the connection between sexual selection and speciation has... (Review)
Review
Sexual selection is considered one of the key processes that contribute to the emergence of new species. While the connection between sexual selection and speciation has been supported by comparative studies, the mechanisms that mediate this connection remain unresolved, especially in plants. Similarly, it is not clear how speciation processes within plant populations translate into large-scale speciation dynamics. Here, we review the mechanisms through which sexual selection, pollination, and mate choice unfold and interact, and how they may ultimately produce reproductive isolation in plants. We also overview reproductive strategies that might influence sexual selection in plants and illustrate how functional traits might connect speciation at the population level (population differentiation, evolution of reproductive barriers; i.e. microevolution) with evolution above the species level (macroevolution). We also identify outstanding questions in the field, and suitable data and tools for their resolution. Altogether, this effort motivates further research focused on plants, which might potentially broaden our general understanding of speciation by sexual selection, a major concept in evolutionary biology.
Topics: Genetic Speciation; Sexual Selection; Reproduction; Pollination; Plants; Selection, Genetic
PubMed: 37337476
DOI: 10.1111/brv.12991