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Ecological Applications : a Publication... Jul 2023Insects are important pollinators of global food crops and wild plants. The adult and larval diet and habitat needs are well known for many bee taxa, but poorly... (Review)
Review
Insects are important pollinators of global food crops and wild plants. The adult and larval diet and habitat needs are well known for many bee taxa, but poorly understood for other pollinating taxa. Non-bee pollinators often feed on different substrates in their larval and adult life stages, and this diet and habitat diversity has important implications for their conservation and management. We reviewed the global literature on crop pollinating Diptera (the true flies) to identify both larval and adult fly diet and habitat needs. We then assembled the published larval and adult diets and habitat needs of beneficial fly pollinators found globally into a freely accessible database. Of the 405 fly species known to visit global food crops, we found relevant published evidence regarding larval and adult diet and habitat information for 254 species, which inhabited all eight global biogeographic regions. We found the larvae of these species lived in 35 different natural habitats and belong to 10 different feeding guilds. Additionally, differences between adult Diptera sexes also impacted diet needs; females from 14 species across five families fed on protein sources other than pollen to start the reproductive process of oogenesis (egg development) while males of the same species fed exclusively on pollen and nectar. While all adult species fed at least partially on floral nectar and/or pollen, only five species were recorded feeding on pollen and no fly larvae fed on nectar. Of the 242 species of larvae with established diet information, 33% were predators (nā=ā79) and 30% were detritivores (nā=ā73). Detritivores were the most generalist taxa and utilized 17 different habitats and 12 different feeding substrates. Of all fly taxa, only 2% belonged to the same feeding guild in both active life stages. Our results show that many floral management schemes may be insufficient to support pollinating Diptera. Pollinator conservation strategies in agroecosystems should consider other non-floral resources, such as wet organic materials and dung, as habitats for beneficial fly larvae.
Topics: Animals; Bees; Plant Nectar; Larva; Pollination; Ecosystem; Diptera; Crops, Agricultural; Diet; Flowers
PubMed: 37092886
DOI: 10.1002/eap.2859 -
Trends in Plant Science Feb 2016Research on herbivore-induced plant defence and research on pollination ecology have had a long history of separation. Plant reproduction of most angiosperm species is... (Review)
Review
Research on herbivore-induced plant defence and research on pollination ecology have had a long history of separation. Plant reproduction of most angiosperm species is mediated by pollinators, and the effects of herbivore-induced plant defences on pollinator behaviour have been largely neglected. Moreover, there is expected to be a trade-off between plant reproductive strategies and defence mechanisms. To investigate this trade-off, it is essential to study herbivore-induced plant resistance and allocation of resources by plants, within the same system, and to test if indirect plant resistance can conflict with pollinator attraction. Here, I review the key literature highlighting connection between plant defence and reproduction, and propose to exploit natural variation among plant species to assess the ecological costs of plant responses to herbivores and pollinators.
Topics: Animals; Flowers; Herbivory; Host-Parasite Interactions; Plants; Pollination; Reproduction; Volatile Organic Compounds
PubMed: 26598297
DOI: 10.1016/j.tplants.2015.10.013 -
Proceedings. Biological Sciences Apr 2017The effects of specific functional groups of pollinators in the diversification of angiosperms are still to be elucidated. We investigated whether the pollination shifts...
The effects of specific functional groups of pollinators in the diversification of angiosperms are still to be elucidated. We investigated whether the pollination shifts or the specific association with hummingbirds affected the diversification of a highly diverse angiosperm lineage in the Neotropics. We reconstructed a phylogeny of 583 species from the Gesneriaceae family and detected diversification shifts through time, inferred the timing and amount of transitions among pollinator functional groups, and tested the association between hummingbird pollination and speciation and extinction rates. We identified a high frequency of pollinator transitions, including reversals to insect pollination. Diversification rates of the group increased through time since 25 Ma, coinciding with the evolution of hummingbird-adapted flowers and the arrival of hummingbirds in South America. We showed that plants pollinated by hummingbirds have a twofold higher speciation rate compared with plants pollinated by insects, and that transitions among functional groups of pollinators had little impact on the diversification process. We demonstrated that floral specialization on hummingbirds for pollination has triggered rapid diversification in the Gesneriaceae family since the Early Miocene, and that it represents one of the oldest identified plant-hummingbird associations. Biotic drivers of plant diversification in the Neotropics could be more related to this specific type of pollinator (hummingbirds) than to shifts among different functional groups of pollinators.
Topics: Animals; Birds; Flowers; Genetic Speciation; Magnoliopsida; Phylogeny; Pollination; South America
PubMed: 28381621
DOI: 10.1098/rspb.2016.2816 -
Current Opinion in Insect Science Jun 2016Floral scents act as long-distance signals to attract pollinators, but volatiles emitted from the vegetation and neighboring plant community may modify this mutualistic... (Review)
Review
Floral scents act as long-distance signals to attract pollinators, but volatiles emitted from the vegetation and neighboring plant community may modify this mutualistic communication system. What impact does the olfactory background have on pollination systems and their evolution? We consider recent behavioral studies that address the context of when and where volatile backgrounds influence a pollinator's perception of floral blends. In parallel, we review neurophysiological studies that show the importance of blend composition and background in modifying the representation of floral blends in the pollinator brain, as well as experience-dependent plasticity in increasing the representation of a rewarding odor. Here, we suggest that the efficacy of the floral blend in different environments may be an important selective force shaping differences in pollinator olfactory receptor expression and underlying neural mechanisms that mediate flower visitation and plant reproductive isolation.
Topics: Animals; Flowers; Insecta; Plants; Pollination; Receptors, Odorant; Reproductive Isolation; Smell
PubMed: 27436732
DOI: 10.1016/j.cois.2016.03.007 -
Current Biology : CB Dec 2022A single CRISPR-generated mutation in a MYB transcription factor in Petunia leads to a dual phenotype. This in turn has a dual effect on potential pollinating insects,...
A single CRISPR-generated mutation in a MYB transcription factor in Petunia leads to a dual phenotype. This in turn has a dual effect on potential pollinating insects, deterring the original pollinator while increasing the visitation of a possible replacement.
Topics: Animals; Pollination; Clustered Regularly Interspaced Short Palindromic Repeats; Ecology; Insecta; Transcription Factors; Flowers
PubMed: 36538885
DOI: 10.1016/j.cub.2022.11.023 -
Annals of Botany Oct 2023Dipteran insects are known pollinators of many angiosperms, but knowledge on how flies affect floral evolution is relatively scarce. Some plants pollinated by fungus...
BACKGROUND AND AIMS
Dipteran insects are known pollinators of many angiosperms, but knowledge on how flies affect floral evolution is relatively scarce. Some plants pollinated by fungus gnats share a unique set of floral characters (dark red display, flat shape and short stamens), which differs from any known pollination syndromes. We tested whether this set of floral characters is a pollination syndrome associated with pollination by fungus gnats, using the genus Euonymus as a model.
METHODS
The pollinator and floral colour, morphology and scent profile were investigated for ten Euonymus species and Tripterygium regelii as an outgroup. The flower colour was evaluated using bee and fly colour vision models. The evolutionary association between fungus gnat pollination and each plant character was tested using a phylogenetically independent contrast. The ancestral state reconstruction was performed on flower colour, which is associated with fungus gnat pollination, to infer the evolution of pollination in the genus Euonymus.
KEY RESULTS
The red-flowered Euonymus species were pollinated predominantly by fungus gnats, whereas the white-flowered species were pollinated by bees, beetles and brachyceran flies. The colour vision analysis suggested that red and white flowers are perceived as different colours by both bees and flies. The floral scents of the fungus gnat-pollinated species were characterized by acetoin, which made up >90 % of the total scent in three species. Phylogenetically independent contrast showed that the evolution of fungus gnat pollination is associated with acquisition of red flowers, short stamens and acetoin emission.
CONCLUSIONS
Our results suggest that the observed combination of floral characters is a pollination syndrome associated with the parallel evolution of pollination by fungus gnats. Although the role of the red floral display and acetoin in pollinator attraction remains to be elucidated, our finding underscores the importance of fungus gnats as potential contributors to floral diversification.
Topics: Bees; Animals; Pollination; Euonymus; Acetoin; Diptera; Fungi; Flowers
PubMed: 37610846
DOI: 10.1093/aob/mcad081 -
Philosophical Transactions of the Royal... Aug 2014Within-individual variation in virtually every conceivable morphological and functional feature of reiterated structures is a pervasive feature of plant phenotypes. In... (Review)
Review
Within-individual variation in virtually every conceivable morphological and functional feature of reiterated structures is a pervasive feature of plant phenotypes. In particular, architectural effects, regular, repeatable patterns of intra-individual variation in form and function that are associated with position are nearly ubiquitous. Yet, flowers also are predicted to be highly integrated. For animal-pollinated plants, the coordination of multiple organs within each flower is required to achieve the complex functions of pollinator attraction and orientation, pollen donation and pollen receipt. To the extent that pollinators may select for multiple independent functions, phenotypic integration within flowers may also be modular. That is, subsets of floral structures may be integrated but vary independently of other subsets of structures that are themselves integrated. How can phenotypic integration and modularity be understood within the context of architectural effects? This essay reviews recent research on patterns of floral integration and modularity and explores the potential for spatial and temporal changes in the selective environment of individual flowers to result in positional variation in patterns of morphological integration.
Topics: Biological Evolution; Flowers; Models, Biological; Phenotype; Plants; Pollination; Systems Biology
PubMed: 25002698
DOI: 10.1098/rstb.2013.0253 -
The American Naturalist Apr 2024AbstractEcologists increasingly recognize that interactions between two species can be affected by the density of a third species. How these higher-order interactions...
AbstractEcologists increasingly recognize that interactions between two species can be affected by the density of a third species. How these higher-order interactions (HOIs) affect species persistence remains poorly understood. To explore the effect of HOIs stemming from multiple trophic layers on a plant community composition, we experimentally built a mesocosm with three plants and three pollinator species arranged in a fully nested and modified network structure. We estimated pairwise interactions among plants and between plants and pollinators, as well as HOIs initiated by a plant or a pollinator affecting plant species pairs. Using a structuralist approach, we evaluated the consequences of the statistically supported HOIs on the persistence probability of each of the three competing plant species and their combinations. HOIs substantially redistribute the strength and sign of pairwise interactions between plant species, promoting the opportunities for multispecies communities to persist compared with a non-HOI scenario. However, the physical elimination of a plant-pollinator link in the modified network structure promotes changes in per capita pairwise interactions and HOIs, resulting in a single-species community. Our study provides empirical evidence of the joint importance of HOIs and network structure in determining species persistence within diverse communities.
Topics: Pollination; Plants
PubMed: 38489780
DOI: 10.1086/729222 -
American Journal of Botany Dec 2022Evidence suggests that bees may benefit from moderate levels of human development. However, the effects of human development on pollination and reproduction of...
PREMISE
Evidence suggests that bees may benefit from moderate levels of human development. However, the effects of human development on pollination and reproduction of bee-pollinated plants are less-well understood. Studies have measured natural variation in pollination and plant reproduction as a function of urbanization, but few have experimentally measured the magnitude of pollen limitation in urban vs. non-urban sites. Doing so is important to unambiguously link changes in pollination to plant reproduction. Previous work in the Southeastern United States found that urban sites supported twice the abundance of bees compared to non-urban sites. We tested the hypothesis that greater bee abundance in some of the same urban sites translates into reduced pollen limitation compared to non-urban sites.
METHODS
We manipulated pollination to three native, wild-growing, bee-pollinated plants: Gelsemium sempervirens, Oenothera fruticosa, and Campsis radicans. Using supplemental pollinations, we tested for pollen limitation of three components of female reproduction in paired urban and non-urban sites. We also measured pollen receipt as a proxy for pollinator visitation.
RESULTS
We found that all three plant species were pollen-limited for some measures of female reproduction. However, opposite to our original hypothesis, two of the three species were more pollen-limited in urban relative to non-urban sites. We found that open-pollinated flowers in urban sites received less conspecific and more heterospecific pollen on average than those in non-urban sites.
CONCLUSIONS
These results suggest that even when urban sites have more abundant pollinators, this may not alleviate pollen limitation of native plant reproduction in urban landscapes.
Topics: Animals; Humans; Bees; Gelsemium; Pollen; Pollination; Reproduction; Plant Physiological Phenomena
PubMed: 36200335
DOI: 10.1002/ajb2.16080 -
Nature Ecology & Evolution Jan 2023Animal-mediated pollination is a vital ecosystem service to crops and wild plants, and long-term stability of plant-pollinator interactions is therefore crucial for...
Animal-mediated pollination is a vital ecosystem service to crops and wild plants, and long-term stability of plant-pollinator interactions is therefore crucial for maintaining plant biodiversity and food security. However, it is unknown how the composition of pollinators and the structure of pollinator interactions have changed across longer time spans relevant to examining responses to human activities such as climate change. We resampled an historical dataset of plant-pollinator interactions across several orders of pollinating insects in a subarctic location in Finland that has already experienced substantial climate warming but little land use change. Our results reveal a dramatic turnover in pollinator species and rewiring of plant-pollinator interactions, with only 7% of the interactions shared across time points. The relative abundance of moth and hoverfly pollinators declined between time points, whereas muscoid flies, a group for which little is known regarding conservation status and responses to climate, became more common. Specialist pollinators disproportionately declined, leading to a decrease in network-level specialization, which could have harmful consequences for pollination services. Our results exemplify the changes in plant-pollinator networks that might be expected in other regions as climate change progresses.
Topics: Animals; Humans; Ecosystem; Insecta; Pollination; Biodiversity; Crops, Agricultural
PubMed: 36593294
DOI: 10.1038/s41559-022-01928-3