Visual and olfactory floral cues related to ambophilous pollination systems in Poaceae

Author(s):  
Isadora Schulze-Albuquerque ◽  
Ana Carolina Galindo Da Costa ◽  
Paulo Milet-Pinheiro ◽  
Daniela Maria Do Amaral Ferraz Navarro ◽  
William Wayt Thomas ◽  
...  

Abstract Usually considered anemophilous, grasses (Poaceae) have been the subject of few studies that recorded insects visiting their flowers. Such visitors, with wind, could act as pollen vectors in a possible ambophilous system. Since colour and scent are floral cues attracting pollinating insects, we aimed to provide the first insights into how these cues could be involved in the attraction of pollinators by grasses. Chloris barbata, Paspalum maritimum (with two morphotypes), P. millegrana and Urochloa plantaginea were studied. We determined the role of each pollen vector (wind and insect) and we registered the frequency of floral visitors. Also, we characterized the colour reflectance of glumes, anthers and stigmas and we determined the colour space in the bee colour hexagon and the chemical composition of floral scents. The floral structures of each species reflect colour differently and are perceived differently by pollinators. Furthermore, the volatile organic compounds detected are similar to those found in entomophilous species. In two of the grass species, we registered eight species of visitors, including bees, wasps and flies. Overall, wind was the most important vector for reproductive success. Insects, however, may induce wind pollination by creating pollen clouds when they visit inflorescences.

Sociobiology ◽  
2020 ◽  
Vol 67 (2) ◽  
pp. 173
Author(s):  
Bruno De Sousa-Lopes ◽  
Eduardo Soares Calixto ◽  
Eduardo Soares Calixto ◽  
Helena Maura Torezan-Silingardi ◽  
Helena Maura Torezan-Silingardi ◽  
...  

Besides the eff ectiveness of floral visitors, to better understand pollination systems is necessary to consider the role of predators. Ants are ubiquitous on the vegetation, especially on plants bearing extrafloral (EFNs) and pericarpial nectaries (PNs). Both EFNs and PNs reward ants which in turn provide to plants effective protection against herbivores. However, ants can also repel pollinators and cause an indirect cost for the plant partner, although the role of ants on pollinators’ performance has rarely been assessed in Neotropics, mainly on PN-bearing plants. Here, our main aim was, through an experimental field study in terms of ant’s presence versus absence, to test the hypothesis that ants dissuade floral visitors by decreasing the time spent during visits on the PN-bearing Declieuxia fruticosa. Additionally, we recorded floral phenology, and quantified and qualified floral visits. We showed that bees were the most frequent pollinators and the presence of ants dissuades them. In ant presence, pollinators were on average 30% faster than without ants. Since D. fruticosa produces fruits mainly after cross-pollination, the role of ants may be profi table to plants as they induce pollinators to do shorter visits and search for other fl owers in conspecifi c plants. Therefore, pollinators avoid stay at longer on plants with ants in order to avoid attacks, which may contribute to plant outcrossing. However, whether positive or negative the effects of ants on D. fruticosa reproduction are, they remain to be studied.


2021 ◽  
Vol 106 ◽  
pp. 372-391
Author(s):  
Ana Carolina Galindo da Costa ◽  
William Wayt Thomas ◽  
Artur Campos D. Maia ◽  
Daniela Maria do Amaral Ferraz Navarro ◽  
Paulo Milet-Pinheiro ◽  
...  

Floral colors and odors are evolutionary strategies used by plants to attract pollinating animals and may be absent in mostly anemophilous groups, such as Cyperaceae. However, considering that insects are floral visitors of some Rhynchospora Vahl species, the objective of this study was to characterize the floral traits and pollination systems within this genus. We analyzed 16 Rhynchospora species with regard to flower morphology, colors of floral structures, floral scents, pollen vectors, and pollination systems. We verified factors that can favor abiotic or biotic pollination in a continuum of floral traits in Rhynchospora. The flower morphology of R. dissitispicula T. Koyama, with inconspicuous brown spikelets in open panicles, is interpreted as a complete adaptation to anemophily. Conspicuous floral traits in Rhynchospora were distinguished from the background by bees. Some species also emit floral volatiles, and we made the first record of floral scent chemistry within the genus. Most of the compounds emitted by these species are known as attractants to many floral-visiting insects. Bees, beetles, and flies visited species with conspicuous floral traits and contributed to fruit set. The investigated floral traits form a continuum across the different pollination systems in Rhynchospora, from anemophilous to ambophilous and then to entomophilous representatives.


Diversity ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 148
Author(s):  
Mani Shrestha ◽  
Jair E. Garcia ◽  
Freya Thomas ◽  
Scarlett R. Howard ◽  
Justin H. J. Chua ◽  
...  

There is increasing interest in developing urban design principles that incorporate good ecological management. Research on understanding the distribution and role of beneficial pollinating insects, in particular, is changing our view of the ecological value of cities. With the rapid expansion of the built environment comes a need to understand how insects may be affected in extensive urban areas. We therefore investigated insect pollinator capture rates in a rapidly growing and densely urbanized city (Melbourne, Australia). We identified a remnant native habitat contained within the expansive urban boundary, and established study sites at two nearby populated urban areas. We employed standard pan trap sampling techniques to passively sample insect orders in the different environments. Our results show that, even though the types of taxonomic groups of insects captured are comparable between locations, important pollinators like bees and hoverflies were more frequently captured in the remnant native habitat. By contrast, beetles (Coleoptera) and butterflies/moths (Lepidoptera) were more frequently observed in the urban residential regions. Our results suggest that the maintenance of native habitat zones within cities is likely to be valuable for the conservation of bees and the ecosystem services they provide.


2021 ◽  
Vol 135 (2) ◽  
pp. 186-191
Author(s):  
Paul M. Catling ◽  
Brenda Kostiuk ◽  
Jeffrey H. Skevington

Alaska Wild Rhubarb (Koenigia alaskana var. glabrescens; Polygonaceae) is a native Arctic, subarctic, and alpine plant of northwestern North America. Although the plant has some economic and ecological importance, its biology is poorly known. At 11 sites in the northeast corner of its range in Northwest Territories, we found that 87% of its floral visitors were flies, mostly Syrphidae, a diverse family known to be important pollinators. Insects visiting consecutive flowers on different plants and, thus, likely effecting pollination were also flies (78.6%) and also mostly Syrphidae (72.7%) followed by Hymenoptera (20%). Although syrphids were the dominant potential pollinators at most sites, there was some variation among sites. Our results provide quantitative support for pollinator diversity and the major role of Syrphidae in pollination of Alaska Wild Rhubarb. We suggest that pollination is not a limiting factor in this plant’s spread, nor its rare and local occurrence and restricted distribution, because the majority of its pollinators are widespread.


2021 ◽  
Vol 901 (1) ◽  
pp. 012007
Author(s):  
V M Kosolapov ◽  
V I Cherniavskih ◽  
E V Dumacheva ◽  
M N Marinich ◽  
L D Sajfutdinova ◽  
...  

Abstract We evaluated the stability of perennial legume and cereal grass species in artificial plant communities on permanent anti-erosion watercourses in the agroecosystems of the Belgorod region with active development of linear soil erosion. In the conditions of steppe and forest-steppe zones of the Belgorod region on permanently grassed watercourses in 2017-2019. varieties of perennial leguminous and cereal grasses: ‘Krasnoyaruzhskaya 1’ and ‘Krasnoyaruzhskaya 2’ (Medicago varia), ‘Kazatsky’ (Trifolium pratense), ‘Olshanka’ and ‘Ivica’ (Festuca arundinacea), ‘Streletsky’ and ‘Stepnyak’ (Lolium perenne)) obtained using local genetic material were studied. All varieties showed their resistance in agro-ecosystems with active development of linear erosion in the forest-steppe and steppe zones. Projective cover on watercourses in the steppe zone in all variants of experience was on average 83,4 %, in the forest-steppe zone - 86,3 %. In the third year of the tests on permanently irrigated watercourses in the steppe zone, the share of cereal and legume grass species was quite high and varied from 88 % in the variant M. varia + Onobrychis arenaria to 92 % in the variants M. varia + Bromopsis inermis and O. arenaria. In the forest-steppe zone, the share of cereal and legume grass species varied from 86 % in the variant L. perenne to 94 % in the variant L. perenne + B. inermis.


2019 ◽  
Vol 192 (4) ◽  
pp. 840-854
Author(s):  
Aline C Gomes ◽  
Bruno H S Ferreira ◽  
Camila S Souza ◽  
Luan M M Arakaki ◽  
Camila Aoki ◽  
...  

Abstract Some epiphytes are adapted to extreme environments with the ability to survive drought as a result of their morphological (xeromorphism), anatomical (foliar trichomes or scales) and physiological features. In contrast to vegetative features, they may have diverse sexual reproductive strategies. Here we compared the flowering morphology, floral biology, breeding system and pollinators of Tillandsia duratii, T. loliacea and T. recurvifolia (Bromeliaceae) adapted to an extreme environment, the Brazilian Chaco. Tillandsia duratii and T. recurvifolia flower for 5–6 months, whereas T. loliaceae flowers for 11 months, mainly in the dry season, with low to high flowering overlap between them. Although these species generally show similar flowering morphology, they differ in size, colour, odour and/or floral functionality, suggesting non-sharing of pollinators among them. Bimodal pollination occurs in T. duratii (bees, moths other than hawkmoths) and T. recurvifolia (butterflies, hummingbirds); in T. loliacea, we recorded no floral visitors. Tillandsia recurvifolia is self-incompatible, has flowers which approach herkogamy and protandry, and depends on pollen vectors for fruit set. The other two species show reverse herkogamy, autonomous self-pollination and self-compatibility (mixed breeding system); therefore, pollinators are not required. The disparity in reproductive strategies among the three species suggests the possibility of selection for diverse modes of reproduction.


2019 ◽  
Vol 67 (7) ◽  
pp. 490 ◽  
Author(s):  
Noushka Reiter ◽  
Björn Bohman ◽  
Marc Freestone ◽  
Graham R. Brown ◽  
Ryan D. Phillips

Prior to undertaking conservation translocations of plants with specialised pollination systems, it is important to ensure the presence of pollinators at recipient sites. Here, for two threatened species, Caladenia concolor Fitzg. and Caladenia arenaria Fitzg. (Orchidaceae), we determine (i) the pollination strategy used, (ii) which floral visitors are involved in pollination, and (iii) whether the pollinator species are present at potential translocation sites. For both orchid species, pollination was primarily achieved by nectar-foraging thynnine wasps, with a single species responsible for pollination in C. concolor, whereas C. arenaria utilised at least two species to achieve pollination. Both orchid species secreted meagre quantities of sucrose on the upper surface of the labellum. Visits to C. concolor occurred primarily in the late afternoon, with some wasps perching on the flowers overnight. Surveys revealed that pollinators were present at all extant populations and most potential translocation sites for both orchids. The specialisation on one pollinator species in C. concolor means that the distribution of the pollinator needs to be considered for conservation translocations. With C. arenaria, the risk of hybridisation with other Caladenia that are known to share one of its pollinator species needs to be taken into account when selecting translocation sites.


Author(s):  
Janusz Majewski

The aim of the paper was to determinate the importance of pollinating insects for food security in Poland. To assess this, there was estimated crop production without pollinators. The information published by the Institute of Horticulture and the Central Statistical Office was used as well as the literature on the subject. The results of the study indicate that insect pollinators play a key role in fruit production, absence of pollinators may result in a crop yield reduction about 80%. In terms of physical availability of food, Polish food security will be preserved even in the absence of insect pollinators. However, at the level of economic availability, food security may not be preserved without such pollinators, in particular in terms of fruit and food security associated with the consumption of properly balanced rations.


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