Pollinator effectiveness in the mixed-pollination system of a Neotropical Proteaceae, Oreocallis grandiflora

In pollination systems with a diverse community of floral visitors, qualitative and quantitative variations in pollination effectiveness can lead to a system in which higher effectiveness results from the synergetic contribution of multiple pollinators. By employing a series of field and laboratory experiments in the south Andes of Ecuador, we compared the effectiveness of hummingbirds and nocturnal mammals visiting Oreocallis grandiflora, an Andean member of the Proteaceae. Pollinator effectiveness was measured with a quantitative component that assessed visitation rates to inflorescences and number of contacted stigmas per visit, and with a qualitative component that counted the number of deposited pollen grains in stigmas. Effectiveness estimates were complemented with controlled pollination experiments that contrasted fruit and viable seed set among flowers exposed to either diurnal or nocturnal pollination, self-pollinated flowers, and a control group with flowers exposed to naturally occurring pollination. Four species of hummingbirds and two species of nocturnal mammals visited the flowers of O. grandiflora. Hummingbirds outperformed nocturnal mammals in the quantitative components of pollination, while mammals were more effective than hummingbirds in the qualitative component. Pollination success was higher for the control group than for the other treatments, while hummingbirds and mammals performed similarly. Our findings suggest a case of functional complementarity in pollination: hummingbirds’ quantitative effectiveness complements nocturnal mammals’ qualitative effectiveness. Furthermore, our study demonstrates that pollination success in plants can be greater when flowers are visited by the whole diversity of pollinators.

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Why so many flowers? A preliminary assessment of mixed pollination strategy enhancing sexual reproduction of the invasive <i>Acacia longifolia</i> in Portugal

Web Ecology ◽

10.5194/we-18-47-2018 ◽

2018 ◽

Vol 18 (1) ◽

pp. 47-54 ◽

Cited By ~ 1

Author(s):

Manuela Giovanetti ◽

Margarida Ramos ◽

Cristina Máguas

Keyword(s):

Invasive Plant ◽

Seed Set ◽

Pollen Grains ◽

Striking Difference ◽

Pollination Syndromes ◽

Pollination Success ◽

Relative Contribution ◽

Acacia Longifolia ◽

Exclusion Experiments ◽

Pollination Strategy

Abstract. Acacia longifolia, a native legume from Australia, has been introduced in many European countries and elsewhere, thus becoming one of the most important global invasive species. In Europe, its flowering occurs in a period unsuitable for insect activity: nonetheless it is considered entomophilous. Floral traits of this species are puzzling: brightly coloured and scented as liked by insects, but with abundant staminate small-sized flowers and relatively small pollen grains, as it is common in anemophilous species. Invasion processes are especially favoured when reshaping local ecological networks, thus the interest in understanding pollination syndromes associated with invasive plant species that may facilitate invasiveness. Moreover, a striking difference exists between its massive flowering and relatively poor seed set. We introduced a novel approach: first, we consider the possibility that a part of the pollination success is carried on by wind and, second, we weighted the ethological perspective of the main pollinator. During the flowering season of A. longifolia (February–April 2016), we carried on exclusion experiments to detect the relative contribution of insects and wind. While the exclusion experiments corroborated the need for pollen vectors, we actually recorded a low abundance of insects. The honeybee, known pollinator of acacias, was relatively rare and not always productive in terms of successful visits. While wind contributed to seed set, focal observations confirmed that honeybees transfer pollen when visiting both the inflorescences to collect pollen and the extrafloral nectaries to collect nectar. The mixed pollination strategy of A. longifolia may then be the basis of its success in invading Portugal's windy coasts.

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Pollination by nectar-foraging thynnine wasps in the endangered Caladenia arenaria and Caladenia concolor (Orchidaceae)

Australian Journal of Botany ◽

10.1071/bt19033 ◽

2019 ◽

Vol 67 (7) ◽

pp. 490 ◽

Cited By ~ 5

Author(s):

Noushka Reiter ◽

Björn Bohman ◽

Marc Freestone ◽

Graham R. Brown ◽

Ryan D. Phillips

Keyword(s):

Threatened Species ◽

Single Species ◽

Orchid Species ◽

Late Afternoon ◽

Nectar Foraging ◽

Pollinator Species ◽

Floral Visitors ◽

Pollination Strategy ◽

Pollination Systems

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.

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Breeding biology and distyly in Palicourea rigida H. B. & K. (Rubiaceae) in the Cerrados of Central Brazil

Acta Botanica Brasilica ◽

10.1590/s0102-33062010000300012 ◽

2010 ◽

Vol 24 (3) ◽

pp. 686-696 ◽

Cited By ~ 15

Author(s):

Adriana de Oliveira Machado ◽

Ana Palmira Silva ◽

Helder Consolaro ◽

Mariluza A. Granja e Barros ◽

Paulo Eugênio Oliveira

Keyword(s):

Reproductive Success ◽

Fruit Set ◽

Pollen Grains ◽

Floral Biology ◽

Nectar Production ◽

Central Brazil ◽

Palicourea Rigida ◽

Floral Visitors ◽

Compatible Pollen ◽

Incompatibility Reactions

Distyly is a floral polymorphism more common among the Rubiaceae than in any other angiosperm group. Palicourea rigida is a typically distylous species of the Rubiaceae widely distributed in the Brazilian Cerrados. This work aimed to study the floral biology and breeding system of P. rigida in order to verify if there wasasymmetry between floral morphs. The work was carried out at Fazenda Água Limpa, Brasília-DF, from 1993 to 1995; and at Serra Caldas Novas State Park-Goias and in Clube Caça e Pesca Itororó de Uberlândia-Minas Gerais in 2005 and 2006. Density, height and pin/thrum ratio were assessed for flowering individuals in all areas. Plants were investigated for differences in floral morphology, nectar production, reproductive success and site of self incompatibility reactions. Blooming period was long and concentrated during the rains. Flowers were clearly distylous and with reciprocal herkogamy. They produced nectar and lasted for a single day. In spite of differences in density and height, populations were mostly isoplethic. Nectar production varied in volume and concentration but the differences could not be associated with floral morphs. The species is self-incompatible but reproductive success was always high and independent of floral morphs. There were differences in the site of incompatibility barriers between floral morphs, which were similar to those observed for other Rubiaceae. The main floral visitors and pollinators were the hummingbirds Colibri serrirostris and Eupetomena macroura. High fruit-set indicates that the pollinators transported enough compatible pollen grains between floral morphs, despite their territorial behavior.

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Pollinator effectiveness of a specialist bee exploiting a generalist plant—tracking pollen transfer by Heriades truncorum with quantum dots

Apidologie ◽

10.1007/s13592-019-00700-0 ◽

2019 ◽

Vol 51 (2) ◽

pp. 201-211 ◽

Cited By ~ 1

Author(s):

Sabine Konzmann ◽

Margareta Kluth ◽

Deniz Karadana ◽

Klaus Lunau

Keyword(s):

Quantum Dots ◽

Reproductive Success ◽

Pollen Germination ◽

Pollen Grains ◽

Pollen Transfer ◽

Pollinator Effectiveness ◽

Flower Constancy ◽

Single Visit ◽

Heriades Truncorum ◽

Open Control

AbstractHeriades truncorum (Megachilidae) is a specialist bee that forages on Asteraceae and collects pollen by tapping its abdomen on pollen-presenting florets which places the grains directly in the ventral scopa. We tracked pollen transfer by female H. truncorum between conspecific inflorescences of Inula ensifolia and Pulicaria dysenterica by labelling pollen with quantum dots. On average, bees transferred 31.14 (I. ensifolia) and 9.96 (P. dysenterica) pollen grains from the last visited inflorescence, 39% and 45% of which were placed on receptive styles. Pollen germination ratio is significantly lower for inflorescences of P. dysenterica visited by one H. truncorum (0.13%) compared with open control inflorescences (0.51%), which suggests that the bees mainly transfer self-pollen of these self-incompatible plants. Thus, a single visit by H. truncorum does not grant the plant high reproductive success, but the bees’ abundance and flower constancy might reduce this disadvantage.

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Nucleopolyhedrovirus infection in obliquebanded leafroller (Lepidoptera: Tortricidae)

The Canadian Entomologist ◽

10.4039/ent134303-3 ◽

2002 ◽

Vol 134 (3) ◽

pp. 303-309 ◽

Cited By ~ 2

Author(s):

I. Pronier ◽

J. Paré ◽

J-C Wissocq ◽

C. Vincent

Keyword(s):

Fat Body ◽

Larval Mortality ◽

Adult Emergence ◽

Control Group ◽

Choristoneura Rosaceana ◽

Obliquebanded Leafroller ◽

Naturally Occurring ◽

The Family ◽

Microscopic Studies ◽

Occlusion Bodies

AbstractA virus isolated from obliquebanded leafroller, Choristoneura rosaceana (Harris), larvae collected in an apple, Malus domestica Borkh. (Rosaceae), orchard of Saint-Joseph-du-Lac (Quebec, Canada) was studied. Microscopic studies revealed that it was a uninucleocapsid nucleopolyhedrovirus from the family Baculoviridae. Larval mortality was approximately 75% (0% mortality in control group) in larvae infected as third instars immersed in a suspension of 1.7 × 108 occlusion bodies/mL. The average time for larval mortality was 23 ± 3 d after treatment. The majority (95.5%) of infected larvae died as fifth or sixth instars. Infection was observed primarily in fat body cells, and occasionally in the tracheal matrix and epidermis. Mean larval development time of infected larvae surviving to pupae was 20 ± 3 d, significantly greater than the 18 ± 3 d observed in control larvae. Adult emergence was significantly lower in pupae of treated larvae (73.6%) than in the control group (93.5%). Our work constitutes the first baseline study of naturally occurring virus of the obliquebanded leafroller.

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Pollen adaptation to ant pollination: a case study from the Proteaceae

Annals of Botany ◽

10.1093/aob/mcaa058 ◽

2020 ◽

Vol 126 (3) ◽

pp. 377-386 ◽

Cited By ~ 2

Author(s):

Nicola Delnevo ◽

Eddie J van Etten ◽

Nicola Clemente ◽

Luna Fogu ◽

Evelina Pavarani ◽

...

Keyword(s):

Seed Set ◽

Germination Rate ◽

Pollen Grains ◽

Relative Effect ◽

The Other ◽

Pollen Load ◽

Pollination Services ◽

Ant Pollination ◽

Negative Effect ◽

Floral Visitors

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.

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Effects of ants on pollinator performance in a distylous pericarpial nectary-bearing Rubiaceae in Brazilian Cerrado

Sociobiology ◽

10.13102/sociobiology.v67i2.4846 ◽

2020 ◽

Vol 67 (2) ◽

pp. 173

Author(s):

Bruno De Sousa-Lopes ◽

Eduardo Soares Calixto ◽

Helena Maura Torezan-Silingardi ◽

...

Keyword(s):

Indirect Cost ◽

Field Study ◽

Brazilian Cerrado ◽

Effective Protection ◽

Cross Pollination ◽

Floral Phenology ◽

Floral Visitors ◽

Pollinator Performance ◽

Pollination Systems

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.

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The importance of fruit set, fruit abortion, and pollination success in fruit production of teak (Tectona grandis)

Canadian Journal of Forest Research ◽

10.1139/x10-160 ◽

2010 ◽

Vol 40 (11) ◽

pp. 2204-2214 ◽

Cited By ~ 9

Author(s):

E. R. Palupi ◽

J. N. Owens ◽

S. Sadjad ◽

Sudarsono ◽

D. D. Solihin

Keyword(s):

Fruit Set ◽

Pollen Viability ◽

Pollen Grains ◽

Tectona Grandis ◽

Seed Orchard ◽

Fruit Production ◽

Time Of Day ◽

Natural Forests ◽

Pollination Success ◽

Fruit Abortion

Teak ( Tectona grandis L.) is believed to have been introduced from India 400–500 years ago and there appear to be no old-growth natural forests. However, Indonesia has many teak plantation forests and 40%–50% of seeds for reforestation come from seed orchards and the remainder from plantations. In both, flower and fruit abortion results in low fruit set and thus seed production. We investigated flower and fruit development in a clonal seed orchard in East Java in 1999 and 2001 using cross- and open-pollinated trees. The rates of abortion using cross-pollinations showed a similar pattern but were lower than for open-pollinations. The highest rate of abortion in cross- and open-pollinations was during pollination and fertilization, ranging 11%–23% and 31%–32%/day, respectively, less during fruit initiation (5%–6% and 6%–8%/day) and the lowest was during fruit maturation (<0.5%/day). Cross-pollinations increased fruit production by 10-fold compared with open-pollinations. About 30% of flowers were pollinated with an average of five pollen grains per stigma in open-pollinations. Pollen viability varied among clones and time of day but was not affected by position of flowers in an inflorescence. We conclude that low pollination success and low pollen viability are major causes for low fruit production in teak and are related to insect pollinators.

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The pollination ecology of the late-successional tree, Oroxylum indicum (Bignoniaceae) in Thailand

Journal of Tropical Ecology ◽

10.1017/s026646740800521x ◽

2008 ◽

Vol 24 (05) ◽

pp. 477-484 ◽

Cited By ~ 28

Author(s):

Tuanjit Srithongchuay ◽

Sara Bumrungsri ◽

Ekapong Sripao-raya

Keyword(s):

Plant Species ◽

Fruit Set ◽

Pollen Grains ◽

Pollen Load ◽

Pollination Success ◽

Oroxylum Indicum ◽

Tropical Plant ◽

Fruit Bat ◽

Highly Sensitive ◽

Multiple Species

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.

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Pollination success in three tropical dry forest orchid species from Mexico: insights from floral display, visitation rates, and flower micromorphology

Botanical Sciences ◽

10.17129/botsci.2785 ◽

2021 ◽

Vol 1 (1) ◽

Author(s):

Yazmín M. Miranda-Molina ◽

Edgar J. González ◽

Judith Márquez-Guzmán ◽

Jorge Meave ◽

Eduardo A. Pérez García

Keyword(s):

Tropical Dry Forest ◽

Dry Forest ◽

Floral Display ◽

Linear Modeling ◽

Deposition Rates ◽

Pollination Success ◽

Visitation Rates ◽

Orchid Pollination ◽

Floral Micromorphology ◽

Floral Visitors

Background: Despite long-lasting efforts to disentangle the drivers of orchid pollination, pollination success in tropical dry forest orchids remains largely unknown. Questions and hypothesis: How successful are pollination in three tropical dry forest orchids? How is pollination influenced by floral display and floral rewards (as suggested by floral micromorphology)? We hypothesized a positive effect of floral display on pollinia removal and deposition rates. Studied species: Barkeria whartoniana (C. Schweinf.) Soto Arenas, Clowesia dodsoniana E. Aguirre, and Cyrtopodium macrobulbon (La Llave & Lex.) G.A. Romero & Carnevali. Study site and dates: Nizanda (Oaxaca), Mexico; flowering periods of 2013 and 2014. Methods: We calculated pollinia removal and deposition rates, identified floral visitors and analyzed flower microstructure to search for structures potentially producing rewards. Floral display was measured through number of open flowers, and number and length of inflorescences, and its effect on pollination success was assessed through linear modeling. Results: Pollinia removal rates were higher than deposition rates, and floral display was related to pollination success in C. dodsoniana only. Visitation rates were low for the three species and most visitors were not true pollinators. The three species possess potentially secreting structures, but for B. whartoniana and C. macrobulbon these rewards are likely part of the pollinator deception mechanism. Conclusions: The generalized low pollination success implies the need for high population densities of both interacting parts. We emphasize the need for integrated evaluations of different aspects of the plant-pollinator interaction.

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