Search results for "Pollinator"
showing 10 items of 95 documents
Floral scent in a sexually deceptive Ophrys orchid: from headspace collections to solvent extractions
2018
Sexually deceptive orchid flowers use visual, tactile and olfactory cues of female insects in order to attract males of one or a few closely related species as pollinators. Ophrys L. is the most species-rich genus of sexually deceptive orchids in the Mediterranean Basin. Despite Ophrys pollinated by Andrena male bees use alkanes and mainly alkenes with specific double-bond positions as key signals that trigger pseudocopulatory behavior, some volatile organic compounds (VOCs) with low molecular weight were found as long-range attractants non-eliciting copulatory behavior. Since floral scents in Ophrys have been extensively studied by solvent extractions here we aimed to understand which flor…
Using metabarcoding to reveal and quantify plant-pollinator interactions.
2016
AbstractGiven the ongoing decline of both pollinators and plants, it is crucial to implement effective methods to describe complex pollination networks across time and space in a comprehensive and high-throughput way. Here we tested if metabarcoding may circumvent the limits of conventional methodologies in detecting and quantifying plant-pollinator interactions. Metabarcoding experiments on pollen DNA mixtures described a positive relationship between the amounts of DNA from focal species and the number of trnL and ITS1 sequences yielded. The study of pollen loads of insects captured in plant communities revealed that as compared to the observation of visits, metabarcoding revealed 2.5 tim…
Training experiments with Bombus terrestris and Apis mellifera on artificial ‘ Salvia ’ flowers
2016
Abstract Many bee flowers demand physical force from their pollinators. An example is Salvia with lever-like anthers restricting access to nectar. Though the needed force is generally low, it is largely unknown how far even low forces affect flower preference and foraging behaviour of bees. In the present paper, we introduce a method to measure the response of bees to a force mechanism. We explain the construction of artificial flowers mimicking the lever mechanism of a Salvia flower and the procedure to train honeybees and bumblebees to the models. We document the behaviour of the bees on models without barriers and on those with low forces aiming at the same time to determine the bees’ se…
Potential impact of genetically modified Lepidoptera-resistant Brassica napus in biodiversity hotspots: Sicily as a theoretical model
2018
The general increase of the cultivation and trade of Bt transgenic plants resistant to Lepidoptera pests raises concerns regarding the conservation of animal and plant biodiversity. Demand for biofuels has increased the cultivation and importation of oilseed rape (Brassica napus L.), including transgenic lines. In environmental risk assessments (ERAs) for its potential future cultivation as well as for food and feed uses, the impact on wild Brassicaeae relatives and on non-target Lepidoptera should be assessed. Here we consider the potential exposure of butterflies as results of possible cultivation or naturalization of spilled seed in Sicily (Italy). Diurnal Lepidoptera, which are pollinat…
Invasive bees and their impact on agriculture
2020
Fil: Aizen, Marcelo A. Universidad Nacional del Comahue. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Fil: Aizen, Marcelo A. Consejo Nacional de Investigaciones Científicas y Técnica. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Fil: Arbetman, Marina P. Universidad Nacional del Comahue. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Fil: Arbetman, Marina P. Consejo Nacional de Investigaciones Científicas y Técnica. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Fil: Chacoff, Natacha P. Universidad Nacional de Tucumán. Instituto de Ecología Regional; Argentina. Fil: Chalcoff, Vanin…
Pollination biology in Roepera (Zygophyllaceae): How flower structure and shape influence foraging activity
2019
The foraging behavior of bees is a complex phenomenon that depends on numerous physical features of flowers. Of particular importance are accessibility of floral rewards, floral proportions, symmetry and orientation. The flowers of Roepera are characterized by the presence of staminal scales (SS), which play an important role in nectar protection. We studied two species of Roepera with different symmetry and flower orientation, which are mainly visited by honeybees (Apis mellifera). We aimed to show how the foraging behavior of honey bees is affected by the function of SS, floral symmetry and orientation. The foraging behavior was documented by video photography. Handling time, access to ne…
Influence of brood temperature and hygrometry variations on the development of the honey bee ectoparasite Varroa jacobsoni (Mesostigmata : Varroidae)
1990
The influence of different temperatures (from 26 to 39.5°C) and relative humidities (40 and 70%) on the development of Varma jacobsoni (Oudemans) was studied by placing newly capped and parasitized worker bee broods into thermostatically controlled chambers. In one set of experiments the temperature was kept constant, and in the second set, the parasitized worker broods were placed at a temperature of 40,41, or 42°C for a time varying from 0 to 24 h and then returned to 32.5°C. The optimal temperature for development of the mites was between 32.5 and 33.4°C, which corresponds to the brood temperature of Apis mellifera L. Above 36.5°C, reproduction of varroa females was significantly reduced…
Time after time: flowering phenology and biotic interactions.
2007
International audience; The role of biotic interactions in shaping plant flowering phenology has long been controversial; plastic responses to the abiotic environment, limited precision of biological clocks and inconsistency of selection pressures have generally been emphasized to explain phenological variation. However, part of this variation is heritable and selection analyses show that biotic interactions can modulate selection on flowering phenology. Our review of the literature indicates that pollinators tend to favour peak or earlier flowering, whereas pre-dispersal seed predators tend to favour off-peak or later flowering. However, effects strongly vary among study systems. To unders…
Fine-scale spatial genetic structure and gene dispersal in Silene latifolia
2010
Plants are sessile organisms, often characterized by limited dispersal. Seeds and pollen are the critical stages for gene flow. Here we investigate spatial genetic structure, gene dispersal and the relative contribution of pollen vs seed in the movement of genes in a stable metapopulation of the white campion Silene latifolia within its native range. This short-lived perennial plant is dioecious, has gravity-dispersed seeds and moth-mediated pollination. Direct measures of pollen dispersal suggested that large populations receive more pollen than small isolated populations and that most gene flow occurs within tens of meters. However, these studies were performed in the newly colonized rang…
Artificial germination activation of Dialium corbisieri by imitation of ecological process.
2013
11 pages; International audience; Species of the gender Dialium commonly are trees found in Central African rainforests. They produce tasty sugary fruits, feeding numerous frugivores, but are, despite their valuable nutritional value, rarely exploited by humans. A potential reason for this could be the complexity of symbiotic dependence between trees and pollinators, germination activators, and dispersers causing problems in ancestral and contemporary domestication. We investigated Dialium corbisieri reproduction in the Democratic Republic of the Congo, Bandundu Province. Here we give a key for an artificial activation of germination of these trees ecologically adapted to the digestive syst…