Répartition spatiale du risque apicole lié à Vespa velutina en France et en Allemagne

International audienceThe Yellow-legged hornet (Vespa velutina nigrithorax) was accidentally introduced into south-western of France in 2004 and rapidly spread throughout France and neighbouring countries. This insect predator hunts honey bees leading to a hornetmediated beekeeping risk (HBR) with potential mortality of honey bee colonies and important economic costs. However, the spatial distribution of HBR is not yet assessed and is urgently required to formulate suitable management plans in Western Europe. We conducted a two-year citizen science survey in France and Germany to assess the spatial distribution of (1) the hornet and (2) HBR, and to (3) determine the environmental factors involved. A total of 1678 beekeepers participated in the survey. As expected, the hornet was established throughout the French territory, and was mainly detected near the French border in Germany. We found that HBR was substantially lower in Germany than in France. Temperature had a positive effect on both hornet presence and HBR, whereas distance to the introduction point had a negative effect in both France and Germany. These results suggest that the impact of V. velutina on beekeeping is not homogenous across the invasion range and could be reduced on the eastern front due to the continental climate. Taking into account the spatial variability of HBR could help to formulate regionally adapted management plans to limit the impact of V. velutina on biodiversity, human health and economic sectors

data-Dryad

Levels of nectar robbing for 88 plant species in four biogeographical regions with main primary nectar robber

Performance of baited traps used as control tools for the invasive hornet Vespa velutina and their impact on non-target insects

International audienceAbstractThe efficiency and selectiveness of baited traps to control the invasive hornet Vespa velutina is often questioned. Comparative assessments are needed to improve control plans and reduce the impact on honeybees and entomofauna. Our aims were to study the performance of traps and baits, to identify environmental conditions that affect capture rates and to identify the groups of insects affected by trapping. During spring in 2016, three types of trap and baits in a full factorial design were tested. Vespa velutina accounted for less than 1% of all captures, reflecting the low selectiveness of the method. The trap design and its location are decisive aspects to determine the capture rates of V. velutina queens. All trap-bait combinations captured a very high quantity of dipterans, native hymenopterans, and lepidopterans. High capture rates of insect groups which are not common prey of V. velutina reflect that the method constitutes an additional threat on native insects

Predator and pollinator? An invasive hornet alters the pollination dynamics of a native plant

International audienceInvasive vespids are able to disrupt native species assemblages, modify ecological dynamics, and degrade ecosystem services. However, it is often difficult to quantify such effects within invaded ranges, principally due to the complexity of interactions, and a lack of comparative pre-invasion controls. In this study, we thus examine the effects of an invasive hornet, Vespa velutina, upon native species densities and pollination in a major food plant, Hedera hibernica. Using the highly heterogeneous distribution of V. velutina in a coastal area of the northwestern Iberian Peninsula, we assessed the impact of differing hornet abundance on insect diversity, flower visitation frequency, and predator-prey interactions. We then examined resultant effects upon the pollination success of H. hibernica, in the form of fruit and seed set. Our results demonstrated that in areas with high V. velutina abundance, the floral visitation frequencies and durations of insect pollinators were significantly altered. Effects varied widely across insect families, reflected in the differing predation success rates of V. velutina upon various native pollinators, in tandem with competitive exclusion. Interestingly, V. velutina was itself a frequent floral visitor, becoming the most common nectar forager in areas where it was abundant. In spite of this, H. hibernica reproductive success was significantly degraded in these areas, resulting in reduced seed set. As such, V. velutina appears to have multidirectional effects upon pollination services, first as an insect predator, and second as a nectar competitor and pollinator. Crucially, our findings suggest that V. velutina is an inferior pollinator when compared to the native species that it displaces, resulting in a net reduction in pollination efficacy, and hence reproductive success in H. hibernica. This study thus reveals the profound effects of an invasive vespid on native species through both competitive and predatory interactions

Pollinator-flower interactions in gardens during the COVID-19 pandemic lockdown of 2020

During the main COVID-19 global pandemic lockdown period of 2020 an impromptu set of pollination ecologists came together via social media and personal contacts to carry out standardised surveys of the flower visits and plants in gardens. The surveys involved 67 rural, suburban and urban gardens, of various sizes, ranging from 61.18° North in Norway to 37.96° South in Australia, resulting in a data set of 25,174 rows, with each row being a unique interaction record for that date/site/plant species, and comprising almost 47,000 visits to flowers, as well as records of flowers that were not visited by pollinators, for over 1,000 species and varieties belonging to more than 460 genera and 96 plant families. The more than 650 species of flower visitors belong to 12 orders of invertebrates and four of vertebrates. In this first publication from the project, we present a brief description of the data and make it freely available for any researchers to use in the future, the only restriction being that they cite this paper in the first instance. The data generated from these global surveys will provide scientific evidence to help us understand the role that private gardens (in urban, rural and suburban areas) can play in conserving insect pollinators and identify management actions to enhance their potential

Pollinator-flower interactions in gardens during the COVID-19 pandemic lockdown of 2020

During the main COVID-19 pandemic lockdown period of 2020 an impromptu set of pollination ecologists came together via social media and personal contacts to carry out standardised surveys of the flower visits and plants in their gardens. The surveys involved 67 rural, suburban and urban gardens, of various sizes, ranging from 61.18o North in Norway to 37.96o South in Australia and resulted in a data set of 25,174 rows long and comprising almost 47,000 visits to flowers, as well as records of plants that were not visited by pollinators. In this first publication from the project we present a brief description of the data and make it freely available for any researchers to use in the future, the only restriction being that they cite this paper in the first instance. As well as producing a data set that we hope will be widely used in the future, the project helped enormously with the health and mental wellbeing of the participants, a by-product of ecological field work that cannot be over-estimated

Pollinator-flower interactions in gardens during the COVID-19 pandemic lockdown of 2020

During the main COVID-19 pandemic lockdown period of 2020 an impromptu set of pollination ecologists came together via social media and personal contacts to carry out standardised surveys of the flower visits and plants in their gardens. The surveys involved 67 rural, suburban and urban gardens, of various sizes, ranging from 61.18o North in Norway to 37.96o South in Australia and resulted in a data set of 25,174 rows long and comprising almost 47,000 visits to flowers, as well as records of plants that were not visited by pollinators. In this first publication from the project we present a brief description of the data and make it freely available for any researchers to use in the future, the only restriction being that they cite this paper in the first instance. As well as producing a data set that we hope will be widely used in the future, the project helped enormously with the health and mental wellbeing of the participants, a by-product of ecological field work that cannot be over-estimated