Date : 01/02/2012

Impact of the introduced invasive bee-hawking Yellow-legged Hornet on plant-pollinator mutualistic networks

Laboratory
Conservation des Espèces, Restauration et Suivi des Populations
UMR7204, MNHN
55 rue Buffon
CP51
75005 Paris
Website
Main discipline : Ecology
Lab director : Denis Couvet

PhD Supervisor
Frédéric Jiguet
email : Cet e-mail est protégé contre les robots collecteurs de mails, votre navigateur doit accepter le Javascript pour le voir
phone: +33 1 40 79 30 80

Subjects
1.: invasive species
2.: predation
3.: pollination

Tools and Methodologies
1.: modelling mutualistic networks
2.: determining diet with dna barcoding
3.: citizen science to record pollinator communities

Summary of lab's interests
In connection with the missions of the Museum on the future of biodiversity, the CERSP develops researches on the population and community ecology, with various main topics dedicated to rare species conservation, urban ecology, biodiversity scenarios, in connexion with social, economic and politic sciences. The development of volunteer networks (citizen science) to monitor biodiversity is a particularity of our lab. By providing protocols for networks of observers, researchers further analyze these data to characterize the fate of species and community at large spatial and temporal scales, integrating the concept of status indicator communities, generate scenarios detailing the impact of human society on the future of these populations.

Summary of project
Introduced in Aquitaine in 2004, the Asian hornet Vespa velutina nigrithorax then invaded a large part of France, while its expansion continues. Recently, hornet's nests have been found in Region Ile-de-France. A first collaboration between the teams involved in this PhD project modeled the risk of invasion of the species in Europe with niche models (Villemant et al. 2011) and under climate scenarios for 2100 (Barbet-Massin et al. Submitted) . The proposed PhD wishes to study the impact of hornet predation on plant - pollinator mutualistic networks. This involves identifying and quantifying the predation of this exotic hornet on communities of pollinating insects (Beggs et al. 2011), and further modelling the consequences that this predation is likely to have on the functioning and stability of mutualistic networks.
We will study the composition of the pollinator community along a gradient of history of the hornet presence in France, from the introduction site (in Dordogne) to localities beyond the colonization front in the east and north. Prey species will be determined by collecting food pellets that hornet workers bring to the nest, and then proceeding to the genetic identification of taxa by bar-coding. The interactions between plants and pollinators will be sampled locally using the method developed in a citizen science program called 'Spipoll', part of the Vigie-Nature scheme of the MNHN, coupled with captures to enable accurate identification of taxa by entomologists and to gather a DNA reference colelction. Different types of plants will be monitored: wild plants as well as crops such as rapeseed. It will then be possible to compare the architecture of plant - pollinator mutualistic networks along the gradient of invasion (see Fontaine et al. 2006).
A modelling approach will com pare the stability of networks with or without a simulated predation. We will use this information to complete our understanding of changes and instability generated on the architecture of mutualistic networks (Thebault & Fontaine 2010). The integration of crops in the sampled plants will also contribute to evaluate a possible impact on the introduced hornet on crop pollination services. Further work with economists could provide information on potential economical costs if the predation is to depress domestic bee numbers (trade-off between honey production / pollination services facing hornet predation). After an approach considering all pollinators, we plan to focus on the group of Syrphidae, with over 500 species in France. These Diptera, whose larvae strongly regulate aphid populations, are largely consumed by the hornet.
So this is a project largely transverse, which will consolidate the first scientific links established between the UMR 7204 and 7205 on the theme of Asian hornet, which has already resulted in a joint publication in an international journal. References cited in the summary of the project: Barbet-Massin M, Rome Q, Muller F, O Pennard, Villemant C, F Jiguet (submitted). Climate change Increase risk of invasion by the Yellow-legged hornet across Europe. Biological Invasions. Beggs J, Brockerhoff E, Corley J, Kenis K, Masciocchi M, Muller F, Q Rome, Villemant C (2011) Ecological effects and management of invasive Vespidae. In: Roy H, Ware R, Lawson-Handley L, De Clercq P, Wajnberg E (Eds). Arthropod predators and parasitoids invasive: an ecological approach. Biocontrol 56: 505-526. C. Fontaine, I. Dajoz, Mériguet J., Loreau M. (2006). Functional diversity of plant-pollinator interaction webs Enhances the persistence of plant Communities, PLoS Biol., 4 (1): e1, pp. 129-135 Thebault E, Fontaine C (2010) Stability of Ecological Communities and the architecture of mutualistic and Trophic Networks. Science 329: 853-856. Villemant C, Barbet-Massin M, Perrard A, Muller F, O Gargominy, Jiguet F, Q Rome (2011) Predicting the risk invasion by the alien bee-hawking Yellow-legged hornet Vespa velutina nigrithorax across Europe and Other Continents with niche models . Biological Conservation 144, 2142-2150.

Interdisciplinarity of the project
This interdisciplinary project involves two different UMR (7204 and 7205) at the MNHN, agronomists (Jean-Pierre Sarthou, ENSA Toulouse), mathematicians and network modellers (Elisa Thébault, ENS, and Colin Fontaine). By associating competence in field survey by entomologists (hornet and community sampling), citizen science (SPIPOLL scheme), molecular ecology (diet determination) and community modelling in the context of an invasive species threatening pollinators and pollination services, this project is clearly proposing to develop collaboration between different disciplines in biology and agronomy. The ultimate developments with economists would also clearly insert this PhD in a broad multidisciplinary landscape.

Do you have an available funding for this project ?
Potential funds for field and material to be obtained from the labex BCDiv.