Heterogeneous chemical profiles of Vespa velutina nigrithorax alarm pheromone.

Berville L, Lucas C, Haouzi M, Khalil A, Gévar J, Bagnères A-G, Darrouzet E

As major communication signals, pheromones have long been studied.  In colonial organisms such as social insects, volatile compounds play a crucial role in interspecific interactions by helping regulate colony behavior. In certain circumstances, it is desirable to detect or suppress insect populations, like invasive species. Management’s techniques have included lures, baits, and traps. Synthetic or natural insect pheromones are in wide use around the world for pest control. Such molecules can be used for pest management strategies. Because of their success in establishment and ecological dominance, Asian hornets are considered as severe economic and ecological pests. Native to Southeast Asia Vespa velutina nigrithorax has spread throughout Europe. To clarify the composition of the species’ alarm pheromone and to assess differences in chemical profiles among queens, foundresses, gynes, and workers, we employed gas chromatography-mass spectrometry. 26 compounds were identified in the venom gland (chain lengths: C8 to C12), the organ that produces the alarm pheromone. Venom gland composition differed quantitatively among the females (workers, gynes, and queens). These results could help the development of a future pheromone-based trap to control this invasive hornet species.

Pinpointing the best thermic system to instantaneously immobilize the invasive Asian hornet Vespa velutina nigrithorax.

Ruiz-Christi, I., Berville, L., Darrouzet, E
DOI : 10.13140/RG.2.2.23689.47205


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The Asian yellow-legged hornet, Vespa velutina nigrithorax (Hymenoptera: Vespidae, Lepeletier 1836) is an Indo-China species, which has been unintentionally introduced in France and is spreading in many areas of the world. This species, which is considered as Union concern in Europe, presented a major impact on beekeeping activities, mostly by preying honey bees (Apis mellifera) at the beehive entrances. Currently, none of the control methods developed are simultaneously biofriendly and efficient. With the ambition in providing an eco-selective approach to destroy V. velutina nests, Apis cerana behavior was taken as an example. Indeed, in their native area, A. cerana presents an effective collective defense mechanism against hornet’s attacks: the “heat ball”. In this study, diverse temperatures and thermal systems were tested, in a laboratory, against Vespa velutina individuals according to their sex, castes and developmental stages. The thermal resilience of all individuals decreased significantly with the increase in temperatures. Comparatively, hornets died faster went faced with a gradual rise in temperaturesthan when directly exposed to a set temperature; larvae seem to be the most resistants. Steam water seems to be the most suitable and promising technique to quickly eradicate hornets as they all succumbed before 13 seconds, and therefore could be a good candidate for a green nest control method.

Self-organized subterranean architectures, wood excavation dynamics and nest constructions in two Reticulitermes termite species

Berville, L., Darrouzet, E
DOI :10.13140/RG.2.2.13250.53449

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Composed of networks of tunnels and chambers, collective constructions are marvels of complexity. Nevertheless, as nests are built in the soil or within pieces of wood, studying subterranean construction is problematic without using invasive techniques. For those reasons, nest-building dynamics and wood consumption dynamics are largely unknown for Reticulitermes subterranean termite species. Nowadays, using computerized tomography (CT) scans, it is possible to reconstruct a 3D structure via a series of 2D images, without harm for the inhabitants. Using CT scans and imaging software, we observed nest creation, constructions, and architecture of two subterranean termite species. We monitor, over a 10 month period, the nests’ growth built by R. grassei, a species native to Europe, and R. flavipes, an invasive species introduced from North America. Doing so, we wanted to know whether the construction of the nest could participate to the invasive success of R. flavipes. Although the two species displayed some similarities, only R. flavipes built interior structures with soil particles. R. flavipes seemed to have the ability to generate and modify interior architectural structures such as pillars, ceilings/ floors, tunnels, and inner/outer walls. Some of these structures changed over time and thus might play a role in the trade-off between wood consumption, colony protection, and environmental homeostasis. This study underscores the utility of CT scans as a non-invasive technique for following wood consumption and nest architecture in termites over time.

Restauration écologique de l’île de Bagaud par éradications simultanées d’espèces exotiques envahissantes et conséquences sur la biodiversité insulaire.
Braschi J, Ponel P, Cottaz C, Amy E, Passetti A, Aboucaya A, Affre L, Allegre A, Barcelo A, Berger G, Berville L, Bigeard N, Bonnaud E, Brousset L, Chenot J, De Meringo H, Fourcy D, Gauthier J, Gillet P, Le Quilliec P, Limouzin Y, Lorvelec O, Medail F, Meunier J-Y, Pascal M, Pascal Ma, Riffet I, Ruffino I, Vidal E, Santelli C, Fadda S & Buisson E

Restauration écologique de l'île de Bagaud (réserve intégrale du Parc national de Port Cros) par éradications simultanées d'espèces exotiques envahissantes et conséquences sur la biodiversité insulaire.
Braschi J, Ponel P, Cottaz C, Amy E, Aboucaya A, Affre L, Allegre A, Barcelo A, Berger G, Berville L, Bigeard N, Bonnaud E, Brousset L, Chenot J, Passetti A, De Meringo H, Fourcy D, Gauthier J, Gillet P, Le Quilliec P, Limouzin Y, Lorvelec O, Medail F, Meunier J-Y, Pascal M, Riffet I, Ruffino I, Vidal E, Santelli C, Fadda S & Buisson E

Conséquences de l’éradication simultanée de deux espèces invasives sur la biodiversité de la réserve intégrale de Bagaud (Parc national de Port Cros): Bilan 5 ans après éradication.
Braschi J, Ponel P, Cottaz C, Amy E, Passetti A, Aboucaya A, Affre L, Allegre A, Barcelo A, Berger G, Berville L, Bigeard N, Bonnaud E, Brousset L, Chenot J, De Meringo H, Fourcy D, Gauthier J, Gillet P, Lequilliec P, Limouzin Y, Lorvelec O, Medail F, Meunier J-Y, Pascal M, Pascal Ma, Riffet F, Ruffino L, Santelli C, Vidal E, Fadda S & Buisson E

Restauration écologique de l'île de Bagaud (réserve intégrale du Parc national de Port Cros) par éradications simultanées d'espèces exotiques envahissantes et conséquences sur la biodiversité insulaire.
Braschi J, Ponel P, Cottaz C, Amy E, Aboucaya A, Affre L, Allegre A, Barcelo A, Berger G, Berville L, Bigeard N, Bonnaud E, Brousset L, Chenot J, Passetti A, De Meringo H, Fourcy D, Gauthier J, Gillet P, Le Quilliec P, Limouzin Y, Lorvelec O, Medail F, Meunier J-Y, Pascal M, Riffet I, Ruffino I, Vidal E, Santelli C, Fadda S & Buisson E

Éradications simultanées du rat noir (Rattus rattus) et des griffes de sorcière (Carpobrotus spp.) sur l'île de Bagaud (Parc national de Port-Cros, Provence, France) : conséquences sur les communautés d'Arthropodes
Braschi J, Ponel P, Krebs E, Jourdan H, Passetti A, Barcelo A, Berville L, Le Quilliec P, Lorvelec O, Matocq A, Meunier J-Y, Oger P, Sechet E & VIDAL E

Braschi J, Ponel P, Krebs E, Jourdan H, Passetti A, Berville L, Judson M, Matocq A, Oger P, Séchet E & Vidal E - 2015

Restauration des communautés  d'Arthropodes dans le contexte d'une éradication multi-invasives : Le cas de  L’île de BAGAUD (PARC NATIONAL DE PORT-CROS) après éradication de  Rattus rattus et de Carpobrotus spp