Xylella fastidiosa is a xylem bacterium native to the Americas, known to be responsible for example of the Pierce’s disease that affects Citrus species in Brazil or the Californian vineyards. In Europe, it has been detected for the first time in 2013 in Italy killing thousands of olive trees in the Puglia region and on Corsica in 2015. X. fastidiosa is propagated by insect vectors from the order of the Auchenorrhyncha, and more specifically by species feeding on the xylem where the bacterium develops. It seems that on Corsica the main vector is Philaenus spumarius (Aphrophoridae), a species with a worldwide distribution able to use hundreds of different host-plants. However on Corsica our preliminary results indicate that larvae and adults of P. spumarius are often found on the rockrose, Montpellier cistus (Cistus monspeliensis, Myrtaceae). Though the ecology of P. spumarius is relatively well known in continental Europe, it’s not the case on Corsica where many ecological and biological information are not known.
The aim of this traineeship is to study the bio-ecology of P. spumarius, especially the alimentary preferences of the adults and the oviposition sites (host-plants). On Corsica, X. fastidiosa has been detected in about twenty different plants species. P. spumarius is known to be highly polyphagous at the adult stage. However on Corsica, this species is mainly observed on Cistus monspeliensis in autumn. Choice tests will be performed in order to determine the alimentary preferences of the adults of P. spumarius. The capacity of the adults to feed on other plants than C. monspeliensis will be also tested to have a better understanding of the bacteria transmission. In order to show that host-plant preference is achieved by the females during the oviposition rather than by migration of the larvae, oviposition censuses on different host-plants will be performed along transects.
Activities during the traineeship
- Set up of experimental designs in the field or under laboratory conditions.
- Preference tests of host-plants by adults of P. spumarius during multiple choice experiments under laboratory conditions.
- Adult feeding experiments on different host-plants using vital stains under laboratory conditions.
- Oviposition censuses on different host-plants along transects in the field.