Xylella lives in the xylem of plants. Insects that feed from the xylem can acquire Xylella and transmit the bacterium to other plants.
Xylella is transmitted by insects to host plants. BRIGIT will investigate this relationship, the species involved and the wider movement of insects within the UK and across countries and continents.
The meadow froghopper, Philaenus spumarius, has been associated with transmission of Xylella in olive in Europe. However, other species are associated with transmission in the Americas, for example the leafhoppers Oncometopia fascialis and Homalodisca vitripennis are important vectors of Xylella in citrus and grapevine, respectively, and therefore other insect vectors could be important if the bacterium became established in new areas.
It is estimated that there may be around 20 xylem-feeding insect species that could vector Xylella in the UK, in particular species of Anoterostemma, Cicadella, Euscelis, Evacanthus and Graphocephala (leafhoppers), and Aphrophora, Cercopis and Neophilaenus (froghoppers). BRIGIT will increase our understanding of their geographical distribution and population structures of these potential vectors.
BRIGIT will expand on what information is already known by developing:
Tools for morphological identification of potential vectors of Xylella to enable their identification by non-specialists
Distribution and plant host range maps of potential Xylella insect vectors across the UK
- UK distribution of leafhoppers and froghoppers
- Plant host range of Philaenus spumarius (in construction)
Genome sequence and genotyping information to assess past and recent migration patterns of Xylella vectors in the UK
- OPENPlantINSECTS.org (in construction)
These resources will build on databases established by the University of Sussex and National Museum Wales through an existing community of entomologists. Taken together these resources will generate knowledge on insect vector distribution and dispersal patterns, to model Xylella dispersal if the bacterium were introduced into the UK. These resources and databases will be accessible online for inspectors, trade bodies, nursery owners, farmers and government bodies to access.
|Potential Xylella vector||Host plants||UK distribution|
|Anoterostemma ivanhofi||Juncus gerardii||South-east Scotland (one record)|
|Cicadella lasiocarpae||Carex & Juncus spp.||Ireland, North Wales|
|Cicadella viridis||Juncus spp.||Ubiquitous|
|Euscelis lineolatus||Grasses||Widespread, not as common as E. lineolatus|
|Evacanthus acuminatus||Herbaceous dicots||Widespread, not as common as E. interruptus|
|Evacanthus interruptus||Herbaceous dicots||Ubiquitous|
|Graphocephala fennahi||Rhododendron ponticum||South-east England, Midlands|
|Aphrophora alni||Trees, esp. Alnus & Salix spp.||Ubiquitous|
|Aphrophora major||Trees, esp. Alnus & Salix spp.||Widespread, not as common as A. alni|
|Aphrophora pectoralis||Trees, esp. Alnus & Salix spp.||Widespread, not as common as A. alni|
|Aphrophora salicina||Trees, esp. Alnus & Salix spp.||Widespread, not as common as A. alni|
|Cercopis vulnerata||Herbaceous dicots||Widespread England & Wales|
|Neophilaenus campestris||Grasses||Widespread, not as common as N. lineatus|
|Neophilaenus exclamationis||Grasses||Widespread, not as common as N. lineatus|
|Neophilaenus longiceps||Grasses||Thames estuary|