TY - JOUR
T1 - Susceptibility of Phoenix roebelenii to Xylella fastidiosa
AU - Rossi, Vittorio
AU - Jeger, Michael
AU - Bragard, Claude
AU - Caffier, David
AU - Chatzivassiliou, Elisavet
AU - Dehnen Schmutz, Katharina
AU - Gilioli, Gianni
AU - Grégoire, Jean Claude
AU - Jaques Miret, Josep Anton
AU - Macleod, Alan
AU - Navajas Navarro, Maria
AU - Niere, Bjoern
AU - Parnell, Stephen
AU - Potting, Roel
AU - Rafoss, Trond
AU - Urek, Gregor
AU - Van Bruggen, Ariena
AU - Van Der Werf, Wopke
AU - West, Jonathan
AU - Winter, Stephan
AU - Tramontini, Sara
AU - Andueza, Miren
AU - Candresse, Thierry
PY - 2016
Y1 - 2016
N2 - Following a request from the European Commission, the EFSA Plant Health Panel analysed a dossier
submitted by Costa Rica Authorities to reach a conclusion on the host status of Phoenix roebelenii for
Xylella fastidiosa. The Panel wishes first to stress the difficulties faced in providing compelling evidence
for the non-susceptibility status of any particular plant species. The Panel acknowledges that the listing
of P. roebelenii as a host of X. fastidiosa rests on a single report from California. Because isolation of
X. fastidiosa from some hosts can be difficult, the Panel considers that the failure to isolate
X. fastidiosa from P. roebelenii cannot be used to totally discard the detection of X. fastidiosa by ELISA
and PCR. The Panel concludes that the detection of X. fastidiosa by two independent techniques
provides sufficient evidence, although not totally conclusive, for the listing of P. roebelenii as a
X. fastidiosa host plant. Concerning the survey data provided in the Costa Rican dossier, the
Panel wishes to stress that such surveys cannot demonstrate the non-host status but can only provide
a probability bound, upper estimate of the proportion of infected plants in the field. In the present
case, and assuming all survey parameters to be optimal, the 95% confidence incidence threshold
obtained is 0.2%, leaving the possibility that close to 25,000 P. roebelenii plants could be infected but
undetected in the country. Accepting a scenario of local, non-systemic infection of P. roebelenii by
X. fastidiosa would further increase uncertainties. In addition, the absence of data on the vector
infection pressure further affects the ability to derive meaningful information on the P. roebelenii host
status from the survey data. Appropriately conducted mechanical and/or vector-mediated inoculation
experiments are critical to reach a more solid conclusion on the X. fastidiosa host status of
P. roebelenii.
AB - Following a request from the European Commission, the EFSA Plant Health Panel analysed a dossier
submitted by Costa Rica Authorities to reach a conclusion on the host status of Phoenix roebelenii for
Xylella fastidiosa. The Panel wishes first to stress the difficulties faced in providing compelling evidence
for the non-susceptibility status of any particular plant species. The Panel acknowledges that the listing
of P. roebelenii as a host of X. fastidiosa rests on a single report from California. Because isolation of
X. fastidiosa from some hosts can be difficult, the Panel considers that the failure to isolate
X. fastidiosa from P. roebelenii cannot be used to totally discard the detection of X. fastidiosa by ELISA
and PCR. The Panel concludes that the detection of X. fastidiosa by two independent techniques
provides sufficient evidence, although not totally conclusive, for the listing of P. roebelenii as a
X. fastidiosa host plant. Concerning the survey data provided in the Costa Rican dossier, the
Panel wishes to stress that such surveys cannot demonstrate the non-host status but can only provide
a probability bound, upper estimate of the proportion of infected plants in the field. In the present
case, and assuming all survey parameters to be optimal, the 95% confidence incidence threshold
obtained is 0.2%, leaving the possibility that close to 25,000 P. roebelenii plants could be infected but
undetected in the country. Accepting a scenario of local, non-systemic infection of P. roebelenii by
X. fastidiosa would further increase uncertainties. In addition, the absence of data on the vector
infection pressure further affects the ability to derive meaningful information on the P. roebelenii host
status from the survey data. Appropriately conducted mechanical and/or vector-mediated inoculation
experiments are critical to reach a more solid conclusion on the X. fastidiosa host status of
P. roebelenii.
KW - Costa Rica
KW - host plant
KW - sampling
KW - survey
KW - Costa Rica
KW - host plant
KW - sampling
KW - survey
UR - http://hdl.handle.net/10807/93738
U2 - 10.2903/j.efsa.2016.4600
DO - 10.2903/j.efsa.2016.4600
M3 - Article
VL - 14
SP - 1
EP - 11
JO - EFSA Journal
JF - EFSA Journal
SN - 1831-4732
ER -