Regulated non-quarantine pest Project

An EU funded project for the benefit of the whole EPPO region

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NAME OF THE ORGANISM: Candidatus Phytoplasma pyri (Pear decline mycoplasm) (PHYPPY)


GENERAL INFORMATION ON THE PEST

Name as submitted in the project specification (if different to the preferred name):
 
Pear decline mycoplasm

Pest category:
 
Bacteria


1- Identity of the pest/Level of taxonomic listing:

Is the organism clearly a single taxonomic entity and can it be adequately distinguished from other entities of the same rank?
 
Yes

Is the pest defined at the species level or lower?:
 
Yes

Can listing of the pest at a taxonomic level higher than species be supported by scientific reasons or can species be identified within the taxonomic rank which are the (main) pests of concern?
 
  • Not relevant: Fruits (including hops) sector
Is it justified that the pest is listed at a taxonomic rank below species level?
 
Not relevant

Conclusion:
 
  • Candidate: Fruits (including hops) sector
2 – Status in the EU:
 
Is this pest already a quarantine pest for the whole EU?
 
No

Presence in the EU:
 
Yes

List of countries (EPPO Global Database):
 
Austria (1993); Belgium (2012); Croatia (2010); Czech Republic (2007); France (2003); Germany (2011); Greece (2011); Hungary (2009); Italy (2012); Netherlands (2015); Poland (2002); Portugal (2013); Slovakia (1997); Slovenia (2014); Spain (2014); United Kingdom (2011); United Kingdom/England (2011)

Conclusion:
 
candidate

Justification (if necessary):
 
Data of the presence of this pest on the EU territory are available in EPPO Global Database (https://gd.eppo.int/). This pest is a candidate for the RNQP status according to the IIA2AWG

HOST PLANT N°1: Cydonia (1CYDG) for the Fruits (including hops) sector.


Origin of the listing:
 
IIA2AWG

Plants for planting:
 
Plants intended for planting, other than seeds


3 - Is the pest already listed in a PM4 standard on the concerned host plant?
 
Yes
 
Conclusion:
 
Evaluation continues

 
Justification (if necessary):
 
Decision by the HEWG to continue the evaluation of Candidatus phytoplasma in view of the problematic of vector transmission. As Candidatus phytoplasma pyri is very similar and listed in EPPO PM 4/27 Standard, the same decision is proposed for this pest.

4 - Are the listed plants for planting the main* pathway for the "pest/host/intended use" combination? (*: significant compared to others):
 
Yes
 
Conclusion:
 
Candidate

 
Justification:
 
Cydonia oblonga (quince) is a minor host as it is only poorly colonized by the phytoplasma. Pear trees grafted on quince rootstocks are little affected by Pear decline, as the phytoplasma occurs in a very low titre in the rootstock (PrimaPhacie, 2012). Vector transmission is a pathway. Isolation distances and treatments are available to reduce the severity of the vector in the site of production, however this wouldn't prevent completely the entry of infected vectors in the production site. As the vector normally only flies/moves over shorter distances, keeping the surrounding areas free from PD is also an important measure of control. Experts concluded that plants for planting are a significant pathway compared to other pathways.

5 - Economic impact:

Are there documented reports of any economic impact on the host?
 
Yes

Justification:
 
Quince is described as having poor host properties. Pear trees on quince (Cydonia oblonga) rootstocks are only slightly affected by the disease (Prima Phacie, 2012).

What is the likely economic impact of the pest irrespective of its infestation source in the absence of phytosanitary measures? (= official measures)
 
Minor

Is the economic impact due to the presence of the pest on the named host plant for planting, acceptable to the propagation and end user sectors concerned?
 
Yes

Is there unacceptable economic impact caused to other hosts (or the same host with a different intended use) produced at the same place of production due to the transfer of the pest from the named host plant for planting?
 
No

Conclusion:
 
Not candidate

Justification:
 
Economic impact/damage is very different depending of the varieties and the age of orchards (Older trees tend to have less damage). Infections can disappear after a year, depending on winter conditions. Impact for quince and for pear on quince rootstocks is minor and considered acceptable.


CONCLUSION ON THE STATUS:
 
Disqualified: impact for quince and for pear on quince rootstocks is minor and considered acceptable.


8 - Tolerance level:

Is there a need to change the Tolerance level:
 
Yes

Proposed Tolerance levels:
 
Delisting.

9 - Risk management measures:

Is there a need to change the Risk management measure:
 
Yes

Proposed Risk management measure:
 
Delisting.


REFERENCES:
  • ANSES (2012) Rapport d'expertise collective. Groupe de travail "ARP phytoplasmes des arbres fruitiers". Available at https://www.anses.fr/fr/system/files/SVEG2011sa0137Ra.pdf;
  • EU COM (2016) Recommendation of the Working Group on the Annexes of the Council Directive 2000/29/EC – Section II – Listing of Harmful Organisms as regards the future listing of Candidatus Phytoplasma pyri [Pear decline mycoplasma];
  • Prima phacie (2012) Pest risk assessment for the European Community plant health: A comparative approach with case studies. External scientific report by group of authors: http://www.efsa.europa.eu/fr/supporting/doc/319e.pdf;