NAME OF THE ORGANISM: Aonidiella citrina (AONDCI)
GENERAL INFORMATION ON THE PEST
Name as submitted in the project specification (if different to the preferred name):
Pest category:
Insecta
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: Ornamental sector
Is it justified that the pest is listed at a taxonomic rank below species level?
Not relevant
Conclusion:
- Candidate: Ornamental sector
Justification (if necessary):
Citrus species are considered the most common hosts, including C. limon, C. paradisi, C. reticulata sensu stricto and C. sinensis. Other hosts, such as Citrofortunella microcarpa, Citroncirus, Fortunella and Poncirus trifoliata are reported as being attacked by the pest, but not as often or not as severely as main hosts are attacked (EFSA PLH, 2014). Because A. citrina is a polyphagous pest, experts recommended to evaluate this pest on all 'Citrus', 'Fortunella', 'Poncirus' and their hybrids for the fruit and the ornamental sectors.
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):
France (2001); France/Corse (2005); Greece (2007); Italy (2002)
Conclusion:
candidate
Justification (if necessary):
This pest is a candidate for the RNQP status according to the IIA2AWG. A. citrina has been reported in Italy, France and Greece, but its current distribution in EU is not precisely known because of possible confusion with A. aurantii. Southern areas of the EU are climatically suitable for the pest to establish and spread although expected impacts are likely to be minor since IPM programmes targeted at A. aurantii are considered to be effective in controlling A. citrina.
HOST PLANT N°1: Citrus (1CIDG) for the Ornamental 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?
No
Conclusion:
Evaluation continues
Justification (if necessary):
The interest in Citrus and related genera as ornamental plants has increased in recent years, and many varieties and hybrids are suitable for this purpose.
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:
This host grown as an ornamental is not thought to react differently to fruiting types, so the fruit SEWG information is applicable, as given:
As for other diaspidids, the first instar can be dispersed naturally by wind and by animals. After selecting a feeding site, the scale becomes sessile and no further dispersal occurs. Then spread can occur only with human assistance. Plants for planting are a possible pathway for introduction and spread of the pest (EFSA PLH, 2014).
As for other diaspidids, the first instar can be dispersed naturally by wind and by animals. After selecting a feeding site, the scale becomes sessile and no further dispersal occurs. Then spread can occur only with human assistance. Plants for planting are a possible pathway for introduction and spread of the pest (EFSA PLH, 2014).
5 - Economic impact:
Are there documented reports of any economic impact on the host?
Yes
Justification:
This host grown as an ornamental is not thought to react differently to fruiting types, so the fruit SEWG information is applicable, as given:
High densities of yellow scale cause cosmetic harm to the fruit and directly damage leaves, resulting in twig dieback. The scales were found to damage citrus fruit in some citrus-growing regions of California. It was an important pest of citrus in the San Joaquin Valley in the 1950s. There was no report of the pest for the last 18 years, maybe due to the introduction of insect growth regulators. A. citrina is no longer considered to be a significant pest of Californian Citrus. The pest was first recorded in Europe in 1994 for Italy, in 2001 for France and in 2007 for Greece, but without any significant damage reported.
High densities of yellow scale cause cosmetic harm to the fruit and directly damage leaves, resulting in twig dieback. The scales were found to damage citrus fruit in some citrus-growing regions of California. It was an important pest of citrus in the San Joaquin Valley in the 1950s. There was no report of the pest for the last 18 years, maybe due to the introduction of insect growth regulators. A. citrina is no longer considered to be a significant pest of Californian Citrus. The pest was first recorded in Europe in 1994 for Italy, in 2001 for France and in 2007 for Greece, but without any significant damage reported.
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:
Experts commented that yellow scales (without any distinction between A. aurantii and A. citrina) have significative impacts in a limited number of nurseries in IT. However treatments applied against A. aurantii, the presence of natural enemies in the Citrus orchards, and competition with A. aurantii, are considered to be sufficient to keep the population under control without other specific control measures.
CONCLUSION ON THE STATUS:
Disqualified: treatments applied against A. aurantii, the presence of natural enemies in the citrus orchards, and competition with A. aurantii, are considered to be sufficient to keep the population under control without specific control measures. Impact is therefore considered as 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:
- EFSA Panel on Plant Health (PLH) (2014) Scientific Opinion on the pest categorisation of Aonidiella citrina. EFSA Journal 2014;12(12):3929, 23 pp.doi:10.2903/j.efsa.2014.3929 http://www.efsa.europa.eu/en/efsajournal/doc/3929.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 Aonidiella citrina (Coquillet);