| Legend |
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| Justification for qualification based on EPPO PM 4 Standards |
| Justification for disqualification |
| Additional or non-conclusive information |
| Standard text |
NAME OF THE ORGANISM: Cacopsylla (1CCPSG)
GENERAL INFORMATION ON THE PEST
Name as submitted in the project specification (if different):
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?:
No
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?
- No: Fruits (including hops) sector
If necessary, please list the species:
Cacopsylla species feeding on Pyrus in the west Paleartic are C. bidens, C. fera, C. notata, C.permixta, C. pyri, C. pyricola, C. pyrisuga (Burckhardt and Hodkinson, 1986). Economically relevant species in Europe on pear are C. bidens, C. pyri, C. pyricola and C. pyrisuga
There are few data on Cacopsylla species on Cydonia: C. mali (Ellis, 2001-2024) and C. melanoneura (Ossianilsson 1992).
Species with economic relevance in apple are C. melanoneura (Förster, 1948), C. mali (Schmidberger, 1836) and C. picta (Förster 1848). Additionally, 13 other Cacopsylla species have been found on apples (in Italy, Fischnaller et al. 2017). Regarding the reported developmental hosts of these insect species, however, it rather seems that these psyllids are only occasionally present on apple.
There are few data on Cacopsylla species on Cydonia: C. mali (Ellis, 2001-2024) and C. melanoneura (Ossianilsson 1992).
Species with economic relevance in apple are C. melanoneura (Förster, 1948), C. mali (Schmidberger, 1836) and C. picta (Förster 1848). Additionally, 13 other Cacopsylla species have been found on apples (in Italy, Fischnaller et al. 2017). Regarding the reported developmental hosts of these insect species, however, it rather seems that these psyllids are only occasionally present on apple.
Is it justified that the pest is listed at a taxonomic rank below species level?
Not relevant
Conclusion:
- Candidate: Fruits (including hops) sector
Justification (if necessary):
Species of Cacopsylla differ substantially from one another in biology. Some species are economically important, others not. Evaluation continues at species level.
In the responses to the questionnaire, AT, DE, ES, FR, NL and SI considered that Cacopsylla was a pest of concern. AT supported listing at genus since species identification was not providing any extra value for control; whereas most of the responding countries (DE, ES, FR and NL) supported listing at species level (host specificity, morphological differentiation is possible). SI supported deregulation in the EU (see pathway). Assessment will continue providing information (when possible) at species level.
In the responses to the questionnaire, AT, DE, ES, FR, NL and SI considered that Cacopsylla was a pest of concern. AT supported listing at genus since species identification was not providing any extra value for control; whereas most of the responding countries (DE, ES, FR and NL) supported listing at species level (host specificity, morphological differentiation is possible). SI supported deregulation in the EU (see pathway). Assessment will continue providing information (when possible) at species level.
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):
-
Conclusion:
Candidate
Justification (if necessary):
For Pyrus (Ossianilsson, 1992; Burckhard and Hodkinson 1986; Etropolska et al. 2015): Pear sucker species are widespread relevant pests in European pear orchards (Civolani et al. 2023 for review)
- C. bidens: Bulgaria, France, Grece, Italy.
- C. pyri: Austria, Bulgaria, Czech Republic, Denmark, France, Greece, Hungary, Italy, Malta, The Netherlands, Portugal, Slovenia, Slovakia, Spain, Sweden, Switzerland, Turkey.
- C. pyricola: Austria, Belgium, Bulgaria, Czech Republic, Croatia, France, Germany, Great Britain, Greece, Hungary, Italy, Malta, The Netherlands, Poland, Portugal, Romania, Slovenia, Slovakia, Spain, Sweden, Switzerland, Turkey.
- C. pyrisuga: Austria, Bulgaria, Czech Republic, France, Germany, Great Britain, Greece, Slovakia, Switzerland, Italy, Georgia, Denmark, Sweden, Norway
For Cydonia (De Jong et al., 2015, Ellis, 2001-2024, Ossianilsson, 1992): The mentioned Cacopsylla species are widespread in Europe, however data for Cydonia as a (reproductive) host are rare.
- C. mali (Schmidberger, 1836): On Malus, occasionally found on Cydonia and Pyrus. It is reported in Austria, Belgium, Bulgaria, Czech Republic, Denmark, Finland, France, Germany, Italy, Ireland, Netherlands, Poland, Romania, Slovakia, Slovenia, Sweden Austria, Denmark, Italy, Sweden,
- C. melanoneura (Förster 1948): On Rosaceae, occasionally on Cydonia. Austria (Riedle-Bauer, personal observation), Czech Republic, Denmark, Finland, Germany (Jarausch B., personal communication), Italy, Norway, Poland, Slovenia, Sweden, Spain, Türkiye.
For Malus (De Jong et al. 2015, Ellis, 2001-2024, Ossianilsson, 1992): C. picta, C. melanoneura and C. mali are regularly occuring in wide parts of Europe.
- C. mali (Schmidberger, 1836) on Malus, occasionally found on Cydonia and Pyrus. It is reported in Austria, Belgium, Bulgaria, Czech Republic, Denmark, Finland, France, Germany, Italy, Ireland, Netherlands, Poland, Romania, Slovakia, Slovenia, Sweden Austria, Denmark, Italy, Sweden.
- C. melanoneura (Förster 1948): On Rosaceae, mainly Crataegus but regularly on Malus. It is present in Austria (Riedle-Bauer, personal observation), Czech Republic, Denmark, Finland, Germany (Jarausch B., personal communication), Italy, Norway, Poland, Slovenia, Sweden, Spain, Türkiye.
- C. picta (Förster 1848): On Malus, present in Austria, Belgium, Czech Republic, Finland, France, Germany, Italy, Poland, Slovakia, Slovenia, Sweden, Spain
- C. bidens: Bulgaria, France, Grece, Italy.
- C. pyri: Austria, Bulgaria, Czech Republic, Denmark, France, Greece, Hungary, Italy, Malta, The Netherlands, Portugal, Slovenia, Slovakia, Spain, Sweden, Switzerland, Turkey.
- C. pyricola: Austria, Belgium, Bulgaria, Czech Republic, Croatia, France, Germany, Great Britain, Greece, Hungary, Italy, Malta, The Netherlands, Poland, Portugal, Romania, Slovenia, Slovakia, Spain, Sweden, Switzerland, Turkey.
- C. pyrisuga: Austria, Bulgaria, Czech Republic, France, Germany, Great Britain, Greece, Slovakia, Switzerland, Italy, Georgia, Denmark, Sweden, Norway
For Cydonia (De Jong et al., 2015, Ellis, 2001-2024, Ossianilsson, 1992): The mentioned Cacopsylla species are widespread in Europe, however data for Cydonia as a (reproductive) host are rare.
- C. mali (Schmidberger, 1836): On Malus, occasionally found on Cydonia and Pyrus. It is reported in Austria, Belgium, Bulgaria, Czech Republic, Denmark, Finland, France, Germany, Italy, Ireland, Netherlands, Poland, Romania, Slovakia, Slovenia, Sweden Austria, Denmark, Italy, Sweden,
- C. melanoneura (Förster 1948): On Rosaceae, occasionally on Cydonia. Austria (Riedle-Bauer, personal observation), Czech Republic, Denmark, Finland, Germany (Jarausch B., personal communication), Italy, Norway, Poland, Slovenia, Sweden, Spain, Türkiye.
For Malus (De Jong et al. 2015, Ellis, 2001-2024, Ossianilsson, 1992): C. picta, C. melanoneura and C. mali are regularly occuring in wide parts of Europe.
- C. mali (Schmidberger, 1836) on Malus, occasionally found on Cydonia and Pyrus. It is reported in Austria, Belgium, Bulgaria, Czech Republic, Denmark, Finland, France, Germany, Italy, Ireland, Netherlands, Poland, Romania, Slovakia, Slovenia, Sweden Austria, Denmark, Italy, Sweden.
- C. melanoneura (Förster 1948): On Rosaceae, mainly Crataegus but regularly on Malus. It is present in Austria (Riedle-Bauer, personal observation), Czech Republic, Denmark, Finland, Germany (Jarausch B., personal communication), Italy, Norway, Poland, Slovenia, Sweden, Spain, Türkiye.
- C. picta (Förster 1848): On Malus, present in Austria, Belgium, Czech Republic, Finland, France, Germany, Italy, Poland, Slovakia, Slovenia, Sweden, Spain
HOST PLANT N°1: Malus (1MABG) for the Fruits (including hops) sector.
Origin of the listing:
Commission Implementing Directive (EU) 2014/98/EU (previous version)
Plants for planting:
Plants intended for planting
3 - Is the pest already listed in a PM4 standard on the concerned host plant?
No
Conclusion:
Evaluation continues
4 - Are the listed plants for planting the main* pathway for the "pest/host/intended use" combination? (*: significant compared to others):
No
Conclusion:
Not candidate
Justification:
C. melanoneura and C. picta have a migratory life cycle. They estivate and overwinter on conifers. In early spring, the overwintered adults migrate to pome fruits on a regional scale. The adults of C. picta reproduce exclusively on apple and migrate soon after emergence (emigrants) to conifers in mountainous regions, and return to apple plants in early spring (remigrants). C. melanoneura also uses conifers as overwintering host plants but prefers to reproduce on hawthorn (Crataegus), despite its ability to reproduce on apple (Mayer et al., 2010). Populations of C. melanoneura from hawthorn and apple can differ (Malagnini et al., 2013) and were influenced by their previous experience (Mayer et al., 2011). Plants for planting are not the major pathway for insect distribution, although it is likely possible that single specimen are transported with plants for planting.
C. mali lives on apples all year round and also reproduces there (Ossianilsson 1992). It seems possible that specimen are transported with propagation material as the species overwinters in the egg stage on Malus (Ossianilsson 1992). There are no conclusive data to which extent adults have a migratory behavior and therefore naturally spread from apple orchard to apple orchard. It cannot be excluded that plants for planting substantially contribute to pest spread.
However, the Fruit SEWG considered that for all these species, plants for planting should not be considered as a significant pathway.
The impact of psyllids in apple is mainly linked to their ability to vector ‘Candidatus Phytoplasma mali’, causing apple proliferation disease (see section on impact). While Cacopsylla picta is a vector in different regions, the vector efficiency of C. melanoneura varies between different populations. This species is considered the main vector in Northwestern Italy but plays a minor role / no role in Northeastern Italy and other European regions (Frisinghelli et al, 2000; Tedeschi & Alma, 2007; Jarausch et al. 2011; Mayer et al., 2011; Corretto et al., 2023). High phytoplasma titers were measured in overwintered adults already at their first appearance in the orchards after remigration from their overwintering hosts. Data indicate transmission of the disease on a regional scale by remigrant adults of C. picta and at a local scale within the same season by emigrant adults which developed on infected plants (Jarausch et al., 2011). In addition, C. picta can vertically transmit the ‘Candidatus Phytoplasma mali’ to its progeny (Mittelberger et al., 2017).
In addition factors like the phytoplasma subtype and genetic features of the phyllids influenced e.g. the acquisition time (Corretto et al., 2023). The phytoplasma could be detected in all the life stages of e.g. C. melanoneura; the phytoplasma load significantly increased during the period spent on conifers. In many cases also nymphs and newly emerged adults contained a sufficient quantity of phytoplasma to consider these stages infective (Candian et al., 2020).
[Remark: In the responses to the questionnaire, SI commented that Cacopsylla spp. are not mainly transmitted by plants for planting.]
C. mali lives on apples all year round and also reproduces there (Ossianilsson 1992). It seems possible that specimen are transported with propagation material as the species overwinters in the egg stage on Malus (Ossianilsson 1992). There are no conclusive data to which extent adults have a migratory behavior and therefore naturally spread from apple orchard to apple orchard. It cannot be excluded that plants for planting substantially contribute to pest spread.
However, the Fruit SEWG considered that for all these species, plants for planting should not be considered as a significant pathway.
The impact of psyllids in apple is mainly linked to their ability to vector ‘Candidatus Phytoplasma mali’, causing apple proliferation disease (see section on impact). While Cacopsylla picta is a vector in different regions, the vector efficiency of C. melanoneura varies between different populations. This species is considered the main vector in Northwestern Italy but plays a minor role / no role in Northeastern Italy and other European regions (Frisinghelli et al, 2000; Tedeschi & Alma, 2007; Jarausch et al. 2011; Mayer et al., 2011; Corretto et al., 2023). High phytoplasma titers were measured in overwintered adults already at their first appearance in the orchards after remigration from their overwintering hosts. Data indicate transmission of the disease on a regional scale by remigrant adults of C. picta and at a local scale within the same season by emigrant adults which developed on infected plants (Jarausch et al., 2011). In addition, C. picta can vertically transmit the ‘Candidatus Phytoplasma mali’ to its progeny (Mittelberger et al., 2017).
In addition factors like the phytoplasma subtype and genetic features of the phyllids influenced e.g. the acquisition time (Corretto et al., 2023). The phytoplasma could be detected in all the life stages of e.g. C. melanoneura; the phytoplasma load significantly increased during the period spent on conifers. In many cases also nymphs and newly emerged adults contained a sufficient quantity of phytoplasma to consider these stages infective (Candian et al., 2020).
[Remark: In the responses to the questionnaire, SI commented that Cacopsylla spp. are not mainly transmitted by plants for planting.]
5 - Economic impact:
Are there documented reports of any economic impact on the host?
Yes
Justification:
The impact of the psyllids is mainly linked to their ability to vector ‘Ca. Phytoplasma mali’ i.e. C. picta and C. melanoneura. Overwintered adults retained high quantities of phytoplasmas, representing the most worrisome stage. Also in several nymphs and newly emerged adults a sufficient quantity of phytoplasmas was detected to consider these stages infective. So both remigrating adults as well as newly emerged adults represent a risk for the spread of the disease (Jarausch et al., 2011; Jarausch et al. 2019; Candian et al., 2020).
Apple proliferation phytoplasma affects almost all apple cultivars. It may reduce fruit size by about 50%, weight by 63-70%, and the fruit quality, as well as it may reduce tree vigour and increase susceptibility to powdery mildew (Podosphaera leucotricha) (EPPO 2024). Fruit number is usually not affected, but the fruit color is unsatisfactory and the taste is poor, with the result that as much as 80% of the fruits are unmarketable. The root system may be poorly developed in young trees. When the percentage of diseased trees is high and the production decreases too much, orchards have to be uprooted, often several years within their normal life span (Seemüller et al. 2011). Yield reduction caused by apple proliferation disease in Italy has led to an economic loss of about 100 million Euros in 2001 (Strauss, 2009).
C. mali and C. picta occasionally directly damage plants due to their feeding activity. They suck sap off leafstalks, peduncles, leaves, and flower buds and thereby causing loss of flowers, distortion of young shoots and leaves and excessive honeydew. In most cases, damage is minor (pflanzenkrankheiten.ch).
[Remark: In the responses to the questionnaire, AT questioned whether direct damage was acceptable. DE expressed reservations to list them as vectors of RNQPs.]
Apple proliferation phytoplasma affects almost all apple cultivars. It may reduce fruit size by about 50%, weight by 63-70%, and the fruit quality, as well as it may reduce tree vigour and increase susceptibility to powdery mildew (Podosphaera leucotricha) (EPPO 2024). Fruit number is usually not affected, but the fruit color is unsatisfactory and the taste is poor, with the result that as much as 80% of the fruits are unmarketable. The root system may be poorly developed in young trees. When the percentage of diseased trees is high and the production decreases too much, orchards have to be uprooted, often several years within their normal life span (Seemüller et al. 2011). Yield reduction caused by apple proliferation disease in Italy has led to an economic loss of about 100 million Euros in 2001 (Strauss, 2009).
C. mali and C. picta occasionally directly damage plants due to their feeding activity. They suck sap off leafstalks, peduncles, leaves, and flower buds and thereby causing loss of flowers, distortion of young shoots and leaves and excessive honeydew. In most cases, damage is minor (pflanzenkrankheiten.ch).
[Remark: In the responses to the questionnaire, AT questioned whether direct damage was acceptable. DE expressed reservations to list them as vectors of RNQPs.]
What is the likely economic impact of the pest irrespective of its infestation source in the absence of phytosanitary measures? (= official measures)
Major
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?
No
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?
Conclusion:
Justification:
Impact is rated as 'major' for Apple proliferation, 'minor' for C. mali itself.
6 - Are there feasible and effective measures available to prevent the presence of the pest on the plants for planting at an incidence above a certain threshold (including zero) to avoid an unacceptable economic impact as regards the relevant host plants?
No
Conclusion:
Justification:
C. melanoneura and C. picta estivate and overwinter on conifers and remigrate to apple orchards over several weeks in spring (Jarausch et al. 2019, for review). Studies on the closely related plum sucker C. pruni (Paleskic et al. 2017) indicate that insecticide application over six to eight weeks at early developmental stages of the trees i) imply several treatments with knock down insecticides (environmental effects?) and ii) will rather not fully prevent the presence and feeding of remigrating Cacopsylla individuals on apple plants.
C. mali presence on plant for planting can be controlled by insecticides.
C. mali presence on plant for planting can be controlled by insecticides.
7- Is the quality of the data sufficient to recommend the pest to be listed as a RNQP?
Conclusion:
Justification:
CONCLUSION ON THE STATUS:
Disqualified: plants for planting are not considered to be a significant pathway and feasible and effective measures available to prevent the presence of the pest on the plants for planting are lacking.
8 - Tolerance level:
Is there a need to change the Tolerance level:
No (listed in a previous version of Commission Implementing Directive (EU) 2014/98/EU)
Proposed Tolerance levels:
9 - Risk management measures:
Is there a need to change the Risk management measure:
No
Proposed Risk management measure:
REFERENCES:
- AGES (2024) Evaluation of factors determining distribution, impact, detection and characterization of fruit tree phytoplasmoses (APOPHYT). https://dafne.at/content/report_release/fa851e7f-3a03-4c13-9b1e-259195adbb16_1.pdf
- Candian V, Monti M & Tedeschi R (2020) Temporal dynamics of 'Ca. Phytoplasma mali' load in the insect vector Cacopsylla melanoneura. Insects 11(9), 592. doi: 10.3390/insects11090592.
- Čermák V & Lauterer P (2008) Overwintering of psyllids in South Moravia (Czech Republic) with respect to the vectors of the apple proliferation cluster phytoplasmas. Bulletin of Insectology 61 (1): 147-148.
- Corretto E, Trenti Mm Štarhová Serbina L, Howie JM, Dittmer J, Kerschbamer C, Candian V, Tedeschi R, Janik K & Schuler H (2023) Multiple factors driving the acquisition efficiency of apple proliferation phytoplasma in Cacopsylla melanoneura. Journal of Pest Science https://doi.org/10.1007/s10340-023-01699-1
- Frisinghelli C, Delaiti L, Grando MS, Forti D & Vindimian ME (2000): Cacopsylla costalis (Flor 1861), as a vector of apple proliferation in Trentino. Journal of Phytopathology 148, 425–431
- Jarausch B, Schwind N, Fuchs A & Jarausch W (2011) Characteristics of the spread of apple proliferation by its vector Cacopsylla picta. Phytopathology 101, 1471-1480.
- Jarausch B, Tedeschi R, Sauvion N, Gross J, Jarausch W (2019) Psyllid vectors. In: Bertaccini A, Weintraub PG, Rao GP, Mori N (eds) Phytoplasmas: Plant Pathogenic Bacteria - II: Transmission and Management of Phytoplasma - Associated Diseases, Springer Singapore, pp 53–78
- Malagnini V, Pedrazzoli F, Papetti C, Cainelli C, Zasso R, Gualandri V, Pozzebon A & Ioriatti C (2013) Ecological and genetic differences between Cacopsylla melanoneura (Hemiptera, Psyllidae) populations reveal species host plant preference. PLoS ONE 8(7): e69663. doi:10.1371/journal.pone.0069663
- Mayer CJ, Vilcinskas A & Gross J (2010) Chemically mediated multitrophic interactions in a plant–insect vector-phytoplasma system compared with a partially nonvector species. Agricultural and Forest Entomology 13(1), 25-35.
- Seemüller E, Carraro L, Jarausch W & Schneider B (2011) Apple proliferation phytoplasma. In: Virus and Virus-like Diseases of Pome and Stone Fruits (eds Hadidi A, Barba M, Candresse T & Jelkmann W). The American Phytopathological Society, 67-73.
- Ossiannilsson F (1992) The Psylloidea (Homoptera) of Fennoscandia and Denmark. Fauna Entomol Scand. Vol. 26. Brill E. J., Leiden.
- Paleskić C, Bachinger K, Brader G, Kickenweiz M, Engel C, Wurm L, Czipin L & Riedle-Bauer M (2017) Cage and field experiments as basis for the development of control strategies against Cacopsylla pruni, the vector of European Stone Fruit Yellows. Ann Appl Biol 170:357–368. https://doi.org/10.1111/aab.12340
- Pflanzenkrankheiten.ch (2024) Apfelblattsauger. https://www.pflanzenkrankheiten.ch/krankheiten-an-kulturpflanzen-2/kern-steinobst/krankheiten-apfel/cacopsylla-mali-apfel#:~:text=Der%20Apfelblattsauger%20(Cacopsylla%20mali)%20%C3%BCberwintert,die%20Insekten%20ausgewachsen%20und%20gefl%C3%BCgelt.
- Strauss E (2009) Microbiology. Phytoplasma research begins to bloom. Science 325, 388-390.
- Tedeschi R & Alma A (2007) ‘Candidatus Phytoplasma mali’: the current situation of insect vectors in northwestern Italy. Bulletin of Insectology 60(2), 187-188