| Legend |
|---|
| Justification for qualification based on EPPO PM 4 Standards |
| Justification for disqualification |
| Additional or non-conclusive information |
| Standard text |
NAME OF THE ORGANISM: Comstockaspis perniciosa {Quadraspidiotus perniciosus} (QUADPE)
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?:
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
If necessary, please list the species:
-
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):
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); Bulgaria (2011); Croatia (2016); Czech Republic (2011); France (2011); Germany (2011); Greece (2008); Hungary (2013); Italy (2011); Italy/Sardegna (2011); Portugal (2011); Portugal/Azores (2011); Portugal/Madeira (2011); Romania (2011); Slovakia (2011); Slovenia (2013); Spain (2016); Spain/Islas Canárias (2011)
Conclusion:
Justification (if necessary):
Data of the presence of this pest on the EU territory are available in EPPO Global Database (https://gd.eppo.int/).
HOST PLANT N°1: Pyrus communis (PYUCO) for the Fruits (including hops) sector.
Origin of the listing:
New proposal
Plants for planting:
Plants intended for planting
3 - Is the pest already listed in a PM4 standard on the concerned host plant?
Yes
Conclusion:
Evaluation continues
Justification (if necessary):
Inspection for ' Quadraspidiotus perniciosus' recommended in EPPO Standard PM 4-27 Pathogen-tested material of Malus, Pyrus and Cydonia. However, in the responses to the questionnaire NL did not support regulation. FR commented for other hosts that the 'pest was totally endemic in orchards'. A full assessment is performed.
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:
Comstockaspis perniciosa, San Jose scale, is a polyphagous species (see García Morales et al., 2016). The host plant range could probably be much wider, but on some of the recorded host plants this insect cannot finish development, which means that these plant species are not true host plants. The importance of the host plant is different in different parts of the world, so for each region only the local literature sources can give a true picture. In general, this species is a serious pest on deciduous fruit trees including apple, pear, peach, plum, currants and some woody ornamental plants (Konstantinova, 1976; Davidson & Miller, 1990; Kozar, 1990; Kosztarab, 1996; cited in CABI, 2021). Different varieties of fruit species show different susceptibility in different parts of the world (Bichina & Gatina, 1976; Shalamberidze, 1978; Verma & Sriravasta, 1990; cited in CABI, 2021). The scale insect can be a serious pest in pear (Pyrus sp.; Jian, 1996; UC IPM, 2017).
Comstockaspis perniciosa has 1-5 generations in different parts of the world. Its development differs in these regions and detailed information can be found only in local publications. It overwinters in colder countries as first-instar larvae (crawler). In central Europe, the adults appear at the end of April, and in northern Europe 1 or 2 months later. The crawlers continue to appear for 1-2 months: the females have about 100 crawlers (Kosztarab and Kozar, 1988). The first-instar larva is the dispersal phase. It can be distributed by wind, birds or flying insects (Mague & Reissig, 1983; CAB 2021).
The most important means of transport into a new area, however, is infested nursery material. By this means the pest was accidentally introduced throughout the world (CABI, 2021)
[In responses to the questionnaire, FR commented that 'the pest was totally endemic in production orchards'.]
The Fruit SEWG considered that the pest was already widespread in orchards in the EU and that consequently plants for planting should not be considered as a significant pathway compared to natural dispersal of the first instar larva.
Comstockaspis perniciosa has 1-5 generations in different parts of the world. Its development differs in these regions and detailed information can be found only in local publications. It overwinters in colder countries as first-instar larvae (crawler). In central Europe, the adults appear at the end of April, and in northern Europe 1 or 2 months later. The crawlers continue to appear for 1-2 months: the females have about 100 crawlers (Kosztarab and Kozar, 1988). The first-instar larva is the dispersal phase. It can be distributed by wind, birds or flying insects (Mague & Reissig, 1983; CAB 2021).
The most important means of transport into a new area, however, is infested nursery material. By this means the pest was accidentally introduced throughout the world (CABI, 2021)
[In responses to the questionnaire, FR commented that 'the pest was totally endemic in production orchards'.]
The Fruit SEWG considered that the pest was already widespread in orchards in the EU and that consequently plants for planting should not be considered as a significant pathway compared to natural dispersal of the first instar larva.
5 - Economic impact:
Are there documented reports of any economic impact on the host?
Yes
Justification:
San Jose scales cause injury by feeding on twigs, branches, and fruit. They may also inject a salivary toxin while feeding. Infested fruit and wood develop a reddish purple ring (halo) surrounding each spot where a scale settles. Fruit infested by San Jose scale is often bumpy; in extreme cases, pears may be severely misshapen and stunted. Presence of either the insect or red ring on fruit causes it to be culled from fresh-market shipments. Pears may also be rejected for cannery use because insect feeding often causes sunken areas that cannot be removed by peeling. Heavy population can cause gumming and kill twigs, branches, and entire tree if left uncontrolled. Young trees may be killed before fruiting (UC IPM, 2017).
In Oregon orchard: An infestation level of 1% infested spurs of pear in late April or 4% in July will result in harvest (late September) damage in excess of 2% infested fruit. This last value approximates the tolerable economic loss for San Jose scale on pears (Westigard & Calvin, 1977).
The fruit SEWG highlighted that these were extreme cases.
In Oregon orchard: An infestation level of 1% infested spurs of pear in late April or 4% in July will result in harvest (late September) damage in excess of 2% infested fruit. This last value approximates the tolerable economic loss for San Jose scale on pears (Westigard & Calvin, 1977).
The fruit SEWG highlighted that these were extreme cases.
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?
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:
Justification:
The Fruit SEWG considered that the pest is managed by non-targeted controls (e.g. use of mineral oils) as used in classical approaches of orchards integrated pest management (see Golan et al., 2023). Plants in a nursery are regularly checked and a substantially free from requirement for all quality pests is considered enough.
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?
Yes
Conclusion:
Justification:
Monitoring program.
Use of insecticides.
Biocontrol.
Use of insecticides.
Biocontrol.
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 is not considered as a significant pathway compared to natural dispersal.
8 - Tolerance level:
Is there a need to change the Tolerance level:
No (new regulation proposal)
Proposed Tolerance levels:
No listing.
9 - Risk management measures:
Is there a need to change the Risk management measure:
No
Proposed Risk management measure:
No listing.
REFERENCES:
- Bichina TI & Gatina Esh (1976) Varietal susceptibility of apple trees to San Jose scale and its integrated control. Ustoichivost' Vinograda i Plodov. Kul'tur k Zabolevaniyam i Vreditelyam, 124-137. Stiinca, Kishinev: Moldavian SSR.
- CABI (2021) Diaspidiotus perniciosus (San José scale). CABI Digital Library (Accessed 31/Jul/2024). https://www.cabidigitallibrary.org/doi/10.1079/cabicompendium.46224.
- Davidson JA & Miller DR (1990) Ornamental plants. In Armoured Scale Insects, their Biology, Natural Enemies and Control, Vol. 4B (ed. Rosen D). Amsterdam, Netherlands: Elsevier, 603-632.
- García Morales M, Denno BD, Miller DR, Miller GL, Ben-Dov Y, Hardy NB. 2016. ScaleNet: A literature-based model of scale insect biology and systematics. Database. The Journal of Biological Databases and Curation, 2016: bav118. https://doi.org/10.1093/database/bav118. https://scalenet.info/catalogue/.
- Golan K, Kot I, Kmiec K & Gorska-Drabik (2023) Review. Approaches to Integrated Pest Management in Orchards: Comstockaspis perniciosa (Comstock) Case Study. Agriculture 13, 131.
- Jian H (1996) New record of fruit tree pest of Fujian - San Jose scale Quadraspidiotus perniciosus (Comstock) and its parasitoids. Journal of Fujian Agricultural University (China), 25(3).
- Konstantinova GM (1976). Coccids - pests of apple. Zashchita Rastenii 12:49-50.
- Kosztarab M (1996). Scale Insects of North Eastern North America: identification, biology, and distribution. Martinsville, USA: Virginia Museum of Natural History, 650 pp..
- Kosztarab M & Kozár F (1988) Scale insects of Central Europe. Dordrecht, Netherlands: Kluwer Academic Publishers. 455 pp.
- Kozár F (1990). Deciduous fruit trees. In Armored Scale Insects their Biology, Natural Enemies and Control. Vol. 4B (ed. Rosen D). Amsterdam, Netherlands: Elsevier Science Publishers B.V., 593-602.
- Mague DL & Reissig WH (1983) Airborne dispersal of San Jose scale, Quadraspidiotus perniciosus (Comstock) (Homoptera: Diaspididae), crawlers infesting apple. Environmental Entomology 12, 692-696.
- Shalamberidze NSh (1978). The resistance of plum cultivars to San Jose scale. Sadovodstvo, Vinogradarstvo i Vinodelie Moldavii, 4:41.
- Verma RR & Srivastava PM (1990) Response of different varieties of apple (Malus pumila) to pest infestation. Indian Journal of Agricultural Sciences 60(5), 338-339.
- Westigard PH & Calvin LD. 1977. Sampling San José in a Pest Management Program on Pear in Southern Oregon. Journal of Economic Entomology 70: 138–140
- UC IPM (2017) San Jose scale. In Pest management guidelines for agriculture – Pear. University of California, Agriculture and Natural Resources, publication 3455, pages 66-67