RMD -18-02: Pest Risk Management Document – Deregulation of Cydia 
latiferreana  (filbert worm)  
 
 
 
(Original )  
 
Preface  
 
As described by the International Plant Protection Convention (IPPC), Pest Risk Analysis (PRA) 
includes three stages: initiation, pest risk assessment and pest risk management. Initiating the 
PRA process involves identifying pests and pathways of concern a nd defining the PRA area. Pest 
risk assessment provides the scientific basis for the overall management of risk. Pest risk 
management is the process of identifying and evaluating potential mitigation measures which 
may be applied to reduce the identified p est risk to acceptable levels and selecting appropriate 
measures.  
   
This Risk Management Document (RMD) includes a summary of the findings of a pest risk 
assessment and records the pest risk management process for the identified issue. It is 
consistent w ith the principles, terminology and guidelines provided in the IPPC standards for 
pest risk analysis which may be found at the International Plant Protection Convention websit e.  
 
Table of Contents  
Executive Summary  ................................ ................................ ................................ .........................  2 
1.0 Purpose  ................................ ................................ ................................ ................................ ..... 2 
2.0 Scope  ................................ ................................ ................................ ................................ .........  2 
3.0 Definitions, abbreviations and acronyms  ................................ ................................ .................  2 
4.0 Background  ................................ ................................ ................................ ...............................  2 
5.0 Pest Risk Assessment Summary  ................................ ................................ ................................  3 
5.1 Distribution  ................................ ................................ ................................ ............................  3 
5.2 Pathways  ................................ ................................ ................................ ................................  3 
5.3 Potential Economic and Environmental Consequences  ................................ ........................  3 
5.4 Lifecycle  ................................ ................................ ................................ ................................ . 4 
6.0 Risk Managem ent Considerations  ................................ ................................ ............................  4 
6.1 Standards of the International Plant Protection Convention  ................................ ...............  4 
6.2 Eradication  ................................ ................................ ................................ .............................  4 
6.3 Potential Economic and Environmental Consequences  ................................ ........................  5 
6.4 International Trade  ................................ ................................ ................................ ................  5 
7.0 Ri sk Management Decision  ................................ ................................ ................................ .......  5 Page 2 of 6 
 
 8.0 References  ................................ ................................ ................................ ................................  6 
 
Executive Summary  
 
Cydia latiferrea na is an insect that is native to North America . Prior to 1995, phytosanitary 
import requirements and domestic movement requirements for Corylus  spp. nuts, seeds  and 
nursery stock  were in place to mitigate the risk of introducing this pest to uninfested areas of 
British Columbia . In 1995, this pest  was included in Schedule II of the Plant Protection 
Regulations  to modernize requirements.  
 
Cydia latiferrea na was reported for the first time in British Columbia in 1952 (Silver and Ross 
undated) and is now considered to be established in the province (Silver and Ross undated, 
Clements et al . 2011,  Otvos et al . 2012 ). Cydia  latiferrea na can no longer be considered  a 
regulated pest in Canada  due to its widespread distribution . The CFIA will take the necessary 
steps to deregulate this pest, including removing it from Schedule II of the Plant Protection 
Regulations  and from the List of Pest s Regulated by Canada.  
 
1.0 Purpose  
 
The purpose of this document is to record risk management considerations and to inform 
stakeholders of the CFIA’s decision to deregulat e Cydia  latiferrea na (Walsingham) . 
 
2.0 Scope  
 
This RMD  includes a summary of the findings of the pest risk assessment and records the 
Canadian Food Inspection Agency’s (CFIA ’s) decision to deregulate  C. latiferreana . 
 
Information pertaining to current import requirements for specific plants or plant products may 
be obtained from the Automated Import Reference System ( www.inspection.gc.ca/airs ).  
 
3.0 Definitions, abbreviations and acronyms  
 
Definitions of terms used in this document can be found in the International Standard for 
Phytosanitary Measures 5: Glossary of phytosanitary terms  or the Plant Health Glossary  of 
Terms . 
 
4.0 Background  
 
Cydia latiferreana  is native to North America and is found in association with many wild and 
cultivated nuts, but is particularly common in acorns ( Quercus  spp.) and hazelnuts ( Corylus  spp.)  
(Wiman and Bell 2017) . 
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 This insect is a common pest of hazelnut production in  the states of Oregon and Washington . A 
2016 survey of the Fraser Valley  conducted by  British Columbia’s Ministry of Agriculture, Plant 
Health Unit, confirmed  it is also present  in British Columbia,  but at a level below the Economic 
Injury L evel, thus no treatment is required ( BCAGRI  2016) . Most of the commercial hazelnut 
production in Canada is in the province of British Columbia. The majority of this acreage is in 
the Fraser Valley, althoug h there are some small o rchards  on Vancouver Island and in the  
Interior of British Columbia .  
 
Cydia latiferreana  has been considered a quarantine pest o f Canada for many years. It was 
included in the List of Pests Regulated by Canada  and in Schedule II of the Plant Protection 
Regulations  (SOR/95 -212) in 1995. The objective of these regulations was to mitigate the risk of 
introducing this insect to uninfested areas of British Columbia. These regulations restrict the 
importation and domestic movement of hazelnuts and Corylus spp.  nursery stock into British 
Columbia. The phytosanitary restrictions on Corylus spp. nursery stock have made it difficult for 
producers to obtain new cultivars, replant orchards  and expand hazelnut production in British 
Columbia.  
 
5.0 Pest Risk Assessment Summary  
 
The phytosanitary risk presented by C. latiferreana  has been assessed by the  CFIA on two 
occasions. The first assessment was completed in 1996 (PRA 1996 -15), and  was reviewed and 
updated in 2017 ( PRA 2017 -71).  
 
5.1 Distribution  
 
Filbertworm is native to North America and is now considered to be widespread in Canada, the 
United States and northern Mexico (CFIA 1996; Gilligan and Epstein 2014) . Human -assisted 
movement of infested host material is the main pathway for this insect to spread  over  longer 
distances.  The insect spreads locally by adult flight  (CFIA  1996) . 
 
Hazelnut orchards in British Columbia’s  Fraser Valley have not seen significant damage from 
this pest in the past, though C. latiferreana  has been detected in this area and is known to be 
present in other parts of the province  (BCAGRI 2016) . In p articular, it is a known pest of  Quercus 
garryana  (Garry oak) on Vancouver Island and the Gulf Islands  (Otvos et al . 2012 ). 
 
5.2 Pathways  
 
Host plants include: Castanea  spp. (chestnut), Corylus  spp. (hazelnut), Fagus  spp. (beech), 
Juglans  spp. (walnut), Prunus  spp. (stone fruit), Punica  spp. (pomegranate) and Quercus  spp. 
(oak).  Fruits, nuts, used containers , and fruit - and nut -bearing plants , are potential pathways for 
human assisted spread (CFIA  1996).  
 
5.3 Potential Economic and Environmental Consequences  
 Page 4 of 6 
 
 Cydia latiferreana  is a key pest in hazelnut orchards in  Oregon and Washington (Wiman and Bell 
2017 ). Dama ge is caused by  larvae tunneling into the nuts to feed. Damaged nuts may drop 
early, in advance of ripening , although larvae may also be present in mature nuts at harvest . If 
left untreated, damage can range from 12% to 37%; however , with the use of appropriate pest 
mana gement practi ces, damage can be reduced (AliNiazee 1983).  Cydia  latiferreana  does not 
affect the vitality of the host tree  (Wiman and Bell 2017) . Cydia  latiferreana  has also been 
reported to infest acorns and is considered to be an impediment to the preservation and 
recovery of the Garry oak ecosystem in the Pacific Northwest region  (Otvos et al . 2012) .  
 
Economic and environmental consequences of deregulating C. lat iferreana  are expected  to be 
minimal , as the insect is already wide ly distributed in Canada.   
 
5.4 Lifecycle  
 
Cydia latiferreana  generally has one generation  per year and is  capable of  overwinter ing as 
diapausing  larvae in silk cocoons. Adults emerge from the middle of June until the end of 
October. Emergence is synchronized with the formation and development of the filbert nut. 
Mating takes place soon after emergence and eggs are laid singly, generally on leaves close to 
nuts. The eggs hatch in 8 -10 days and the larvae tunnel through the husk and into the nut 
where they feed. Larvae mature in 3 -4 weeks, leave the nut and form a cocoon where they 
spend the winter on the ground or in cracks and crevices on trees. So me larvae may overwinter 
2-5 cm beneath the soil surface  (CFIA  1996) .  
 
6.0 Risk Management Considerations  
 
6.1 Standards of the International Plant Protection Convention  
 
In order to meet international standards and be considered a quarantine pest, an organism 
must be a pest of potential economic importance that is not yet present or is present, but not 
widely distributed, and being officially controlled  (IPPC 2017) . Cydia  latiferreana no longer 
qualifies as a quarantine pest in Canada because it is widespread . Although CFIA regulates this 
pest ’s pathways into British Columbia, this pest is not under official control in the province.  
In addition, c ontinued enforcement of im port and domestic movement requirements to 
prevent further introduction  and spread of C. latiferreana  in Canada is no longer technically 
justified considering that the pest is already widesprea d.  
 
6.2 Eradication  
 
Eradication of C. latiferreana  in British Columbia is not a viable option because it has been 
found in association with w ild host plants (e.g., hazelnut and  Garry oak), landscape trees and 
commercial hazelnut orchards. Therefore, eradication would be impractical and costly, with a 
low probability of success.  
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 6.3 Potential Economic  and Environmental  Consequences  
 
Cydia latiferreana  can be successfully managed in hazelnut orchards using pest surveillance in 
combination with cultural and chemical control measures. Pheromone traps may be used to 
determine when adults are present and to ensure insecticides are applied at the appropriate 
times . Gathering  and destroying prematurely fallen nuts which may contain insect larvae, and 
cleaning packing sheds and reusable containers may also help to  reduce population levels.  
 
Because this insect is already present in the main hazelnut production areas of British Columbia  
and is not subject to official control , deregulation is expected to have a minimal impact on the 
spread of C. latiferreana  within t he province.  
 
Cydia latiferreana  is native to North America and is already present on wild host trees in 
Canada. In British Columbia, it is a known pest of Garry oak acorns, Quercus garryana , on 
Vancouver Island, and the Gulf Islands. Consequently, deregulation is not expected to have a 
significant impact on the environment.  
 
6.4 International Trade  
 
Cydia latiferreana  is native and widespread in the U.S. and northern  Mexico  and has not been 
identified as a pest of quarantine concern by any countr y outside  of North America. Neither 
USDA -APHIS nor any of the U.S. state plant health agencies ha ve regulations in place targeting 
this pest. Deregulation of this pest i s not expected to have an impact on export trade with the 
U.S. or Mexico.  
 
7.0 Risk Management Decision  
 
The CFIA will proceed with deregulation of C. latiferreana . This decision is based on the fact that 
C. latiferreana  is native to North America, widespread in Canada  and not subject to official 
control  within the province of British Columbia . Erad ication of this insect would be impractical 
and costly with  a low probability of success. Effective methods for managing this pest at the 
producer level are available.  Cydia  latiferreana  no longer meets the International Plant 
Protection Convention definition of a quarantine pest and continued enforcement of impo rt 
and domestic requirements is  no longer technically justified.    
 
The CFIA intends to remove  C. latiferreana  from Schedule II of the Plant Protection Regulations .  
 
Until this regulatory change is made, the following changes will serve to functionally deregulate 
C. latiferreana . The CFIA will revoke  the phytosanitary import  requirements for Corylus  spp. 
nuts , as described in directive D -95-08: Phytosanitary import requirements for fresh temperate 
fruits and tree nuts . In addition, the CFIA will not enforce item 14 (10) of Schedule II of the Plant 
Protection Regulations  as it pertains to the domestic movement of fi lbert ( Corylus  spp.).  
 Page 6 of 6 
 
 As part of the deregulation  process , C. latiferrena will be removed from the L ist of Pests 
Regulated by Canada and the Automated Import Reference System (AIRS) will be updated to 
reflect that the importation of articles of Corylus  spp. are  no longer subject to the requirement s 
described in directive D -95-08. Trading partners will be notified through the World Trade 
Organization that C. latiferrena is no longer a pest regulated by Canada.  
 
8.0 References  
 
AliN iazee, M.  T. 1983.  Pest status of filbert (hazelnut) insects: a 10 -year study. The Canadian  
Entomol ogist. 115:1155 -1162.  
BCAGRI  (British Columbia Ministry of Agriculture). 2016. Filbertworm, Cydia  (Melissopus )  
latiferreana , survey in British Columbia hazelnut orchards, 2016.  
CFIA ( Canadian Food Inspection Agency ). 1996. Cydia latiferreana, The filbertworm – PRA  
1996 -15. Plant Health Risk Assessment Unit. Canadian Food Inspection Agency. Ottawa, 
Ontario.  
Clements, D. R., Luginbill, S., Jordan, D. A., van Dragt, R.  and Pelant, R. K. 2011.  Techniques to 
promote Garry oak seedling growth and survival in areas with high levels of herbivory 
and competition. Northwest Science, 85(2): 172 -181.  
Gilligan, T. M.  and Epstein, M.  E. 2014.  Tort ricids of Agricultural Importance: Cydi a latiferreana   
[online]. http://idtools.org/id/leps/tortai/Cydia_latiferreana.htm  (accessed 14 
November 2018 ). 
IPPC. 2017.  International Standard for Phytosanitary Measures, ISPM No. 5, Glossary  
of phytosanitary terms, Food and Agricultural Organization of the United Nation, Rome, 
Italy.  
Otvos, I. S., Mills, D. A. and Conder, N. 2012.  Within -crown distribution, attack, and  
germination of Curculio occidentis -damaged and Cydia latiferreana -damaged Garry oak 
acorns in Victoria, British Columbia, Canada. The Canadian Entomologist, 144: 419 -434.  
Silver, G. T. and Ross, D. A. undated . Province of British Columbia, Forest Insect Survey, p. 115 -
127.  Source, http://www.cfs.nrcan.gc.ca/pubwarehouse/pdfs/33449.pdf   Accessed, 
November 23, 2018.  
Wiman, N. and Bell, N. 2017 . Hazelnut Pests. In: Hollingsworth, C.S., editor. Pacific Northwest  
Insect Management Handbook [online]. Corvallis, OR: Oregon State University. 
https://pnwhandbooks.org/insect/nut/hazelnut  (accessed 31 January 2018).