RMD – 22 – 02: Pest risk management proposal for the  regulation of Cydalima 
perspectalis in Canada 
 
Effective date: TBD 
 
Preface 
 
As described by the International Plant Protection Convention (IPPC), Pest Risk Analysis (PRA) include s 
three stages: initiation, pest risk assessment and pest risk management. Initiating the PRA process 
involves identifying pests and pathways of concern and defining the PRA area. Pest risk assessment 
provides the scientific basis for the overall manag ement of risk. Pest risk management is the process of 
identifying, evaluating and selecting potential mit igation measures which may be applied to reduce the  
identified pest risk to acceptable levels. 
 
This Risk Management Document (RMD) includes a summ ary of the findings of a pest risk assessment and 
records the pest risk management process for the id entified issue. It is consistent with the principle s, 
terminology and guidelines provided in the IPPC sta ndards for pest risk analysis available at 
the International Plant Protection Convention website . 
 
Table of Contents  
 
Executive summary ................................. ................................................... ............................................. 2 
Purpose ........................................... ................................................... ................................................... .. 3 
Scope ............................................. ................................................... ................................................... ... 3 
Definitions, abbreviations and acronyms ........... ................................................... ................................... 3 
Background ........................................ ................................................... .................................................. 3 
Pest risk assessment summary ...................... ................................................... ....................................... 6 
Pest biology ...................................... ................................................... ................................................ 6 
Host Plants for C. perspectalis  .................................................. ................................................... ......... 7 
Pathways for entry, establishment and spread ...... ................................................... ........................... 8 
Potential economic consequences ................... ................................................... ................................. 9 
Pest management.................................... ................................................... ......................................... 9 
Risk management considerations .................... ................................................... ................................... 10 
Standards of the International Plant Protection Con vention ........................................... ................... 10 
Risk management considerations .................... ................................................... ............................... 11  
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 Risk management proposals ......................... ................................................... ...................................... 11 
Risk Management Option 1 - Status quo: No specific phytosanitary measures for C. perspectalis  ....... 11 
Risk Management Option 2 – Federal regulation of th e pest –Creation of a localized regulated area in 
the Greater Toronto Area (GTA) and Niagara peninsul a (municipalities with positive detections from 
2021) ............................................. ................................................... ................................................. 1 2 
Risk Management Option 3 – Federal regulation of th e pest –Creation of a regulated area for all of 
Ontario (recommended) ............................. ................................................... .................................... 14 
Recommended Option ................................ ................................................... ....................................... 16 
References ........................................ ................................................... ................................................. 1 7 
 
Executive summary 
 
Cydalima perspectalis,  box tree moth (BTM) , is native to East Asia and has become a serious in vasive pest 
of Buxus  spp. plants in Europe, where it continues to sprea d. C. perspectalis  caterpillars feed on the leaves 
of boxwood ( Buxus spp.) plants, which can lead to plant defoliation i f left unmanaged. The feeding damage 
from the larvae is easily visible on the tree, with  leaves often appearing skeletonized. The defoliati on and 
dieback are unsightly, and reduce the plant value. Boxwood plants can be infested with all life stages  of 
C. perspectalis .  
 
Despite the rapid spread of C. perspectalis  in Europe and non-native parts of Asia, it has not  become 
widespread in the Americas. In 2018, three box tree  moths were reported in Ontario, Canada, and the 
identity of the pest was confirmed by the Canadian Food Inspection Agency (CFIA) in November 2018 
(iNaturalist, 2018; CFIA, 2018). The detection of C. perspectalis  prompted the establishment of a BTM 
Technical Advisory Committee (TAC) to help guide co llaborative response actions with key partners 
including monitoring, outreach and education and re search. The industry associations, Landscape Ontari o 
(LO) and the Canadian Nursery Landscape Association  (CNLA), with support from the City of Toronto, 
University of Guelph and University of Toronto asse mbled a large BTM field scouting and treatment 
program in partnership with the Ontario Ministry of  Agriculture, Food, and Rural Affairs (OMAFRA) and 
the CFIA. Collaborative ground surveys and pheromon e trapping were carried out in 2019, 2020, and 2021 . 
In 2021, surveillance was expanded to include the P rovinces of Nova Scotia, Québec, Ontario (outside t he 
known infested area) and British Columbia.  To date , C. perspectalis  has only been found to be active in 
Ontario in: Greater Toronto Area, Cookstown, George town, Milton, Mississauga, Burlington, Hamilton, 
Waterloo, Grimsby, Vineland, St. Catharines, Niagar a-on-the-Lake and North Pelham. New York State 
(USA) also reported detections of C. perspectalis  in 2021. Although boxwood plants are not native to  North 
America, they are widely distributed in North Ameri can nurseries, gardens, and parks as an important 
ornamental shrub and thus, the establishment and sp read of C. perspectalis  in North America is a concern 
to the landscape and nursery industries. In 2019, a nnual market value of boxwood in production in Cana da 
was approximately $40 million CDN.  
 
In Canada,  C. perspectalis is not currently a regulated pest. In the U.S., C. perspectalis  is listed in the U.S. 
Department of Agriculture-Animal and Plant Health I nspection Service (USDA-APHIS) Regulated Plant Pest 
List  (USDA-APHIS 2020b). Following the first detection of this moth in Toronto in 2018, the USDA-APHIS  
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 implemented Federal Order DA-2020-07 in March 2020 revising the phytosanitary requirements for  Buxus 
spp.,  Euonymus spp., and  Ilex spp. plants for planting imported from Canada to pr event the introduction 
of Cydalima perspectalis into the U.S. Shipments from Canada were required t o be accompanied by a 
phytosanitary certificate and an additional declara tion stating that the shipment has been officially 
inspected and found to be free of C. perspectalis or produced in a facility or area officially recogn ized by 
the CFIA as free of C. perspectalis . On May 26, 2021, following the detection of BTM in a nursery facility 
in St. Catharines, Ontario and the subsequent inter ception of the pest in the U.S., USDA-APHIS publish ed 
Federal Order DA-2021-11 prohibiting the importatio n of plants for planting of Buxus spp.,  Euonymus spp., 
and  Ilex spp. from Canada to prevent the introduction of thi s pest into the U.S. via the plants for planting 
pathway. 
 
Given the economic impacts of C. perspectalis  to the Canadian nursery sector, the Canadian Nurse ry 
Landscape Association (CNLA) has submitted a writte n request to the CFIA to consider federal regulatio n 
of the pest.  As a result, this Risk Management Doc ument (RMD) seeks to obtain input from all 
stakeholders regarding three options for managing t he pest risk posed by C. perspectalis.   
Purpose 
 
The purpose of this document is to consult with int ernal and external stakeholders on risk management 
options for regulating Cydalima perspectalis,  box tree moth (BTM) in Canada. 
Scope 
 
This risk management document includes a summary of  CFIA’s risk assessments on C. perspectalis  and 
presents three pest risk management options for the  pest in Canada under the authority of the Plant 
Protection Act .  
 
Information pertaining to import requirements for s pecific plants or plant products may be obtained fr om 
the Automated Import Reference System . 
Definitions, abbreviations and acronyms 
 
Definitions of terms used in this document can be f ound in the International Standard for Phytosanitary 
Measures 5: Glossary of phytosanitary terms  or the Plant Health Glossary of Terms . 
Background 
 
Native to Japan, Korea, and China, box tree moth (B TM), Cydalima perspectalis (Walker), is an invasive 
pest causing severe damage to boxwood, Buxus  spp., in Europe (Maruyama and Shinkaji 1987; Nacam bo 
et al.  2014; Park 2008; Wan et al.  2014; Wang 1980). C. perspectalis  was first detected in Europe in 2007, 
where it was first observed in Germany (Billen, 200 7) and the Netherlands (van der Straten and Muus, 
2009). Establishment likely occurred after multiple  accidental introductions via shipments of ornament al 
box trees from Asia (van der Straten and Muus, 2009 ). In the short time frame since its establishment,  C.  
4 
 perspectalis  has continued to spread into new areas and is now found in up to 30 European countries 
(Bella 2013; Nacambo et al. , 2014; CABI 2020; Strachinis et al.  2015). This spread has been aided by the 
free movement of live plants in the European Union and the presence of the two native species of 
boxwood ( B. Sempervirens and B. Balearica ) in the natural environment in Europe (Brua 2013; Le uthardt 
et al.  2010; Matošević 2013). 
 
Cydalima perspectalis has a narrow host range, preferring boxwood ( Buxus spp.). Boxwoods are planted 
as ornamentals and typically used for edging, as he dges, and/or clipped into different shapes to make 
topiaries. When infested, the plants are disfigured  by the loss of leaves, webbing spun by the larvae,  as 
well as larval excrement. Larvae feed mostly on lea ves but may also attack the bark. Boxwood plants ar e 
not native to Canada and there are no natural stand s, thus making it less significant as a potential 
environmental threat in Canada.  However, Buxus  spp. are widely distributed in North American nurs eries, 
gardens, and parks as an important ornamental shrub  and prior to 2021, it was a common nursery plant 
exported to the U.S. Based on a survey conducted in  2019 by Canadian Nursery Landscape Association 
(CNLA), annual value of boxwood in production (plan ts sold in one year and plants in the field) was $4 0M, 
with annual sales by Canadian growers estimated at $15M annually.  
 
In October 2018, the CFIA was notified of a communi ty scientist report of a detection of C. perspectalis  in 
an urban Toronto neighbourhood and in November 2018 , the CFIA confirmed its presence in the area 
(iNaturalist, 2018; CFIA, 2018). This was the first  confirmed report of this pest in North America. In  April 
2021, the CFIA confirmed the first detection of C. perspectalis  at a nursery facility in St. Catharines, 
Ontario, and the collaborative monitoring program w as expanded within Ontario and monitoring was 
initiated in British Columbia, Quebec, and Nova Sco tia. Subsequently, C. perspectalis  was detected at 
facilities in the United States that received Buxus  spp. plants from the Canadian facility. In May 202 1, the 
USDA-APHIS published Federal Order DA-2021-11 to pr ohibit the importation of plants of Buxus spp.,  
Euonymus spp., and  Ilex spp from Canada (USDA-APHIS 2021).   
 
Euonymus spp. and Ilex spp. were reportedly included in the USDA-APHIS fed eral order as suspect C. 
perspectalis  hosts, although no detections of this pest have be en reported on these taxa in Canada. To 
date, C. perspectalis  has only been detected in Canada on Buxus  spp. plants and only in southwestern 
Ontario. Detections in Ontario in 2021 have been co nfirmed in: Greater Toronto Area, Cookstown, 
Georgetown, Milton, Mississauga, Burlington, Hamilt on, Waterloo, Grimsby, Vineland, St. Catharines, 
Niagara-on-the-Lake and North Pelham (Figures 1 and  2).  During the 2022 survey season more detections  
are expected and there has been a confirmed detecti on in Tecumseh, Ontario in June 2022. To encourage 
early detection, the CFIA and its partners have an active social media campaign to engage residents in  
high-risk areas. When C. perspectalis  is confirmed in an area, educational information i s distributed, and 
homeowners are encouraged to treat the pest or remo ve Buxus  spp. and replace them with a non-host 
shrub. 
 
  
5 
  
Figure 1. 2021 box tree moth survey results for Ont ario. 
 
 
Figure 2. 2021 box tree moth survey results for Can ada (BC, ON, QC, NS) 
 
6 
 Currently, C. perspectalis  is not on Canada’s list of federally regulated pes ts.  In October 2021, the 
Canadian Nursery Landscape Association (CNLA) submi tted a letter to the CFIA requesting the regulation  
of C. perspectalis  for all three genera of hosts for which export res trictions are currently in place: Buxus  
spp., Euonymus  spp. and Ilex  spp.  
This Risk Management Document (RMD) summarizes pest  risk assessments and presents three options 
for regulating C. perspectalis  in Canada: 
(1)  no federal regulation 
(2)  establishment of a localized regulated area in the Greater Toronto Area (GTA) and Niagara 
peninsula (municipalities with positive detections) , or 
(3)  establishment of the province of Ontario as a regul ated area. 
Pest risk assessment summary 
 
Pest biology  
 
Geographical location, larval food source, as well as temperature have significant impacts on the biol ogy 
of Cydalima perspectalis with respect to adult longevity and fecundity, larv al developmental time, 
diapause, number of generations in a year, etc.  
 
Eggs are laid on the underside of host leaves, usua lly in a cluster of about 10 to 20 eggs (Kenis et al.  2013; 
Salisbury et al.  2012). The eggs hatch in about three days and youn g larvae feed on the underside of the 
leaves. The larvae produce webbing on the leaves wh ich helps to shield them from predators. Larvae tak e 
about two weeks to mature and pupate. Pupae take ab out two weeks to transform from caterpillar into 
moth (Strachinis et al.  2012; van der Straten and Muus 2009).  
 
Depending on a number of biological factors such as  temperature and humidity, C. perspectalis  can have 
several generations per year (Maruyama and Shinkaji , 1987). In 2021, in Ontario, two generations of ad ult 
moths (peaking around the last week of June/first w eek of July and again around the last week of 
August/first week of September) were observed, in c ontrast to the three to fivegenerations reported in  
Europe. In Canada, larvae of the first generation w ere observed from April to early June, with the fir st 
pupa observed in late May. Adult activity began dur ing the second week of June. The second generation 
of larvae were observed from late June to mid-Augus t. Pupae were found from late July to mid-
September.  
 
Cydalima perspectalis  overwinters in the larval stage in a silken cocoon  spun between host leaves. Adult 
moths live for about two weeks and can fly up to 10  km per year (Brua 2013; Leuthardt et al.  2010; 
Matošević 2013). During the day, they can be found resting on host plants or on other surrounding plan ts. 
Larvae representing the overwintering population in  Ontario in 2021 were found actively feeding on Buxus  
spp. plants from late August to mid-October. Overwi ntering structures were observed beginning in July.  
 
Damage to boxwood plants is caused by the larvae fe eding on the leaves and sometimes on the bark. 
Boxwood trees can survive being attacked by box tre e moth provided that the larvae do not eat the bark  
of the main stems. Younger larvae feed by eating th e lower surfaces of the leaves, leaving the upper 
epidermis intact. Older larvae feed inside a pale w hite tent of webbing that they have spun for protec tion  
7 
 and skeletonize the leaves, leaving only the midrib s and outer margin intact. Signs of an infestation 
include: webbing, green pellet shaped frass, cast s kins, head capsules, and chewed leaves. Boxwood pla nts 
can be infested with all life stages of the C. perspectalis  (Nacambo et al. , 2014). Unlike the severe damage 
reported in Europe, most of the boxwood plants obse rved to be infested with C. perspectalis  in Canada 
sustained only minor to moderate damage in 2021. Ho wever, some unmanaged hedges were reported to 
be completely defoliated by C. perspectalis  feeding occurring over approximately two years. 
 
Given that the pest has only been reported in Ontar io since 2018, there is still limited information o n the 
behaviour and possible impacts of C. perspectalis  in North America. Trapping and scouting activities  
continue to provide data on the phenology and biolo gy of C. perspectalis  in Ontario.  
 
Host Plants for C. perspectalis  
 
Cydalima perspectalis is primarily a pest of Buxus plant species (Family Buxaceae)  (van der Straten and 
Muus 2009). In Europe, Buxus spp. recorded as hosts of this moth are: 
• Buxus balearica  (Balearic boxwood) 
• Buxus bodinieri  
• Buxus harlandii  (Harland boxwood) 
• Buxus megistophylla  
• Buxus microphylla (Little-leaf box) 
• Buxus rugulosa  
• Buxus sempervirens (Common boxwood) 
• Buxus sinica  (Chinese box) 
 
One species of boxwood, Buxus vahlii , is native to Puerto Rico and the U.S. Virgin Isla nds (van Kretschmar 
2017). Currently, Canadian nurseries propagate thei r boxwood from on-farm stock as a recommended 
best practice for the prevention of Cylindrocladium buxicola (boxwood blight). Some Canadian nurseries 
will purchase finished boxwood plants from US suppl iers for re-sale if stock is in short supply domest ically. 
Boxwoods were originally brought to North America a s nursery stock from Europe and Asia, bred, and 
sold to homeowners. Thus, they are primarily found in urban areas, where they are planted around house s 
and in small gardens. There are no natural stands o f boxwood in Canada unlike the situation in Europe 
(CFIA 2011). 
 
In Asia, C. perspectalis is also a pest of Buxus spp., although some authors note plant species othe r than 
Buxus as hosts in Asia (Wang 2008, Korycinska and Eyre 20 11): Euonymus alata (Winged spindle) and E. 
Japonicus (Japanese spindle tree, family Celastraceae ), Ilex purpurea (Purple-leaved holly, family 
Aquifoliaceae ), Murraya paniculata  (Orange jasmine, family Rutaceae ). 
 
Euonymus alatus  is a deciduous shrub in the Celastraceae  family. The leaves of this species turn bright red  
or reddish purple in the fall and are shed from the  bush, revealing the corky branches. This makes the  
plant unsuitable and unattractive to hibernating C. perspectalis  larvae. Brua (2013) reported that 
Euonymus  plants are not suitable hosts for C. perspectalis .  In this study, C. perspectalis  was reported to 
cause significant damage to the leaves of six Buxus  spp., however there was no damage to the leaves of  
E. europaeus  and E. japonicus  and just an insignificant amount of damage to the leaves of E. alatus . (Details 
on how these results were obtained were not provide d.). In addition, Matošević et al.  (2017) reported 
that field-collected C. perspectalis  larvae starved to death (100% mortality) when prov ided with E. 
japonicus  leaves. Similarly, Wiesner et al.  (2021) also concluded that C. perspectalis  could not survive or  
8 
 successfully pupate while being fed with E. alatus  or E. fortunei  during larval development in laboratory 
studies.  In Europe, C. perspectalis  has only been recorded from Buxus  species (Bury et al  2017, Kenis et 
al 2013, Wan et al  2014). Van der Straaten and Muus (2009) also cite unpublished tests performed by the 
Plant Protection Service of the Netherlands that sh owed that European populations do not attack 
anything but Buxus . Based on the surveillance and control activities in Ontario, C. perspectalis  has only 
been detected on Buxus spp. plants and not on Euonymus  spp. or Ilex  spp. When scouting C. perspectalis  
populations, field technicians would check nearby p lants for C. perspectalis  larvae or feeding damage 
(Euonymus  spp., Pachysandra terminalis , Ilex  spp.) but no signs of damage or C. perspectalis  life stages 
have been found on these species to date. Given the  above observations, it is reasonable to conclude t hat 
Euonymus  spp. and Ilex  spp. are not suitable hosts for C. perspectalis  in Europe or in Canada. 
 
Pathways for entry, establishment and spread 
 
Introduction of C. perspectalis into Europe is believed to be via infested Buxus plants imported from East 
Asia (Kenis et al.  2013; Salisbury et al.  2012). Natural dispersal of adult moths might have  been the primary 
method by which this moth arrived in the southern c oast of England from continental Europe (Korycinska  
and Eyre 2011), from Germany to Switzerland (van de r Straten and Muus 2009), and from Turkey to 
Greece (Strachinis et al.  2011). Data from Germany indicate that natural dis persal is about 5-10 km (van 
der Straten and Muus 2009). Eggs, laid on the under side of host leaves, and young larvae, with their 
greenish colour, can travel undetected on host plan ts (Kenis et al.  2013; Salisbury et al.  2012). Eggs, larvae, 
and pupae could survive long distance transport or storage on boxwoods (Plant et al.  2019, van 
Kretschmar 2017). There are two native species of b oxwood, B. sempervirens and B. balearica that are 
found in the natural European environment. The shru bby nature of boxwood, especially in the nursery 
stage, provides deep pockets that make it easy for eggs and larvae to be well hidden inside the plant such 
that it takes effort to find them if present. In th is state, they can survive and travel easily on pla nts, without 
being detected (Salisbury et al.  2012, Kenis et al.  2013).  
 
There are currently no specific import requirements  for boxwood coming into Canada. In general, 
consignments of plants for planting must be free of  regulated pests and of soil and may also be subjec t to 
additional requirements depending on the species an d country or region of origin. A phytosanitary 
certificate is required for all plants for planting  imports, which includes inspection by the exportin g 
country, and may be subject to inspection at the ti me of entry into Canada. Importation from areas oth er 
than the continental U.S. must be free from soil. C urrently, Canadian nurseries propagate their boxwoo d 
from on-farm stock as a recommended best practice f or the prevention of Cylindrocladium buxicola  
(boxwood blight). Some Canadian nurseries will purc hase finished boxwood plants from US suppliers for 
re-sale if stock is in short supply domestically. B est Management Practices at Canadian nurseries, inc luding 
the adoption of a C. perspectalis  pest module (trapping, monitoring, treatments, etc .), greatly support 
efforts to mitigate risks at nurseries and represen t the best approach for limiting the spread of C. 
perspectalis  via the nursery pathway. 
 
In April 2021, C. perspectalis  was first detected in a nursery through the on-far m C. perspectalis  
surveillance pest module. Following the detection, the nursery immediately stopped all shipments of ho st 
plants, notified customers, industry and government  agencies, inspected and treated all host plants. 
Community science and surveillance was further expa nded in the region in the Greater Toronto Area to 
delimit pest infested area.  
  
9 
 Cydalima perspectalis  can survive in areas with Buxus  spp. hosts where the minimum winter temperature 
is about -30°C. It overwinters in the larval stage in a silken cocoon spun between host leaves. Temper ature 
threshold for the development of eggs, larvae, and pupae vary between 8°C and 12°C. Main Buxus species 
in trade in Canada are Buxus sempervirens and B. microphylla. Buxus sempervirens is grown for 
landscaping purposes in the most temperate regions of Canada such as the coast of British Columbia and  
southern Ontario (Brouillet et al.  2010+). Buxus microphylla is cultivated in Canada and nurseries in both 
British Columbia and Ontario offer this species for  sale (Brouillet et al.  2010+). Hybrid  Buxus cultivars are 
very popular in Canada. They are hardy in both sout hern Ontario and British Columbia (Drysdale 2008). 
CLIMEX modelling maps, using both past and future r ealistic climate normals, strongly indicate this mo th 
can and will survive in Canada. Specifically, In On tario, from Toronto southward. It may also infest a reas 
north of Toronto from Montreal to North Bay. Future  establishment in British Columbia and the Maritime s 
seems possible (CFIA 2019d). 
 
Potential economic consequences 
 
Boxwood plants are considered by the nursery indust ry to be among the top five most important woody 
ornamental plants in Canada, with the annual value of transactions estimated at approximately $40 
million, of which domestic sales amount to $15 mill ion.  
 
In June 2022, the CNLA reported a loss-to-date of s ales of over $6.5 million dollars to their growers since 
the publication of U.S. Federal Order DA-2021-11.  Most customers order boxwood as one of  multiple 
items in an order and as such, growers are losing, or at risk of losing, customers due to their inabil ity to 
supply all requested products. The CNLA has also re ported that there will be potential impacts to U.S.  
customers, who rely on Canadian growers as seedling  and transplant providers. 
 
Pest management 
 
Boxwoods infested by C. perspectalis can be treated with registered chemical insecticide s or biopesticides 
based on Bacillus thuringiensis (Bt) (Kenis et al.  2013). Bioinsecticides based on Bt serotype kursta ki (Btk) 
have been effective against C. perspectalis  larvae and is the recommended control method in Eu rope 
(Guérin, 2018; Göttig and Herz, 2016; Lefort et al. , 2014). In Ontario, Btk provides excellent control  of C. 
perspectalis  larvae and can be used to effectively manage this pest when peak larval feeding for each 
generation is accurately identified. Some defoliate d hedges were observed to recover after Btk treatme nt 
during each C. perspectalis  generation.  
 
Chelonus tabonus, Tyndarichus  spp. and Trichogramma spp. are reported to parasitize C. perspectalis eggs 
(Göttig and Herz, 2016; Wan et al. , 2014). Casinaria  spp., Compsilura concinnata , Dolichogenidea stantoni , 
Exorista  sp., Protapanteles mygdonia  and Pseudoperichaeta nigrolineata  are larval parasitoids of C. 
perspectalis (Belokobylskij and Gninenko, 2016; Shi and Hu, 2007 ; Wan et al. , 2014). In laboratory studies, 
entomopathogenic nematodes Steinernema carpocapsae  and Heterorhabditis bacteriophora  caused high 
mortality of C. perspectalis larvae. Brachymeria lasus  and Apechthis compunctator  are pupal parasitoids 
of C. perspectalis (Wan et al. , 2014). In 2021, scouting in Ontario led to observ ations of a parasitoid wasp 
(Ichneumonidae ) attacking C. perspectalis  pupae. A total of seven specimens were collected o ver the 
summer.  More research is warranted to assess wasps native t o North America as well as Asian parasitoids 
of C. perspectalis  to establish a viable biological control program i n Ontario. Chelonus tabonus  (Sonan), a  
10 
 larval braconid parasitoid, was identified as the m ost promising candidate for classical biological co ntrol 
due to its high parasitism in China. 
 
In Ontario, pheromone traps, ground scouting, and c ommunity science surveillance (outreach and 
assistance with trap placement and monitoring) have  been used to delineate the area of C. perspectalis  
infestation. Pheromone traps are an effective metho d of capturing adult male moths and are used to 
detect presence or absence of the pest in an area a s well as to indicate flight period(s). Ground scou ting 
is an effective means of detecting C. perspectalis . Removal and replacement of host plants from priva te 
properties was attempted when C. perspectalis  was first detected in Toronto, but it was difficul t to identify 
the location of all host plants and not all home ow ners were open to removal of host plants from their  
property. As this pest can fly, pest eradication by  targeted removal of host plants from a single prop erty 
was not feasible. The province of Ontario is workin g towards supporting long term management tools 
including insecticides and mating disruption. An in tegrated pest management approach is recommended 
for management of C. perspectalis  in Southern Ontario which includes ground scouting , trapping, well-
timed insecticide applications and a communication plan to engage and educate homeowners to help 
detect, report and manage this pest. 
Risk management considerations 
Standards of the International Plant Protection Con vention 
 
Canada does not currently regulate C. perspectalis . It is listed by U.S. Department of Agriculture-An imal 
and Plant Health Inspection Service (USDA-APHIS) on  its Regulated Plant Pest List  (USDA-APHIS 2020b). 
 
International Standard for Phytosanitary Measures 5  (ISPM 5) defines a regulated quarantine pest as a 
pest of potential economic importance to the area e ndangered thereby and not yet present there, or 
present but not widely distributed and being offici ally controlled (IPPC 2022). 
 
A quarantine pest must meet the definition of “a pe st of potential economic importance to the area 
endangered thereby and not yet present there, or pr esent but not widely distributed and being official ly 
controlled”. The guidelines for official control in clude, among other elements, that measures be 
mandatory and that domestic and import requirements  should have the same or equivalent effect. 
 
The CFIA conducted multiple assessments on various aspects of C. perspectalis including pest  
categorisation, biology, hosts, pathways and potent ial impact over the past 10 years (2011-061, 2018-
175, 2019-060, 2019-061, 2019-135, 2019-150, 2019-1 79, 2019-193, 2019-199, 2021-086, 2021-087, 
2021-091, 2021-096).  
 
Although the source of the detection of C. perspectalis  in Canada remains unknown, its presence is an 
indication that there is a viable pathway of entry.  The experience in Ontario has shown the ability of  the 
pest to establish and spread. However, the pathway for introduction of the pest in Ontario remains 
unknown as it was first reported in an urban neighb ourhood. There were no reports in the nursery 
sector until it spread naturally from the Toronto i nfestation. Natural dispersal is possible, but limi ted 
due to the lack of natural boxwood stands in Canada  that would contribute to population growth and 
spread. Human-mediated spread is the primary means by which this moth spreads from one place to 
another. Economic and environmental consequences ar e rated medium as this moth has the potential 
to have significant negative impact on the trade of  boxwood, especially with the United States.  
11 
  
Cydalima perspectalis satisfies the criteria of being present but not wid ely distributed and being of 
potential economic importance.    
 
Risk management considerations 
 
Although C. perspectalis  is not currently regulated in Canada, the Canadian  Nursery Landscape Association 
has worked closely with its members and provincial partner associations to educate on this pest, and p est 
modules have been drafted to mitigate the risk of m oving C. perspectalis  with nursery plants. Since 2020, 
the CFIA has been working closely with the industry  sector to develop a C. perspectalis  systems approach, 
based on the principles of pest free place of produ ction/site as per ISPM 10, to establish confidence and 
ensure the nursery pathway is not a pathway for spr ead. A pest-free place of production must have 
systems in place to: establish and maintain pest fr eedom, verify pest freedom, and maintain product 
identity and phytosanitary security of any shipment . In addition, Buxus  spp., Ilex  spp. and Euonymus  spp. 
from Ontario are not sold to British Columbia. Brit ish Columbia is a major producer of these species a nd 
sells them to buyers in other provinces but, becaus e of movement restrictions related to Lymantria dispar 
dispar  (spongy moth) and Popillia japonica  (Japanese beetle) in addition to the extended grow ing season 
and warmer climate in British Columbia, there is no  market for Ontario product west of the Rocky 
Mountains.  
 
Based on the surveillance and control activities in  Ontario, C. perspectalis  has only been detected on Buxus  
spp. plants. When scouting C. perspectalis  populations, field technicians would check nearby plants for C. 
perspectalis  larvae or feeding damage ( Euonymus  spp., Pachysandra terminalis , Ilex  spp) but no signs of 
damage or C. perspectalis  life stages have been found on these species to da te. These observations align 
with the findings of Wiesner et al. (2021), who con firmed C. perspectalis  could not survive or successfully 
pupate while being fed E. alatus  or E. fortunei  during larval development in laboratory studies. F ollowing 
the detection of C. perspectalis  in New York State, control activities within the s tate have so far only 
applied to Buxus  spp. plants from regulated counties to prevent the  spread of C. perspectalis  to other 
parts of the United States. The CFIA believes that the scientific data currently available does not su pport 
the development of phytosanitary measures for  Euonymus spp. and Ilex spp. as hosts of this pest. 
Risk management proposals 
 
The CFIA presents herein three pest risk management  options for C. perspectalis  in Canada. Stakeholders 
will have an opportunity to comment on the proposal  during the comment period stated below. Once 
feedback from stakeholders has been received, the C FIA will consider the comments and determine the 
most appropriate option. Once a risk management dec ision has been finalized, the CFIA will revise this  
document to include information about the decision and timelines for implementing phytosanitary 
measures. The finalized risk management decision do cument will be posted on the CFIA website . 
 
Risk Management Option 1 - Status quo: No specific phytosanitary measures 
for C. perspectalis  
  
12 
 Under this option, C. perspectalis  would not be designated as a regulated pest in Can ada.  The CFIA would 
continue to work with stakeholders, including provi nces and industry associations, to monitor the spre ad 
of the pest.  CFIA will continue to support communi ty science efforts, but will not conduct its own pe st 
surveys.  The CFIA will continue to advocate on the  behalf of Canadian growers with respect to the U.S . 
Federal Order, based on surveillance data from grow ers, public reports, and provincial stakeholders. P est 
modules for C. perspectalis  will continue to be recommended for any facility t hat produces Buxus  spp., 
Euonymus  spp., and Ilex  spp.  Establishment of Pest-Free Places of Product ion and Pest-Free Production 
Sites based on the principles of ISPM 10 will also be encouraged.  Industry has recently expressed a 
commitment to ensure that the nursery stock pathway  will not be a pathway for spread of the pest.  
Emerging populations, when detected, could be contr olled by host removal or treatment by industry 
and/or provincial stakeholders. 
 
Pros: 
• as Buxus  spp. are the only hosts of C. perspectalis and as Buxus  spp. are non-native to Canada, the 
economic and environmental impacts to Canada will b e limited to the nursery and landscape 
industry in Canada   
• natural spread of C. perspectalis  may be slowed by the absence of natural stands of boxwoods in 
Canada 
• industry would continue to be able to trade inter-p rovincially without restrictions or additional 
phytosanitary requirements   
• continue to rely on industry best practices 
Cons 
• the nursery industry may be limited to domestic sal es for an extended period of time 
• domestic sales of Buxus  spp. may decline as the risk of the pest increases , further impacting the 
$15 million domestic market 
• it is anticipated that exports of the three plant t axa will continue to be prohibited entry into the 
U.S. until USDA-APHIS de-regulates C. perspectalis, recognizes trapping data indicating that the 
pest is confined to Ontario or is satisfied that th e risks associated with the importation of the 
three taxa has been sufficiently mitigated and amen ds their current import requirements 
 
Risk Management Option 2 – Federal regulation of the  pest –Creation of a 
localized regulated area in the Greater Toronto Are a (GTA) and Niagara 
peninsula (municipalities with positive detections from 2021)  
 
Under this option, C. perspectalis  would be added to CFIA’s Regulated Pest List  and would become 
federally regulated pest.  This option would involv e: 
• the establishment of a regulated area in the Greate r Toronto Area (GTA) and the Niagara 
peninsula which would be considered infested with C. perspectalis  (see Figure 3) 
• regulatory controls applied to Buxus  spp. only (see Host Plants section above) 
• implementation of domestic movement controls for Buxus  spp. moving out of the regulated 
area. Specifically, facilities producing Buxus  spp. within the regulated area would be required t o 
implement a systems-approach to prevent pest spread  (e.g., pest module) if they want to move 
or sell Buxus  spp. outside the regulated area 
• movement of Buxus  plants out of the regulated area would require aut horization by an 
inspector, through an inspection and issuance of a Domestic Movement Certificate.   
13 
 Authorization would be dependent on the systems in place at the facility and may require visual 
inspection by CFIA inspectors 
• unrestricted movement of Buxus  spp. within the regulated area  
• surveillance focussing on production areas outside the regulated area  
• implementation of import restrictions including pro hibition of imports of Buxus  spp. from the 
infested area in New York State, U.S.A., into Briti sh Columbia.  Other prohibitions/restrictions 
may also be necessary 
Pros 
• provides control measures to slow the human assiste d spread of the pest throughout Ontario 
and the rest of Canada 
• alignment of pest regulatory status with the U.S.  
• responds to industry request for regulation to supp ort re-establishment of trade with the U.S  
 
Cons 
• requires a more labour-intensive systems approach f or preventing movement of potentially-
infested plants until treatment has been applied 
• CFIA will be required to enforce domestic movement requirements and resources will be 
redirected from other priority activities 
• this option is the most resource intensive for the CFIA and potentially also for industry 
• expansion of the regulated area may be required soo n after publication based on the results of 
the 2022 survey  
14 
  
Figure 3. Option 2 – Proposed Regulated Area in the  Greater Toronto Area and Niagara peninsula 
(note the actual regulated area may vary) 
 
Risk Management Option 3 – Federal regulation of the  pest –Creation of a 
regulated area for all of Ontario (recommended) 
 
Under this option, C. perspectalis  would be added to CFIA’s Regulated Pest List  .  This option includes: 
• establishing a regulated area encompassing the enti re province of Ontario  (see Figure 4). 
• regulatory controls applied only to Buxus  spp. (see Host Plants section above) 
• implementation of domestic movement controls for Buxus  spp. moving out of the regulated 
area. Specifically, facilities producing Buxus  spp. within the regulated area would be required t o 
implement a system to prevent pest spread (e.g., pe st module) if they want to move or sell 
Buxus  spp. outside the regulated area.  Facilities furth er from main area of infestation may 
qualify to establish Pest-Free Places of Production  and Pest-Free Production Sites in accordance 
with ISPM 10 
• movement of Buxus spp. plants out of the regulated area would require  authorization by an 
inspector, through an inspection and issuance of a Domestic Movement Certificate  
 
15 
 Authorization would be dependent on the systems in place at the facility and may require visual 
inspection by CFIA inspectors 
• unrestricted movement of Buxus  spp within the regulated area 
• surveillance focussing on production areas outside the regulated area  
• implementation of import restrictions including pro hibition of imports of Buxus  spp. from the 
infested area in New York State, U.S.A., into Briti sh Columbia.  Other prohibitions/restrictions 
may also be necessary 
Pros 
• no domestic movement restrictions within Ontario 
• provides control measures to slow the human-assiste d spread of the pest out of Ontario to the 
rest of Canada 
• alignment of pest regulatory status with the U.S.  
• responds to industry request for regulation to supp ort re-establishment of trade with the U.S. 
Cons 
• requires a more labour-intensive systems approach f or preventing movement of potentially-
infested plants until treatment has been applied bu t number of impacted plants will be reduced 
as all sales within Ontario will be in the regulate d area 
• CFIA will be required to enforce domestic movement requirements and resources will be 
redirected from other priority activities 
 
 
 
16 
  
Figure 4. Option 3 – Proposed regulated area for al l of Ontario 
 
Recommended Option 
Based on the discussions with the Canadian BTM Tech nical Advisory Committee , the CFIA recommends 
proceeding with Option 3  - Federal regulation of the pest –Creation of a re gulated area for all of 
Ontario , in order to slow the spread of BTM and protect no n-infested areas in Canada. 
 
   
17 
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