Risk Management Proposal:  
Amendments to the import health standards  
152.02: Importation and Clearance of Fresh Fruit 
and Vegetables into New Zealand , and  
Commodity Sub -class: Fresh Fruit/Vegetables  
Lychee, ( Litchi chinensis ) from Taiwan  
 
 
Vapour heat treatment followed by  cold treatment  to manage Bactrocera dorsalis  and 
Zeugodacus  cucurbitae  on fresh lychee  from Taiwan  
 
 
Prepared for  public consultation   
by Horticulture Imports Team  
Animal and Plant Health Directorate  
 
 
 
January 2023Disclaimer  
While every effort has been made to ensure the information in this publication is accurate, 
the Ministry  for Primary Industries does not accept any responsibility or liability for error of 
fact, omission, interpr etation or opinion that may be present, nor for the consequences of any 
decisions based on this information.  
This publication is also available on the Ministry for Primary Industries  website at  
http://www.mpi.govt.nz/news -and-resources/publications/   
 
© Crown Copyright – Ministry  for Primary Industries   
i Contents  Page 
Submissions  1 
1 General information  3 
1.1 Purpose  3 
1.2 Background  3 
1.3 Timing and consultation  3 
1.4 Background and context to consultation  4 
2 Biosecurity risk associated with fresh lychees from Taiwan  4 
3 Proposed changes to the requirements for fresh lychees from Taiwan  6 
4 Rationale for the proposed amendment to the lychee standards  6 
5 Feasibility of the proposed cha nge to the standard  7 
6 References  8 
Appendix 1: Vapour heat treatment  used for fresh lychee in other importing countries
 10  
Ministry for Primary Industries  Risk Management Proposal for vapour heat treatment and cold treatment  on fresh Taiwan lychee  • 1 Submissions  
The Ministry for Primary Industries (MPI) invites comment from interested parties on the 
proposed amendment s to import health standards (IHSs ) 152.02: Importation and Clearance 
of Fresh Fruit and Vegetables into New Zealand  and Commodity Sub -class: Fresh 
Fruit/Vegetables Lychee, ( Litchi chinensis ) from Taiwan , which are supported by this risk 
management proposal . 
An import health standard  “specifies requirements to be met for the effective management of 
risks associated with importing risk goods, including risks arising because importing the 
goods involves or might involve an incidentally imported new organism.” (section 22 , 
Biosecurity Ac t 1993) . 
MPI would like feedback  on the following changes to the  above standards : 
1. Remov al of the suspended  vapour heat treatment  schedule for lychee s from Taiwan to 
manage Bactrocera dorsalis  and Zeugodacus cucurbitae  (syn. Bactrocera  cucurbitae ) 
a. Fruit pulp temperature at 46.5 °C or above for 20 minutes  
2. Addition of  a new combined treatment schedule for lychee s from Taiwan to manage 
Bactrocera  dorsalis  and Zeugodacus  cucurbitae  (syn. Bactrocera  cucurbitae ) 
a. Fruit pulp temperature raised from ambient to 46.2 °C or above for at least 20 
minutes followed by fruit pulp temperature lowered to 2 °C or below (within 6 
hours) for at least 42 hours  
Include the following  in your submission :  
• The title of the consultation document in the subject line of your email  
• Your name and title  
• Your organisation’s name (if applicable)  
Send submissions to  plantimports@mpi.govt.nz  by 5pm Friday , 24 February  2023.   
Feel free to include any  technical information  you have  that support s your submission. While 
we prefer email, if  you would like to send your submission by post, you can mail it  to: 
Horticulture Imports  
Animal and Plant Health  Directorate  
Biosecurity New  Zealand   
Ministry for Primary Industries  
PO Box 2526  
Wellington 6140  
New  Zealand   
Submissions received by  5pm Friday , 24 February 2023  will be considered during the 
amendment of the standard s. Submissions received after the clos ing date may be held on file 
for consideration when the standard s are next revised  or reviewed.   2 • Risk Management Proposal for vapour heat treatment and cold treatment  on fresh Taiwan lychee  Ministry for Primary Industries  Official Information Act 1982  
Please note that your submission is public information , and it is MPI policy to publish 
submissions and the review of submissions on the MPI website.  
Submissions  may also be the subject of requests for information under the Official 
Information Act 1982 (OIA). The OIA specifies that information is to be made available to 
requesters unless there are sufficient grounds for withholding it, as set out in the OIA. 
Subm itters may wish to indicate grounds for withholding specific information contained in 
their submission, such as information being  commercially sensitive or personal. Any decision 
to withhold information requested under the OIA is reviewable by the Ombudsman .   
Ministry for Primary Industries  Risk Management Proposal for vapour heat treatment and cold treatment  on fresh Taiwan lychee  • 3 1 General information  
1.1 Purpose  
(1) The purpose of this document is to:  
• Provide relevant background information on the biosecurity r isk of 
Bactrocera  dorsalis  and Zeugodacus  cucurbitae on fresh lychee s (Litchi chinensis ) 
from Taiwan , 
• Set out  the proposed amendments to the import requirements for fresh lychee s from 
Taiwan for the management of fruit flies,  
• Provide the rationale for the proposed amendment to the standards  and how it 
manage s risk, and  
• Ask for  feedback on the proposed amendment to the import requirement for fresh 
lychee s from Taiwan.  
1.2 Background   
(2) The standard Commodity Sub -class: Fresh Fruit/Vegetables Lychee, ( Litchi chinensis ) 
from Taiwan  was issued  on 5 October 2007  and last amended  on 24 August 2022 . This 
standard was issued under s  24A (formerly section  22) of the Biosecurity Act 1993 and 
applies to fresh lychee s that are imported into New  Zealand  from Taiwan . The standard 
152.02: Importation and Clearance of Fresh Fruit and Vegetables into New Zealand  
came into force on 7 October 1999 and was last amended o n 24 August 2022 . This 
standard was issued under section 24A of the Biosecurity Act  1993 . 
(3) In 2021, B. dorsalis was detected on vapour -heat-treated lychee s from Taiwan . MPI 
suspended the vapour heat treatment pathway , and we have reviewed  other treatment 
options.  We amended t he cold treatment schedules in the relevant standards in August 
2022  to manage the risk of B. dorsalis  and Z. cucurbitae on fresh lychee s from Taiwan.  
(4) Imports of vapour -heat-treated lychee s from Taiwan remain suspended. Our current 
proposal is to remove vapour heat treatment ( as a stand -alone treatment ) and , at the 
reques t of the national plant protection organisation  (NPPO) of Taiwan , add a combined 
treatment of vapour heat  followed by cold treatment . This  proposed amendment does 
not impact the cold treatment pathway.  
1.3 Timing and consultation  
(5) The proposed amendments to the import health standards Importation and Clearance of 
Fresh Fruit and Vegetables into New Zealand  (152.02) and Import Health Standard 
Commodity Sub -class: Fresh Fruit/Vegetables Lychee, ( Litchi chinensis ) from Taiwan  
were released for consultation on 16 January  2023 and will remain open for 
consultation until 24 February  2023. 4 • Risk Management Proposal for vapour heat treatment and cold treatment  on fresh Taiwan lychee  Ministry for Primary Industries  1.4 Background and context to consultation  
1.4.1 International  regulation of risk goods  
(6) “The World Trade Organi zation Agreement on the Application of  Sanitary and 
Phytosanitary Measures (SPS Agreement)  sets in place rules that protect each country’s 
sovereign right to take the measures necessary to protect the life or health of its people, 
animals, and plants , while at the same time facilitating trade.  It embodies and promotes 
the use of science -based risk assessments to manage the risks associated with the 
international movement of goods. The SPS Agreement guide s how New  Zealand  sets 
standards and makes decisions related to biosecurity. ” (MAF et al., 2 009, p. 1)  
(7) “In particular, [it is] important to maintain the standards of transparency and scientific 
rigour required by the SPS Agreement and to make decisions as quickly as possible. 
This will encourage other countries to comply with the rules of the SPS  Agreement and 
demonstrate that New  Zealand ’s strict controls are justified to countries that challenge 
them. ” (MAF et al., 2009 , p. 13) 
1.4.2 Domestic regulation of biosecurity risks associated with craft arrivals  
(8) The New  Zealand  biosecurity system is regulated  through the Biosecurity Act 1993 (the 
Act). Section 22 describes an import health standard and requires all risk goods entering 
New  Zealand  to be managed by one . MPI is the New  Zealand  government ministry 
responsible for maintaining biosecurity standards for the effective management of risks 
associated with the importation of risk goods and craft into New  Zealand  (Part 3, 
Biosecurity Act 1993). We are  committed to the principles of transparency and 
evidence -based technical justification for all phytosanitary measures, new and amended, 
imposed on importing pathways. We periodically review all import health  standards, 
related documents and other standards so that the legal requirements are clear , and 
information is consistently presented and as easy as possible to understand.  
2 Biosecurity risk associated with fresh lychee s from Taiwan  
(9) Measures are needed to manage the biosecurity risk posed by the tephritid fruit flies 
B. dorsalis  and Z. cucurbitae  on fr esh lychee s. The conclusions we came to in our  2007 
Import Risk Analysis: Litchi chinensis  (Litchi) Fresh Fruit  from Taiwan  about  the 
biosecurity risk of these fruit flies have not changed . 
a. Bactrocera dorsalis  (oriental fruit fly) is a pest of concern on fresh lychee s from 
Taiwan . 
i. It is present and widespread in Taiwan (MPI, 2007; Leblanc, 2020).  
ii. It is a regulated quarantine pest and absent from New  Zealand  (ONZPR 2022).  
iii. Litchi chinensis  is a host of the oriental fruit fly (MPI, 2007).  
iv. This fruit fly  attacks  over 300 cultivated and wild fruits (Mau and Matin, 
1992 in MPI, 2007) including apple s, avocado es, citrus, cucumber s, 
eggplant s, pumpkin s, stonefruit  and tomato es (Leblanc 2020).   
Ministry for Primary Industries  Risk Management Proposal for vapour heat treatment and cold treatment  on fresh Taiwan lychee  • 5 v. Oriental fruit flies  are strong fliers and are highly mobile (Chu and Chiu, 
1989, from MPI, 2007) with a maximum recorded flying distance of  265 km. 
b. Zeugodacus  cucurbitae (melon fly) is a pest of concern on fresh lychee s from 
Taiwan . 
i. It is present  and widespread in Taiwan (MPI , 2007 ; Bakri , 2020 ). 
ii. It is a regulated quarantine pest  and absent from New  Zealand  (ONZPR , 
2022) . 
iii. Litchi chinensis  is a host of the melon fly (MPI , 2007).  
iv. The m elon fly  is a very serious pest of cucurbit crops and has been recorded 
from over 125 plants. The p rimary hosts are cucurbits . However , other crops 
affected include apple s, avocado es, beans, blueberries, feijoa s, orange s, 
passionfruit, peach es, pear s, pomelo s and tomato es (MPI, 2007 ; Bakri , 2020).  
v. Melon flies  are strong fliers , are very mobile  and can readily travel 30 –50 km 
(Kawai et al. , 1978  in MPI, 2007 ). 
c. The likelihood of entry for both fruit flies is very high (MPI , 2007).  
d. It is highly likely that both flies would be exposed to suitable hosts in many parts 
of New  Zealand  (MPI , 2007). Adult longevity ( up to 222 days) is likely to enhance 
the likelihood of adult flies finding a mate. There would be no shortage of host 
plants a vailable all year round. Fruit left on the ground serve s as a major breeding 
site and reservoir population for fruit fl ies overseas  (Liquido , 1991  in MPI, 2007 ). 
e. It is highly likely that climatic conditions would facilitate the establishment of both 
flies, particularly in Auckland and the upper North Island (MPI , 2007).  
(10) The presence and establishment of tephritid fruit flies would have a significant impact 
on New  Zealand ’s economy . 
a. B. dorsalis  or Z. cucurbitae detection s need to be reporte d internatio nally and w ill 
likely result in reduced market access for New  Zealand  fruit fly host material  (MPI , 
2007) .  
b. There will be a significant ly reduc ed harvest for infested crops if fruit fl ies become  
establish ed (MPI , 2007).  
c. Many horticultural commodities are a t risk (see hosts and affected plants above).  
The financial impact of a  fruit fly  incursion is estimated to cost between $2 million 
and $430 million per year ( KVH , 2014).  
d. Apples  can be infested with both flies and  were the second highest fresh fruit 
export from New  Zealand  in 2020, worth $876.3 million ( Plant & Food Research , 
2020) . Total fresh fruit exports were worth $3.7 billion, and fresh vegetable  exports 
were  worth $301 million ( Plant & Food Research , 2020).  6 • Risk Management Proposal for vapour heat treatment and cold treatment  on fresh Taiwan lychee  Ministry for Primary Industries  (11) Tephritid  fruit flies are not sufficiently managed or detected by basic measures alone or 
targeted measures.  
a. B. dorsalis  is one of the most destructive insect pests of tropical and subtropical 
fruits and vegetables. It is highly polyphagous and highly adapt able to various 
climates, which has allowed it to spread to temperate areas.  Eggs laid in a lychee 
fruit just before  harvest and larvae feeding in fruit are likely to survive export to 
New  Zealand . If travelling by air, all life stages could survive and enter the 
country.  
b. Z. cucurbitae  is a major, well -established pest on many fruit species in Taiwan.  
Eggs laid in a lychee fruit before  harvest would be expected to survive export to 
New  Zealand  as either eggs or larvae. If travelling by air, all life stages could 
survive and enter the country.  
(12) Given the biosecurity risks posed by the fruit flies B. dorsalis  and Z. cucurbitae  on fresh 
lychee s (as outlined in this document), we are  satisfied that the proposed requirements 
are consistent with New  Zealand ’s obligations under the SPS Agreement . 
3 Proposed changes to the requirements for fresh lychees 
from Taiwan  
(13) We propose removing the (currently suspended) vapour heat treatment schedule for 
lychee s from Taiwan (f ruit pulp temperature at 46.5 °C or above for 20 minutes ). 
(14) We also propose add ing a combined treatment schedule of vapour heat followed by  cold 
treatment for lychee s from Taiwan  (fruit pulp temperature raised from ambient to 
46.2 °C or above  for at least 20 minutes followed by fruit pulp temperature lowered to 
2 °C or below , within 6 hours , for at least 42 hours ). During  vapour heat treatment, the 
chamber should  remain at 46.7°C with saturated humidity for the duration of the 
treatment.  
4 Ratio nale for the proposed amendment to the lychee  
standards   
(15) In our  2007 Litchi chinensis  import risk analysis , we used efficacy data from 
experiments on vapour heat treatment on mango  pulp, bitter gourd s and netted melon s 
as a proxy for lychee s. Vapour heat treatment (fruit pulp temperature at 46.5 °C or 
above for 20 minutes) was previously accepted to manage tephritid fruit flies on this 
pathway .  
a. There are currently no active vapour heat treatment pathways for lychee s 
worldwide (MPI, 2022b; Appendix 1) . 
i. The vapour heat treatment pathway between Hawaii and the continental 
United States was inactive  as of 2016  (Dohino et al., 2016) , as it has  likely  
been replaced by irradiation treatment (Follett and Weinert, 2012).    
Ministry for Primary Industries  Risk Management Proposal for vapour heat treatment and cold treatment  on fresh Taiwan lychee  • 7 b. The presence of live fruit flies on vapour -heat-treated lychee s from Taiwan arriving 
in New  Zealand in 2021 indicates that this treatment is not sufficient to mitigate the 
risk of fruit flies on this pathway.  
(16) Following the suspension of the vapour heat treatment pathway, the NPPO of Taiwan 
asked us to consider vapour heat treatment followed by cold treatment as an alternative 
treatment.  
(17) The NPPO of Taiwan  provided MPI with a scientific re port Vapor Heat & Cold 
Combined Treatment as a Quarantine Treatment for Disinfestation of Oriental Fruit 
Flies ( Bactrocera dorsalis  Hendel) in Lychees  (BAPHIQ, 1987 ; MPI, 2022b ). This 
report  used efficacy data o n Bactrocera  dorsalis . Based on the technical advice from the 
data in this report on both  medium and large -scale trials, vapour heat treatment  at a 
minimum 46.2  °C for at least 20 minutes followed by cold storage for 42 hours at 2  °C 
(within 6 hours of vapour heat treatment) will control all  life stages of B. dorsalis . 
a. Zeugodacus  cucurbitae  will also be controlled by this measure as it is less heat 
tolerant  than Bactrocera  dorsalis  (Kaneyuki et al., 2016).   
(18) Based on the points mentioned in paragraph  17, we have  concluded that a combined 
vapour heat treatment followed by  cold treatment schedule will manage the risk of all 
life cycle stages of Bactrocera  dorsalis  and Zeugodacus  cucurbitae  on fresh lychee s 
from Taiwan . 
5 Feasibility of the proposed change to the standard  
(19) The proposed schedule for combined vapour heat followed by cold treatment is also 
used by  Japan and South Korea  for fresh lychee s from Taiwan .  
(20) We do not expect these requirements to create any additional costs for importers.   8 • Risk Management Proposal for vapour heat treatment and cold treatment  on fresh Taiwan lychee  Ministry for Primary Industries  6 References  
Bakri, A (2020 ) Bactrocera  cucurbitae  (melon fly). Crop Protection Compendium.  CABI; 
Wallingford, UK. DOI:10.1079/CPC.17683.20210104850. 
https://www.cabi.org/isc/datasheet/17683  Accessed November  2022.  
BAPHIQ  (1987) Vapor Heat & Cold Combined Treatment  as a Quarantine Treatment  for 
Disinfestation of Oriental Fruit Flies ( Bactrocera dorsalis  Hendel) in Lychees . Bureau of 
Animal and Plant Health Inspection and Quarantine, Taiwan.  
Chu, Y I; Chiu, H T (1989) The re -establishment of Dacus dorsalis  Hendel (Diptera: 
Tephritidae) after its eradication on Lambay Island. Chinese Journal of Entomology , 9(2): 
217-230. 
DAFF (2022 ) Australian Biosecurity Import Conditions system (BICON). Depar tment of 
Agriculture, Fisheries and Forestry ; Canberra, ACT, Australia. 
https://bicon.agriculture.gov.au/BiconWeb4.0  Accessed November  2022. 
Dohino, T ; Hallman , G J;  Grout , T G;  Clarke,  A R;  Follett, P A; Cugala,  D R;  Tu, D M;  
Murdita,  W; Hernandez,  E; Pereira,  R; Myers , S W.  (2016) Phytosanitary treatments against  
Bactrocera dorsalis  (Diptera: Tephritidae): Current situation  and future prospects . Journal of 
Economic Entomology , 110(1) : 67-79. 
Entomological Society of America (2 March 2022) ‘Spongy Moth ’ adopted  as new common 
name  for Lymantria dispar . Entomological Society of America; Annapolis, Maryland, USA.  
https://entsoc.org/news/press -releases/spongy -moth -approved -new-common -name -lymantria -
dispar Accessed November 2022 . 
Follett, P A & Weinert , E D (2012) Phytosanitary irradiation of fresh tropical commoditie s in 
Hawaii: Generic treatments, commercial adoption, and current issues. Radiation Physics and 
Chemistry , 81: 1064 -1067. DOI: 10.1016/j.radphyschem.2011.12.007  
Kaneyuki, M; Kobashiqawa, Y; Tamamoto, T; Kikukawa, K; Miyazaki, I; Adachi, H (2016) 
Effect of Age and Feeding on Heat Tolerance in Each Larval Instar Period of Bactrocera 
dorsalis  and Bactrocera cucurbitae  (Diptera: Tephritidae). Research Bulletin of the Plant 
Protection Service , 52: 29-36. 
Kawai, A; Iwahashi, O; Ito, Y (1978) Movement of the steri lised melon fly from Kume 
Islands to adjacent islets. Review of Applied Entomology , 67: 5195.  
KVH (2014) Financial impact of a fruit fly incursion to New  Zealand ’s kiwifruit industry. 
Kiwifruit Vine Health; Mount Maunganui, NZ. https://kvh.org.nz/vdb/document/98983  
Accessed November  2022.  
Leblanc, L (2020) Bactrocera dorsalis  (oriental fruit fly). Crop Protection Compendium.  
CABI; Wallingford, UK. DOI:10.1079/CPC.17685.20210102450. 
https://www.cabi.org/isc/datasheet/17685  Accessed November  2022.   
Ministry for Primary Industries  Risk Management Proposal for vapour heat treatment and cold treatment  on fresh Taiwan lychee  • 9 Liquido, N J (1991) Fruit on the ground as a reservoir of resident melon fl y (Diptera: 
Tephritidae) populations in papaya orchards. Environmental Entomology , 20: 620 -625. 
MAF ; MFAT ; FSA (2009) Balance in Trade.  Ministry of Agriculture and Forestry, Ministry 
of Foreign Affairs and Trade, New  Zealand , Food Safety Authority; Welling ton, NZ. 
https://www.mpi.govt.nz/dmsdocument/12576 -balance -in-trade . 
Mau, R F L ; Matin, J L (1992) Bactrocera dorsalis Featured Creatures . Crop Knowledge 
Master.  Extension entomology & UH -CTAHR Integrated Pest Management Program. 
University of Hawaiʻi; Honolulu, Hawaii, USA. 
www.extento.hawaii.edu/kbase/crop/Type/bactro_d.htm . Accessed Octo ber 2022.  
MPI (2007) Import Risk Analysis: Litchi chinensis (Litchi) Fresh Fruit from Taiwan . Ministry 
for Primary Industries; Wellington, New  Zealand . 
https://mpi.govt.nz/dmsdocument/2883/direct  Accessed November  2022. 
MPI (202 2a) Importation and Clearance of Fresh Fruit and Vegetables into New  Zealand . 
Ministry for Primary Industries; Wellington, NZ. 
https://www.mpi.govt.nz/dmsdocument/1147 -Importation -and-Clearance -of-Fresh -Fruit -and-
Vegetables -into-New -Zealand -Import -Health -Standard  Accessed November  2022. 
MPI (2022 b) Technical advice on: Vapour heat followed by cold treatment for management 
of fruit flies in lychees from Taiwan . Ministry for Primary Industries; Wellington, New 
Zealand.  
ONZPR (2022) Official New Zealand  Pest Register . Ministry for Primary Industries; 
Wellington, NZ. https://pierpestregister.mpi.govt.nz/  Accessed October 2022.  
Plant & Food Research  (2020) Fresh Facts : New Zealand  Horticulture . The New  Zealand  
Institute for Plant and Food Research Ltd, Auckland, New  Zealand . 
https://www.freshfacts.co.nz/files/freshfacts -2020.pdf  Accessed October  2022.  
USDA APHIS (2016)  Treatment Manual.  United States Department of Agriculture Animal 
and Plant Health Inspection Service; Washington, D.C., USA. 
https://www.aphis.usda.gov/import_export/plants/man uals/ports/downloads/treatment.pdf  
Accessed November 2022 . 
  10 • Risk Management Proposal for vapour heat treatment and cold treatment  on fresh Taiwan lychee  Ministry for Primary Industries  Appendix 1: Vapour heat treatment used for fresh lychee in 
other importing countries  
Importing 
Country  Country of 
origin  Pests  Treatment schedule  Source  
Japan  
 Taiwan  B. dorsalis 
complex  46.2 °C, hold for 
20 min, followed by cold 
treatment at 2 °C for 
42 h MPI (2007)  
Korea  Taiwan  B. dorsalis 
complex  46.2 °C, hold for 
20 min, followed by cold 
treatment at 2 °C for 
42 h MPI (2007)  
USA Hawaii  B. dorsalis  
Ceratitis  
capitata  47.2 °C in 1  h, hold for 
20 min USDA APHIS (2016) 
T106 -f  
Australia  China  
 B. dorsalis  
 47 °C (fruit core 
temperature) or above 
for 15 minutes ; or   
46°C (fruit core 
temperature) or above 
for 20 minutes.   Under review ( MPI, 
2022 b) 
 
   
Ministry for Primary Industries  Risk Management Proposal for vapour heat treatment and cold treatment  on fresh Taiwan lychee  • 11 References  for Appendix 1  
DAFF (2022 ) Australia n Biosecurity Import Conditions system (BICON). Department of 
Agriculture, Fisheries and Forestry ; Canberra, ACT,  Australia . 
(https://bicon.agriculture.gov.au /BiconWeb4.0  Accessed November 2022 . 
MPI (2007) Import Risk Analysis: Litchi chinensis (Litchi) Fresh Fruit from Taiwan . Ministry 
for Primary Industries; Wellington, New  Zealand. 
https://mpi.govt.nz/dmsdocument/2883/direct Accessed November 2022 . 
MPI (2022 b) Technical advice on: Vapour heat followed by cold treatment for management 
of fruit flies  in lychees from Taiwan . Ministry for Primary Industries; Wellington, New 
Zealand.  
USDA APHIS (2016) Treatment Manual . United States Department of Agriculture (USDA) 
Animal and Plant Health Inspection Service; Washington, D.C., USA. 
https://www.aphis.usda.gov/import_export/plants/manuals/ports/downloads/treatment.pdf  
Accessed November 2022 .