Risk Management Proposal:  
Amendment to the import health standard 
Dried and Preserved Plant Materials   
(DPP .IHS) 
 
 
  Prepared for public consultation  
by Plant Product Imports  
Animal and Plant Health Directorate  
 
    
18 October  2023 
i Disclaimer  
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, inte rpretation,  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  
   
ii Contents  Page 
1 General information 3 
1.1 Purpose 3 
1.2 Timing and consultation 3 
2 Proposed changes to the standard 3 
3 Rationale for the proposed changes  3 
3.1 Background 3 
3.2 Pest surveys 4 
3.3 Assessment of invertebrates found on mats 4 
4 Conclusion 7 
5 Appendices  8 
5.1 Appendix 1: Proposed tapa and fine mats import requirements  8 
5.2 Appendix 2: Invertebrates identified to species in 2022 survey 9 
5.3 Appendix 3: Invertebrates identified to species in 2010 survey 10 
6 References  11  
Ministry for Primary Industries    RMP: Amendment  to Dried and Preserved Plant Material • 3 
 1 General information 
1.1 Purpose 
(1) The purpose of this document is to:  
a) Outline  the proposed changes to the  import health standard Dried and 
Preserved Plant Material ,  
b) Explain why the proposed changes are necessary,  and 
c) Ask for feedback on the proposed change s. 
1.2 Timing and consultation  
(2) The proposed changes  to Dried and Preserved Plant Material  were released for 
consultation on 2 Novem ber 2023 and will remain open for consultation until  14 
December 2023 . 
 
2 Proposed changes  to the standard  
(3) We propose removing  the import requirements for all consignments of Pacific -
style handwoven mats or tapa cloth mats (including fine mats ) from Part 4.5 of 
Dried and Preserved Plant Material . This involves:  
a) Removing the requirement for  an official phytosanitary certificate or 
inspection in New Zealand; and  
b) Removing the requirement for mats to be made from specific plants . 
(4) The proposed changes are outlined in Appendix 1.  
 
3 Rationale for the proposed changes  
3.1 Background  
(5) Fine mats and tapa mats are cloths of cultural significance made from plant 
material by Pacific people using traditional methods. Fine mats are made from Pandanus  leaves , whereas tapa mats are made from the pounded inner bark of 
trees , such as paper mulber ry (Broussonetia papyrifera) and breadfruit  
(Artocarpus altilis ). Both mats are used in ceremonies such as funerals, 
weddings, births, and royal events  and as clothing for formal occasions.  
(6) Our current  commodity description defines  fine mats as mats made from  
Pandanus  species. This prevents people importing fine mats made from other 
plant s. We propose changing this  to “Clean Pacific -style, handwoven or tapa 
cloth mats (including fine mats) ”. This will make it eas ier to import fine mats 
made from any plants . 
(7) Currently, we require tapa and fine mats to be  inspected for quarantine pests 
and seeds and to be issued with a phytosanitary certificate before they are  
Ministry for Primary Industries    RMP: Amendment  to Dried and Preserved Plant Material • 4 
 export ed. The offshore phytosanitary certification varies from inspection to 
fumigation . An accompanied single mat smaller than 2 m2 is exempt from these 
requirements.  
(8) On arrival in New Zealand, we currently require mats without a phytosanitary 
certificate to be inspected or fumigated with methyl bromide depending on the 
size of the mat. However , due to environmental regulations and restrictions on 
the fumigant, contaminated mats are often treated with heat. Heat treatment 
damages the mats, and importers have raised concerns about this treatment . 
3.2 Pest surveys 
(9) To identify the organism s associated with tapa mats and determine the level of 
biosecurity risk on the tapa mat pathway , we surveyed the pests on mats  in 
2010 and 2022.  
(10) Our border staff inspected half of all mats between September and November 
2022 and sent any invertebrates to our  lab for identification. Border staff found 
no seeds on any mats and no invertebrates on approximately two thirds of the 
100 mats  they inspected.  The other mats were found to contain contaminant 
invertebrates. Twelve species of  invertebrate s were found . These species are 
common  cosmopolitan species  that are  often found across several  pathways  
(Appendix 2). The m ost common invertebrate s were bookl ice (psocids ). These 
tiny invertebrates are common in houses in New Zealand, and booklice can be 
found on almost every import ed commodity , including  cardboard , computers , 
and passenger bags .  
(11) In 2010 , border staff inspected a total of 1,227 tapa and fine mats. 253 mats 
had invertebrates (dead or alive). Our lab identified the species for 26 of the 
invertebrates. Of those 26, eight  were invertebrates that Biosecurity New 
Zealand has previously concluded have the potential to cause harm in 
New Zealand (Appendix 3).  
3.3 Assessment  of invertebrates  found on mats  
(12) We assessed  whether these eight invertebrates (listed in Table 1) would be 
able to establish a population  in New Zealand and, if so, whether they would 
have adverse impacts . 
(13) This information helped us to determine the level of biosecurity risk on the tapa 
mat pathway and to propose appropriate measures to mitigate the risk.  
(14) We found that the overall risk of invertebrates  becoming established  in 
New Zealand through the tapa mat pathway and causing  significant impact s is 
sufficiently  low that  there  is no justification for retaining the current import 
requirements for tapa and fine mats.  
(15) In our assessment, we considered:  
a) the number/frequency of  interceptions  of each pest  through the tapa mat 
pathway ,  
b) the likelihood of  the pest to establish  a population in New Zealand through 
the tapa mat pathway , and  
c) the potential economic and environmental impact  if it becomes established.   
Ministry for Primary Industries    RMP: Amendment  to Dried and Preserved Plant Material • 5 
  
Table 1: Assessment of invertebrate s found on mats  
Invertebrates  Assessment  
Anoplolepis 
gracilipes  
(yellow crazy ant)  
 
Paratrechina 
longicornis  
(black crazy ant , 
longhorn crazy ant ) 
 
Tapinoma 
melanocephalum  
(ghost ant)  
 
 We assessed  three ant species  (Anoplolepis gracilipes, 
Paratrechina longicornis and Tapinoma melanocephalum ). The 
overall risk (based on likelihood of establishment and impact) of 
these ants on the tapa mat pathway is  low.  
Records of pest interceptions  on the tapa mat pathway shows that 
we have only  ever intercepted single  ants or a few workers of 
these species.  
Single or multiple workers cannot  establish a new colony. Ants can 
only establish a population if  a mated queen or colony enter s New 
Zealand.  
Mated queens and colonies have never been found on this 
pathway and are unlikely to be associated with th ese product s. 
Mated queens live in the colony , and a colony can easily be 
detec ted on the mat due to the number of ants. It  is unlikely  that 
these ants can establish a population in New Zealand via the tapa 
mat pathway.  
If black crazy ants or ghost ants  become established in 
New Zealand, they will be limited to warm locations in the  North 
Island, and our assessment is their  impact would be low. 
One researcher  predicted that yellow crazy ants  could establish 
populations  in certain parts of  New Zealand (Chen, 2008) . 
However,  another researcher  suspected  these ants  may not be 
able to establish a permanent population  in New Zealand and 
classified th em as a “potential ephemeral species ”, whereby the 
species fails to sustain itself beyond a few generations before 
becoming locally  extinct  (Lester, 2005) . Based on the available 
evidence, if yellow crazy ants establish a population, they a re likely 
to be limited to urban areas in isolated locations in North Island, as 
New Zealand’s summer temperatures are not optimal for them 
(Abbott et al. , 2005) . 
Yellow crazy ants  feed on other  insect s, smal l animals, honeydew 
and plant nectar . If these ants  establish a population in New 
Zealand, they could adversely affect some native fauna  and flora 
although their low populations due to suboptimal climatic 
conditions would limit their impact.  
We do not consider that these ants can establish a population in 
New Zealand via this pathway.  
Adoretus versutus  
(rose beetle, India 
rose beetle)  Eggs, larvae , and pupae of rose beetles  are unlikely to enter on  
the tapa mat pathway as these life stages live underground.  
Adult  rose beetles  could hitchhike on mats and enter on the 
pathway. Two adults (sex unknown) were intercepted (one each 
on two occasions) in the 2010 survey. We found  none of these 
beetles  in the 2022 survey.   
Ministry for Primary Industries    RMP: Amendment  to Dried and Preserved Plant Material • 6 
 Considering the low number s of rose beetles  arriving through this 
pathway and the unfavourable climat e in New Zealand, the beetles  
are unlikely to establish a population. If they do establish  a 
population, the beetles will likely be limited to isolated patches in 
the Northland and Auckland regions w here there are warm 
temperatures.  The beetle has only managed to establish  
populations  in tropical countries (Phillips et al.,  2018; Roigé and 
Phillips , 2021)  so far, and none of these countries have similar 
climates  to New Zealand.  
We think t he impact of  rose beetles  in New Zealand would be very 
low. This is  because several of th e beetles ’ main host plants , such 
as cocoa and bele are not grown commercially in New Zealand.  
Lophocateres 
pusillus  
(Siamese grain 
beetle)  In the past, we intercepted a dult Siamese grain beetles on tapa 
cloth on 17 occasions. On 10 of those occasions, we intercepted 
multiple adults (sex unknown) ( LIMS , 2023) . 
Siamese grain beetles are native to tropical areas but  can survive  
in temperate areas , where they are mainly found indoors (in 
heated environments ). The t otal development duration (egg  to 
adult) varies  from 180 days at 20° C to 49 days at 35° C (Halstead , 
1968) . As a stored product pest, t hey could  potentially  establish 
populations in warehouses and residential houses in New Zealand 
where the temperatures are suitable enough for the beetles to 
breed.  
If they establish, w e expect Siames e grain beetles to have a very 
low impact in New Zealand because routine control measures and 
storage hygiene applied for other stored product pests  that are  
already in New Zealand will also be effective against  these 
beetles.  
Trogoderma 
variabile  
(warehouse beetle)  Larvae of w arehouse beetle are  the likely life stages associated 
with tapa mats. D uring the 2010 survey, we only found a single 
larva on tapa mats . We did not find any  in the 2022 survey. For 
this insect  to establish a population, multiple warehouse beetles 
need to enter New  Zealand.  
Considering the low numbers of warehouse beetles on tapa mats 
coming into New  Zealand, they are unlikely to establish a 
population via this pathway.  
The larvae feed on stored food products, animal feed and dead 
insects/animals. Warehouse beetles are a minor pest in the USA 
and Canada (Nardi and Vomero, 2017)  where it has established.  
Ectopsocus 
maindroni  
(barklice) 
 
Ectopsocus 
richardsi  
(barkl ice) We assessed two barklice (Ectopsocus maindroni  and 
E. richardsi ).  
We often find E. maindroni  on tapa mats , and we expect that they 
can establish populations in certain parts of New Zealand.  
We often find single E. richardsi  on tapa mats. Considering the low 
numbers of  E. richardsi , they are  unlikely to establish a population 
via this pathway.  
Barklice generally feed on lichen, fungi , organic matter and dead 
insects (Smithers , 1972) . They  are generally not economically 
important pests (Smithers , 1972) .   
Ministry for Primary Industries    RMP: Amendment  to Dried and Preserved Plant Material • 7 
 We found no  information on the impact of these barklice  in the 
literature . This indicates that they do not cause significant 
problems.   
 
 
4 Conclusion  
(16) We found that the overall risk of invertebrates becoming established in New 
Zealand through the tapa mat pathway and causing significant impacts is 
sufficiently low that there is no justification for retaining the current import requirements for tapa and fine mats.  
   Question for your submission  
Do you agree with our reasoning for removing the import requirements  on this 
pathway ? If you do not agree, please provide your reasons ?  
  
Ministry for Primary Industries    RMP: Amendment  to Dried and Preserved Plant Material • 8 
 5 Appendices  
5.1 Appendix 1: Proposed tapa and fine mats import requirements 
A. Current import requir ements  
 
B. Proposed import requirements  
4 Clean Pacific style, hand woven 
or tapa cloth mats (including fine 
mats.)  All consignments  No certification or inspection requirements  
 
  
 
Ministry for Primary Industries    RMP: Amendment  to Dried and Preserved Plant Material • 9 
 5.2 Appendix 2: Invertebrates identified to species  in 2022 survey 
Scientific name  Common name  Family  
Ahasverus advena  foreign grain beetle  Silvanidae  
Blattisocius dentriticus  common blattisociid mite  Parasitiformes  
Cheyletus malaccensis  predatory mite  Cheyletidae  
Cimex lectularius    Cimicidae  
Lepisma saccharina  silverfish  Lepismatidae  
Liposcelis bostrychophila  banded psocid  Liposcelididae  
Liposcelis corrodens    Liposcelididae  
Liposcelis entomophila  grain psocid  Liposcelididae  
Liposcelis paeta  booklice  Liposcelididae  
Liposcelis pubescens  booklice  Liposcelididae  
Monomorium pharaonis  pharaoh ant  Formicidae  
Spinibdella bifurcata    Trombidiformes  
   
Ministry for Primary Industries    RMP: Amendment  to Dried and Preserved Plant Material • 10 
 5.3 Appendix 3: Invertebrates identified to species  in 2010 survey 
Name  Common name  Family  
Adoretus versutus  rose beetle, India rose 
beetle  Scarabaeidae  
Anoplolepis gracilipes  yellow crazy ant  Formicidae  
Anthrenus verbasci  varied carpet beetle  Dermestidae  
Aphodius lividus  dung beetle  Scarabaeidae  
Ctenolepisma longicaudata  gray silverfish  Lepismatidae  
Ectopsocus maindroni  barklice  Ectopsocidae  
Ectopsocus richardsi  barklice  Ectopsocidae  
Ectopsocus spilotus  barklice  Ectopsocidae  
Lasioderma serricorne  cigarette beetle  Ptinidae  
Liposcelis entomophilus  Booklice, grain psocid  Liposcelidae  
Lophocateres pusillus  Siamese grain beetle  Trogossitidae  
Monomorium liliuokalanii  ant Formicidae  
Monomorium pharaonis  pharaoh ant  Formicidae  
Oecobius marathaus  wall spider  Oecobiidae  
Opopaea concolor  goblin spiders  Oonopidae  
Opopaea deserticola  goblin spider  Oonopidae  
Oryzaephilus surinamensis  sawtoothed grain beetle  Silvanidae  
Paratrechina longicornis  longhorn crazy ant, black 
crazy ant  Formicidae  
Periplaneta australasiae  Australian cockroach  Blattidae  
Pheidole megacephala  bigheaded ant  Formicidae  
Rhyzopertha dominica  lesser grain borer  Bostrichidae  
Scytodes fusca  spitting spiders  Scytodidae  
Tapinoma melanocephalum  ghost ant  Formicidae  
Trogoderma variabile  warehouse beetle  Dermestidae  
Withius piger  lazy chelifer  Withiidae  
Xestaspis loricata  spider  Oonopidae  
 
   
Ministry for Primary Industries    RMP: Amendment  to Dried and Preserved Plant Material • 11 
 6 References  
Abbott, K; Harris, R; Lester, P (2005) Invasive ant risk assessment: Anoplolepis gracilipes. 
Landcare Research contract report for Biosecurity New Zealand, Ministry of Agriculture and 
Forestry. Wellington, New Zealand. 
Abbott, K L; Green, P T; O'Dowd, D J (2014) Seasonal shifts in macronutrient preferences in 
supercolonies of the invasive Y ellow C razy A nt A noplolepis gracilipes (S mith, 1857)(H 
ymenoptera: F ormicidae) on C hristmas I sland, I ndian O cean. Austral Entomology 53(3): 
337-346. 
AntWeb (2023) California Academy of Sciences. https://www.antweb.org/  Accessed 13 April 
2023 
Cebolla, R., Pekár, S. & Hubert, J. (2009) Prey range of the predatory mite Cheyletus 
malaccensis  (Acari: Cheyletidae) and its efficacy in the control of seven stored- product 
pests. Biological Cont rol, 50, 1– 6. https://doi.org/10.1016/j.biocontrol.2009.03.008  
Chen, Y (2008) . Global potential distribution of an invasive species, the yellow crazy ant 
(Anoplolepis gracilipes) under climate change. Integrative zoology 3(3): 166 -175. 
Gorham, JR. ed. (1987). Insect and mite pests in food. An illustrated key. USDA ; USA  
Global Invasive Species Database (2023) 100 of the World's Worst Invasive Alien Species. 
Accessed 17 April 2023. 
Halstead, D (1968) Some observations on the biology of Lophocateres pusillus 
(Klug)(Coleoptera: Trogositidae). Journal of Stored Products Research 4(3): 197- 202. 
Lee, C -Y; Yang, C -C S (2022) Biology, ecology, and management of the invasive longlegged 
ant, Anoplolepis gracilipes. Annual Review of Entomology 67: 43 -63. 
Lester, P J (2005) Determinants for the successful establishment of exotic ants in New Zealand. Diversity and Distributions 11(4): 279 -288. 
LIMS (2023) Laboratory Information Management System. Ministry for Primary Industries 
internal database. Accessed 18 April 2023 
Lukás, J., Stejskal, V., Jarosík, V., Hubert, J. & Zdárková , E. (2007) Differential natural 
performance of four Cheyletus predatory mite species in Czech grain stores. Journal of Stored 
Products Research, 43, 97 –102. https://doi.org/10.1016/j.jspr.2005.12.002  
Nardi, G; Vomero, V (2017) Trogoderma variabile Ballion, 1878: a possible new pest of 
Italian entomological collections (Coleoptera: Dermestidae). Fragmenta entomologica 49(1): 
85-88. 
O'Dowd, D J; Green, P T; Lake, P S (2003) Invasional ‘meltdown’on an oceanic island. 
Ecology letters 6(9): 812 -817. 
Phillips, C B; Kean, J M; Vink, C J; Berry, J A (2018) Utility of the CLIMEX ‘match climates 
regional’ algorithm for pest risk analysis: an evaluation with non -native ants in New Zealand. 
Biological invasions 20(3): 777- 791. 
Plentovich, S; Russell, T; Fejeran, C C (2018) Yellow crazy ants (Anoplolepis gracilipes) reduce numbers and impede development of a burrow -nesting seabird. Biological invasions 
20(1): 77 -86. 
Roigé, M; Phillips, C B (2021) Validation and uncertainty analys is of the match climates 
regional algorithm (CLIMEX) for Pest risk analysis. Ecological Informatics 61: 101196.  
Toldi M, Faleiro DCC, Da Silva GL and Ferla, NJ (2017). Life cycle of the predatory mite Cheyletus malaccensis  (Acari: Cheyletidae) fed on Poultry Red Mite Dermanyssus gallinae  
(Acari: Dermanyssidae). Systematic & Applied Acarology  22(9): 1422–1430. (PDF) Life  
Ministry for Primary Industries    RMP: Amendment  to Dried and Preserved Plant Material • 12 
 cycle of the predatory mite Cheyletus malaccensis (Acari: Cheyletidae) fed on Poultry Red 
Mite Dermanyssus gallinae (Acari: Dermanyssidae) (researchgate.net) 
Wetterer, J K (2005) Worldwide distribution and potential spread of the long- legged ant, 
Anoplolepis gracilipes(Hymenoptera: Formicidae). Sociobiology 45(1): 77- 97.