International Plant Protection Convention
IFQRG 11 (2013) meeting notes on draft ISPM15 treatment criteria
TPFQ_2013_Dec_05
Agenda item: 4.1
IFQRG 11 (2013) MEETING NOTES ON DRAFT ISPM15 TREATMENT CRITERIA
(last updated 18 November 2013)
Suggestions from IFQRG on draft ISPM 15 treatment criteria
The following suggestions have been made by IFQRG 11 for the draft on ISPM 15 criteria for
treatments:
1.
Test units should be clearly identified for each step of the process.
2.
Provisions allowing for rendering insects infertile should be reconsidered as they would allow
for the survival of vectors of pests (e.g. Monochamus).
3.
Consider reordering step 2 and step 3.
4.
In step 4 delete text from “most likely to result” to “normally expected in untreated wood”.
5.
In step 4 reconsider the sentence “Parameters used for testing may...”.
6.
In step 4 clearly indicate whether testing of 60 test units should be performed as a single test or
as 60 repetitions.
7.
In step 4 not provide for 3 repetitions of 20 test units.
8.
In step 4 clarify whether the phrase “statistical reliability of 0.95 at a 95 % confidence level” is
correct.
9.
Clarify whether different strains of pest should be used for testing.
10.
Delete the example in the description of ‘N’.
11.
Clarify whether ‘V” is a constant value of 300.
12.
In step 4 clearly state that the number of insects used for testing should never be lower than 60.
13.
Reconsider the need for inclusion of Cardiff Protocol in the draft and clarify whether (and to
what level) it increases the statistical reliability of tested treatments.
Comments on the Draft Text:
Step 1: Screening
The screening is intended to gather data under laboratory conditions to identify the effective treatment
level for the most tolerant pest at the most tolerant life-stage to be used for further testing in Steps 2, 3
and 4. Testing should be conducted on any species from each of the Bostrychidae, Buprestidae,
Cerambycidae, Scolytinae and Siricidae; a Heterobasidion species; and Bursaphelenchus xylophilus.
To identify the effective treatment level for the most resistant life stage of a pest likely to be associated
with wood packaging material in international trade, all life stages of the 7 selected pests should be
exposed to a range of treatment levels commencing with the lowest and culminating in a treatment
level which achieves complete mortality. It should be noted that one treatment level exceeding the
level, at which complete mortality was achieved, should be included in the testing to further confirm
the level at which complete mortality is achieved. However, if information indicates that certain life
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IFQRG 11 (2013) meeting notes on draft ISPM15 treatment criteria
TPFQ_2013_Dec_05
stages are not relevant to the proposed treatment, these may be excluded, provided technical
justification is included with the treatment submission.
For each variable in the test (e.g. dose, concentration, life stage, etc.) a minimum of 5 test units should
be used. In Step 1for insects, the test unit should be the single individual. For fungi or nematodes, the
test unit should be a colonized piece of wood as it is not practical to handle these organisms
individually. Individuals or isolates used for testing should have the quality, vigour and stability
appropriate to naturally occurring organisms. Some organisms, for example fungi and nematodes,
should be tested only in vivo (in wood) unless evidence is provided that in vitro testing (e.g. fungi
grown on nutrient agars in Petri plates) provides equivalent and acceptable results. Reasons for the
selection of isolates should be clearly documented in the submission.
The results of the screening should document the treatment responses among the 7 pests selected for
testing. The screening should also indicate which of the pest life stages tested is the most tolerant (i.e.
the pest life stage requiring the highest treatment level to achieve success).
Step 2: Effect of physical parameters
Step 2 identifies the minimum treatment level which is delivered throughout the profile of the wood
tested under differing physical parameters. Treatment efficacy may be limited by a number of factors
such as:
-
a fumigant may not penetrate larger dimension wood;
-
a fumigant may be diluted by substances in the wood;
-
a treatment may be incapable of killing pests at a particular temperature or moisture content.
Treatment developers should therefore conduct testing of the treatment efficacy under differing
physical parameters which may include:
-
Temperature of the wood and the ambient air;
-
Moisture inside and at the surface of the wood (e.g. wood moisture contents of freshly cut and
dried wood);
-
Dimensions of wood (e.g. sizes of wood used for pallets, boxes or dunnage);
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International Plant Protection Convention
IFQRG 11 (2013) meeting notes on draft ISPM15 treatment criteria
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TPFQ_2013_Dec_05
Anatomy and density of wood (e.g. ring porous, diffuse porous, coniferous, non-coniferous,
sapwood, heart-wood, etc.);
-
Wood species (e.g. tropical and temperate; coniferous and broadleaf);
-
Presence or absence of bark.
A submission should demonstrate that the treatment is capable of killing, inactivating, removing,
devitalizing, or rendering infertile pests (vectors?) throughout the profile of the wood considering
various physical parameters. This may be achieved by monitoring pest mortality or demonstrating that
the effective treatment level can be delivered throughout the entire profile of the wood.
If available information indicates that certain physical parameters are not relevant and were excluded
from testing, the treatment developer should describe the circumstances under which these do not
affect the treatment.
Step 3 – Validation of the effective treatment level
Step 3 validates the efficacy of the effective treatment level identified in step 1 and 2 for the most
tolerant pest life stage. Statistical reliability of 0.95 at 95% confidence level is achieved by exposing a
minimum of 60 test units to this effective treatment level under laboratory conditions (with no
survivors). In Step 3 a test unit is … An effective treatment level may be considered validated under
laboratory conditions when there are no survivors in any of the test units. Consider reordering steps 2
and 3.
Step 4 – Validation under operational conditions
Step 4 validates the effective treatment level under suggested operational conditions by exposing the
most tolerant pest life stage in pieces of wood of a size and nature normally used for wood packaging
material to the effective treatment level identified in previous steps under suggested scale for
operational conditions to ensure that the treatment is delivered to all test units.
Operational conditions used during the testing ?may? indicate the parameters under which the
treatment would be applied once approved. (move to step ‘physical parameters’)
If the most tolerant pest identified in step 1 is Heterobasidion spp. or Bursaphelenchus xylophilus, a
minimum of 60 test units of infested wood should be treated (a single test or 60 repetitions?).
Treatment success for all test units confirms that the treatment level tested is effective at a statistical
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IFQRG 11 (2013) meeting notes on draft ISPM15 treatment criteria
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reliability of 0.95 at a 95% (clarify) confidence level. (Test unit – an infested piece of wood. At least
60 test units.) 1 or more strains to be tested?
If the most tolerant pest identified in step 1 is an insect, the minimum number of individuals for testing
should be determined by considering the biology of the pest, the pest relationship with wood
packaging material and the international trading patterns. Treatment developers should use the
following formula to determine the minimum number of individuals for testing:
I×N×V×3
Number of Insects =
MPL
where:
-
‘I’ is the maximum proportion of units of wood packaging material that are likely to be infested
with a pest (a number between 0 and 1);
-
‘N’ is the average number of individual pests likely to infest a single unit of wood packaging
material
-
‘V’ is an estimate of the highest volume of wood packaging material which has moved in trade to
a single destination (Reference?). Estimated at 300 wood packaging material units; (check with
Mike) Is it constant?
-
‘3’ is the multiplier used to determine the number of test units required to verify a treatment’s
efficacy at 0.95 at the 95% level of confidence (Couey & Chew 1986);
-
‘MPL’ (the maximum pest limit) is the estimated minimum number of pests in wood packaging
material imported during a specified time to a specified location required to establish a
reproducing population.
The number of insects used for testing should not be less than 60.
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International Plant Protection Convention