tg_efficacy_pt18pt19_superseded_en

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Transitional Guidance on PT18 + PT19
September 2016
d) assess if a contaminated group of termites can transfer the insecticide to a group
of termites that have never been exposed to it before. This transfer study should
demonstrate acceptable toxicity of termites not exposed directly to the baits.
5.2.2.1 Laboratory/screening tests
No-choice test (A): test the termiticidal efficacy and the delayed effect of an insecticide
formulation on a group of subterranean termites”:
A group of termites is put into contact with an insecticide formulation. When testing
baits, bait is the only source of food. For other types of termiticides the termites are
exposed to the product according to the intended use (e.g. spray the surface and add
the termites to the surface. The test is performed in assay containers. Mortality of the
insects is assessed.
From this test the time “te” can be determined, necessary to perform the test B
(te=time of exposure of the termites to the insecticide formulation which is required to
observe a significant mortality compared with termites in an untreated control).
Transfer test (B): the transmission of the insecticide used in the baiting system to an
uninfected group of termites:
Termites are exposed to the tested bait long enough to be contaminated with the active
substance (time te). A group of termites is removed from the colony and put in contact
with a healthy uncontaminated group. The mortality rate of both groups of termites
(contaminated and uncontaminated) is assessed separately.
Choice test / palatability test (C): the suppression of a group of termites reared in
laboratory under conditions of food competition; with the use of the same insecticidal
bait formulation:
Add the insecticidal bait formulation to a group of termites already exploiting another
source of food. The test is performed in assay containers. The aim is to assess the
mortality after a given period of time.
5.2.2.2 Field trial
In field trials the product is tested in actual use situation and applied according to the
direction for use on the label. The test method should evaluate the efficacy of the baits
or barrier products in an experimental site where termite activity is reported.
The repellent termite barriers can be disposed in walls or soils, according to the claim. A
common claim for a barrier product is the duration of “protection”. This is normally in
terms of a number of years and should be demonstrated by long-duration soil tests in
field plots.
For bait products consumption of the tested bait must be registered at least in the first 6
months after the introduction of the baits. The elimination of termites in the
experimental site should be registered maximum after 18 months (counted since the
introduction of the first tested bait), excluding the winter period.
Table 2 gives an overview of available (French) guidelines for termites and how to use
them.