BS EN 47:2016 pdf free.Wood preservatives – Determination of the toxic values against larvae of Hylotrupes bajulus (Linnaeus)一(Laboratory method).
BS EN 47 The larvae shall preferably be obtained from cultures reared according to the method described in Annex B.
Otherwise larvae in Category 2 can be taken from naturally infested wood, in which case they should be transferred into sapwood of pine and stored for at least 4 weeks under the rearing conditions specified in Annex B.
Do not use the larvae in the test if they have not fed normally during this storage period.
Collect larvae in Category 1 from eggs bid by different females.
Carefully cut out the larvae in Category 2 from the culture blocks and keep them separated from one another for 2 days to 3 days in the culturing chamber (5.3.1) to check that they are healthy.
Use only healthy larvae in the test.
NOTE A healthy larva can be recognized by its ivory-white colour. its firm consistency and rounded appearance, and by the absence of wounds or bites which show up as dark marks. Healthy larvae react to the touch by vigorous movement and attempts to bite.
Reject any larvae which are shrunken or aged, which have recently moulted, or which are in a pre-pupal stage.
The number of larvae per treated and control test specimen shall be six of Category 1 or one of Category
Sort the larvae retained in Category 2 mentioned above.Do not use larvae weighing more than 150 mg as they may pupate and therefore interfere with the test. For a single test, use a mixed batch of larvae of Category I and for Category 2. as far as possible, use larvae of similar masses. The number of larvae necessary Is given in Table 1.
Drying vessel(s), capable of holding sets of five test specimens (7.5), provided with a closefitting cover and containing supports that will give minimum contact with treated test specimens to be placed on them. The vessels and supports shall be of a material that does not react with the preservative under test, for example glass for organic compounds and polyethylene for products containing fluorine.
Drill and twist drills, approximately 3,0 mm to 4,5 mm in diameter, and a fine awl. In all cases,the number of bits shall be sufficient to drill holes to the size of the larvae available; in the case of larvae of Category 1, use a steel awl. BS EN 47 pdf download.