Double mounting with polyporous fungus blocks

Nick Greatorex-Davies ngd at
Thu Apr 13 06:29:15 EDT 2000

I still use Polyporus strips (Piptoporus [=Polyporus] betulinus) for all lthe smaller microleps I mount as I have not run out of stocks I bought years ago. It was available in the UK from Watkins and Doncaster (The Naturalists), P.O.Box 5, Cranbrook, Kent, UK  TN18 5EZ, 

I have prepared my own in the distant past with some success from P. betulinus collected from dead or dying Birch (Betula pendula) in September and October. I was told at the time that it has to be carefully prepared by washing a chemical out of the fungus. This is done by squeezing it (like a sponge) repeatedly in clean water. If this is not done, I was told, it  would go rock hard when it dried. (I have since been told by Watkins and Doncaster that this is not necessary!) The 'Polyporus' then needs to be sliced and spread out to dry. It can then be cut up as required, though the outer layer of the slices which is most exposed to the air goes hard.

Watkins and Doncaster now sell a Polyporus substitute called Nu Poly, which is a dense white foam but denser than Plastozote. They supply it to the Natural History Museum in London. It costs (UK money) £1.45 per box - don't know how much is in a box. Sounds a lot better option than preparing your own Polyporus.

Nick Greatorex-Davies

Mr J Nick Greatorex-Davies
(Butterfly Monitoring Scheme co-ordinator)
NERC Centre for Ecology and Hydrology
Monks Wood
Abbots Ripton
Cambridgeshire PE28 2LS  UK

Tel: (+44) (0) 1487 773 381
Fax: (+44) (0) 1487 773 467
E-mail: ngd at

>>> Charles Bird <cbird at> 11/04/00 15:53:02 >>>
A number of sources advocate double mounting micro moths with polyporous
fungus blocks (eg. Covell, Eastern Moths, p 21). More recently, Landry &
Landry, J. Lep Soc. 48:222 state, "Traditionally, blocks have been cut from
strips of polypore fungi (especially from birch bracket fungus). Normally
it is easy to procure polypore strips from naturalist supply houses, but
periodically they tend to become very difficult to obtain."

I recently tried cutting strips from freshly collected specimens of Fomes
fomentarius [Tinder Conk] from birch and from Phellinus tremulae (Fomes
igniarius) [False Tinder Conk] from trembling aspen but found both to be
too hard. Perhaps these are the wrong species or I should have collected
them at another time of the year. Ideas anyone?

Landry & Landry (p. 223) recommend against using blocks made from balsa,
cork, and polystyrene foam (styrofoam) as they are either too hard or are
not rubbery enough to firmly hold a minuten pin. They further state that
the durability of blocks made from a silicon rubber compound is uncertain.
Schauff, Collecting and Preserving Insects and Mites (p. 32), however,
appears to feel that silicone rubber blocks are OK.

I notice that the latest Bioquip catalog (p. 33) lists only inert silicon
rubber and plastazote double mount strips. Is there still a source of
supply for polyporous fungus blocks?

It would appear from the above that polyporous blocks are the traditional
favorite but that plastazote blocks may be the current favorite. Your views
would be appreciated.


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