I have never personally seen a live Achatinella on a tree, but have read
many articles in HSN and IHSN on the subject.  They are very restricted
in their movements.  This has resulted in snails on individual trees
being one species or subspecies, and in there being a lot of
species/subspecies, though the number is severely reduced at present and
they are on the endangered species list (except for one extinct
species).

The genera are very specialized on what trees they can live on, and only
exist on those tree species.  In captivity, they must have leaves from
the proper trees.

I don't recall how they manage to spread, but it isn't very efficient.
--
                     Aloha from Wesley M. Thorsson
Editor of Internet Hawaiian Shell News, a monthly Internet Publication
           122 Waialeale St, Honolulu, HI  96825-2020,  U.S.A
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