Plausible biogeographic scenarios.

[Ingolf Askevold]

Dear netters:

     I've written a paper about the biogeographic significance of
the discovery/ocurrence of a species of donaciine leaf beetle
(Donacia) in Costa Rica and Honduras.  The group as a whole is
rather temperate, and the species in question otherwise occurs
widely in souteastern U.S.A.  The group (subgenus) this species
belongs to uses Nymphaeaceae (mainly Nuphar and Nymphaea) as host
plants.  The larvae live attached to the roots/rhizome.

     The reviewers of the paper have suggested two things to
explain this disjunct distribution, contrasting my own
postulations:
     1) That humans transplanted the pond lilies, with beetles as
accidental tourists.  My reply: Well, that means they'd have to dig
up roots and all.  Now, why would people bother doing this?  These
plants are already indigenous to that region.  Assuming they dug up
the plants, it's likely that additional species would also have
been transported, not just the one.  Just doesn't seem likely, it
seems to me.  What do botanists have to say about this sort of
idea?  These beetles are not leaf-mining or stem-boring, and it's
just not probable that they'd have been transported in this way.
     2) That the beetles, because they're attracted to lights, flew
out to ships and latched on, then were transported as accidental
tourists to Costa Rica and Honduras, and subsequently became
naturalized.  Yeah, sure.  I've got some swamp in Florida for these
guys...  My reply: just how much more ad hoc can they be and still
be more credible than the postulations I made?  There's simply no
evidence to support this sort idea.

     Anyway, I have to reply to this sort of old school stuff,
because the reviewers and therefore also the Editor believe the
paper is seriously flawed unless I address these issues fully and
give them fair consideration.  Sigh.

     I would appreciate a little input from fellow modern
systematists, including botanical types.  I would appreciate
responses from some of you, commenting on these "criticisms" and
"alternative explanations", which I would like to download and add
to my response to the Editor.  Credit will be given to you, of
course.

     Please, respond to me directly:
     Ingolf S. Askevold
     iaskevol at vm.cc.famu.edu