Sciara infestations on Arabidopsis - help!

[Dr. Andrew P. Lucy CBiol. MIBiol. Ph.D.]

Hey!  A new guy to the newsgroup and a pathologist at that.  So, forgive
me for killing your weeds!  My question actually relates to something
else killing mine!  We have a bit of an infestation with Sciara flies
(fungus gnats and root maggots).  Has anyone got some advice on a good
way of killing them off without killing my plants?

Cheers!