Re: CP digest 580
Andrew Marshall (andrewm@eskimo.com)
Thu, 4 Jan 1996 12:39:25 -0800 (PST)
Hi folks,
To add my two cents woth in the discusion re. the best plants for
fungus gnat control I have to say that it is also my experiance that the
Mexican Pinguicula are by far the best at capturing the adult gnats that
are in my greenhouse. P. moranensis, P. agnata and the hybrid P. agnata
x P. gypsicola are the three best and are often times covered with
gnats. Usually in the early Autumn when the ambient humidity increases.
By now there are not enough left to notice except for the occasional gnat
that rises off of a plant pot. I do not notice any being caught by the
numerous species of Drosera I have in there.
To add also, I use the various fork-leaved Drosera outside as
companion plants among the Sarracenia. The purpose to control the adult
crane flies whose larvae are very destructive to roots and rhyzomes.
They are very good at it. I used to use Drosophyllum for this but have
lost the plants I had and damping off has taken the seedlings I had.
I know of no plant that controls the larval stages of either of
these pests but if the adult populations are kept to a minimum then
damage is rarely a problem. If all else fails then the Gardens Alive
company sells "gnatrol", a form of bt especially formulated for fungus
gnats that REALLY works if the directions are followed. I don't have an
address on hand for them at the moment but if I can find it I will post
it. It is the only organic larvacide I know of for these pests.
Meanwhile, I hope everybodies holidays were happy and that
everybody has a happy and prosperous new year.
Good Growing
Andrew