An article in the latest edition of Greenhouse Grower reports research in
using fresh cut potato slices (about one inch across by 1/4 inch thick) to detect
and remove fungus gnat larva from four inch pots of plants. The fresh cut
slices were placed on the soil of pots infected with a known number of lab
raised fungus gnat larva. In 48 hours, 54% of the gnats in an average pot were
found on (or near enough to be easily removed) the potato slice.
While I would not advocate using potato slices as a fungus gnat control on
our Bonsai. (Good watering practices are the best control and an insecticide
drench the next best) I would suggest the potato slice as a diagnostic tool. Do I
have fungus gnats? Try the potato slice. Actually about 12% of the larva
were found on the slice after 24 hours, which would be enough evidence to change
watering practices and maybe treat with a drench. Also carrot slices worked
almost a well as a detector in 24 hours but the potato slices did better after
48 hours in the percentage of gnats removed.

Billy on the Florida Space Coast

************************************************** ******************************
++++Sponsored, in part, by Evergreen Gardenworks++++
************************************************** ******************************
-- The IBC HOME PAGE & FAQ: http://www.internetbonsaiclub.org/ --
+++++ Questions? Help? e-mail +++++