COVERSTORY
by Eric Hopper
Organic Control’s (Orcon) Nematodes for
Pesticide Free Fungus Gnat Control
F
ungus gnats are arguably one of the most an-
noying pest insects in an indoor garden or
greenhouse. One reason they are so annoying
is because fungus gnats are extremely diffi cult
for a gardener to eradicate. Fungus gnats look like
small fl ies and they infest soils, potting mixes, and hy-
droponic media. Essentially, they can live anywhere a
plant grows roots or where there is decaying organic
matter. The larvae of fungus gnats primarily feed on
fungi and other organic matter in the soil, but they
can also damage roots.
Fungus gnats develop through four stages: egg,
larva (with four larval stages), pupa and adult. The
females lay their eggs in damp, organic media. At 75
degrees F, the eggs will hatch in three days; the lar-
vae take about ten days to develop into pupae, and
about four days after that the adults emerge. An entire
generation of fungus gnats can be brought forth in
approximately 17 days, depending on environmental
conditions. The warmer it is, the faster they develop;
6
resulting in more and more generations emerging.
Fungus gnats have many overlapping generations per
year. They can be found at any time of the year in
coastal regions or in indoor gardens and greenhouses.
Gardeners who have experience with indoor horti-
culture know that plants grown indoors in potting
containers are particularly susceptible to fungus gnat
issues.
Finding a Treatment
There are many different treatments and control
methods for fungus gnats. Unfortunately, many of
the harsh chemical treatments can actually be coun-
terproductive because they damage the integrity of
the soil and/or the plants themselves. Systemic treat-
ments and root drench products made for ornamental
plants should never be used on vegetable or other
consumable plants. Indoor gardeners and greenhouse
growers who like to grow their own food or medicine
should turn to more natural approaches when treating
www.GardenandGreenhouse.net
May 2018