by Bernadell Larson,
HCMG |
MUSHROOMS AS AN INSECT
CONTROL
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Mushrooms and insects
share a close and
ancient relationship.
Last month we discussed
using mushrooms as bio-remediators
and we all know about
the culinary benefits of
mushrooms. This article
will discuss using
mushrooms as an insect
control. |
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The mushroom
TERMITOMYCES is well
known to native peoples
in Africa as a delicious
food source cultivated
by “white ants”, also
known as termites. They
live in its mycelium
where they produce a
honeycomb like structure
from which mushrooms
later grow. There is an
interspecies symbiosis
and the termites are
dependent on these
fungi. Insects, fungi,
and microbes have
coevolved successfully
over great periods of
time without wiping each
other out, and all have
much to teach us. |
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Several big
corporations, such as
Monsanto and Dow, had an
idea to develop
biological controls
using fungal spores to
kill termites and other
insect pests. Their
premise was that fungi
use spores to infect
inspects, which then
become launching pads
for dispensing more
spores. But there was a
problem. The natural
world is excellent at
sensing danger,
communicating about it,
avoiding it, and making
adaptations.
Commercially designed
bait traps house lethal
spores that would kill
insects coming into
contact with them. But,
the insects sense the
danger and instead of
going into the bait
traps, they head the
other way.
Termitomyces medius
with the termite nest in
Ouagodougou, Burkina
Faso*
©JHP |
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A mycologist, Paul
Stamets, needed to rid
his house of carpenter
ants but did not want to
use commercial
pesticides. He started
researching whether
there might be fungi
that are nontoxic to
humans and other mammals
but would target
specific insects such as
carpenter ants. He
became aware of the
ineffectiveness of
commercial applications
of biological control
and felt that the key
was to find the precise
fungal species that has
evolved as a parasite to
a specific insect.
Simply, the mushroom has
developed chemical
compounds that attract
the insect and entice
the insect into eating
the mycelium in its
pre-spore producing
phase. He focused on
species that delay
sporulation (production
of spores). In his
experiment, he put out
about 50 kernels of rice
that contained mycelium
prior to sporulation.
The ants took away all
the kernels of rice and
one week later there
were no carpenter ants
in the house. As it
turns out some fungi,
prior to sporulation,
develop properties
attractive to a specific
insect species. The
fungi entice the insects
to ingest the mycelium
and take some back to
the nest for the rest of
the colony. When
sporulation occurs, the
entire insect colony is
killed. |
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Research has also shown
that beneficial insects,
such as Phorid flies,
can be attracted to
certain mycelia. Phorid
flies are a known
predator of fireants.
Mycelia emit a fragrance
that can attract Phorid
flies from long
distances. Placing the
mycelia close to fire
ant colonies can direct
the Phorid flies to the
colony and the fly will
exterminate the colony.
Termitomyces
reticuloatus with
termite nest
in Ouagadougou, Burkina
Faso*
©JHP |
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There are many more
examples of pairings of
insects and mushrooms
that are being
researched. The Stamets
group has a series of
patent pending
technologies that have
been tested at Texas A &
M University. To date,
the tests have shown
that their techniques
are 100% effective
against Formosan
termites and eastern
subterranean termites,
and 98% effective
against fire ants. In
the future we may have
other choices for
dealing with insect
infestations that allow
us to help keep nature
in balance. |
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* Burkina Faso is a
country in southwest
Africa just south of
Mali and north of Ghana |
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