ANNUAL GROWERS MEETING
Mating Disruption for NOW
A proven technology that achieves upwards of a 50
percent reduction in Navel Orange Worm (NOW) damage
in almonds drew a large audience for the Emerging
Technology Forum: Pheromone Mating Disruption for NOW
at the
Blue Diamond Growers
annual members meeting.
Comments by Mel Machado,
Blue Diamond’s
director
of member relations, set the stage for the discussion by
explaining the attraction: “2017 was a very bad year
for Navel Orange Worm rejects, one of the worst ever.
Growers lost hundreds of dollars per acre to the pest.
While 2018 is better by nearly half, depending on region
and variety, growers are still losing a lot of money to
NOW.”
Even an apparently good score on rejects can mask the
damage, he continued. “If your reject report shows two
percent you really had a four percent reject level because
half of the rejects were eliminated by the harvester and huller
equipment. Your dollar loss was far greater than you think.”
Declining Control Options
While NOW damage declined for the 2018 crop,
Machado warned, “The improvement may be short-lived.
The environment in which we operate is changing. There
are some 2.5 million acres of habitat – almonds – for
NOW. We are seeing a greater accumulation of heat
which NOW enjoys. There’s greater variability in rainfall
which can affect orchard operations such as mummy
removal.”
Also, declining options for NOW control are a major
concern. “We have limited chemistry to choose from,” said
Machado. “We have lost most of the better materials.
What we have left are softer and less effective. So, we
have to think out of the box and explore new measures, like
the cotton industry did in eradicating the pink boll worm by
developing and releasing sterile insects.”
Machado explained that the sterile insect technology might
have too many technical hurdles for application to NOW.
However, other technologies can be added to an almond
grower’s arsenal of tools, chief among them, a proven,
effective technology widely used in other crops and
applications around the world but new to almonds: mating
disruption (MD).
Mating Disruption Works
Bradley Higbee, a leading innovator and researcher of
mating disruption technology for NOW at USDA before
joining Trece, Inc. as a field research and development
manager, explained how it works and its proven
effectiveness. “MD technologies interfere with the ability
of males and females to find each other to mate,” he said.
“The NOW female emits a sex hormone that forms a scent
plume that the males detect and follow back to her to mate.
Isolating the components of that scent and developing
synthetic versions involves complex chemistry, but we have
been successful in developing compounds that are effective.”
According to Higbee, MD products come in three types:
deactivator, a central nervous system interrupter that
interferes with the male sexual impulse; camouflage, where
multiple scents confuse the male; and competitive attraction,
which releases false attractants that send males chasing
multiple plumes to no avail.
Higbee noted that the products in use in almond orchards
today rely on one or more of these mechanisms, depending
on the formulation and how they are dispensed. The
materials are either sprayed on for targeted applications,
released through dispensers hung in the trees or emitted
from “puffer” aerosols that respond to temperatures and
timers to release a precise amount at a precise time for
maximum effect.
The first MD materials were approved by EPA in 1978.
Over 200 products are registered in the U.S. to date. Most
From left to right: Mel Machado, Kent Stenderup, Jeremy Siebert,
and Bradley Higbee
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A L M O N D F A C T S
