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Almond Facts
JANUARY | FEBRUARY 2017
Proven techniques and new approaches to
controlling one of the most destructive pests
targeting almonds were presented at the
Blue
Diamond
annual growers meeting in Modesto
in November. Jhalendra Rijal, Area IPM Farm
Advisor for San Joaquin, Stanislaus and Merced
counties, discussed techniques and materials that
the University of California Cooperative Extension
is using for monitoring and management of the
navel orangeworm (NOW).
Describing the life cycle and best times and materials for
treatment to prevent economic damage by NOW, Rijal
described the insect as a small moth that lays clusters of
tiny white eggs on the nuts. When it is time for the eggs to
hatch their color changes to orange. Tiny larvae emerge
and begin feeding on the nuts. They continue to do so
until they pupate and eventually emerge as a moth.
NOW overwinters as miniature larvae. In March/April,
the surviving larvae pupate and emerge as moths in April
and May and begin laying eggs. “This generation is of
concern because they lay eggs in the mummy nuts, which is
why it is very important to remove the mummy nuts during
post-harvest orchard clean-up,” Rijal counseled. The
moths that emerge from the mummy nuts lay eggs on the
developing nuts, producing new generations of NOW to
infest the crop. Rijal found high counts of third generation
moths in Merced-area orchards as late as October 21 and
speculates that a fourth generation could have emerged in
orchards south of there in years of high temperatures.
Monitoring
Egg Trap
The IPM team uses egg traps, pheromone traps and
harvest samples to develop data for estimating NOW
Update on
NOW Control
Fresh insights on monitoring
and treatment
