May 2019 WCN Digital Edition

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applications. Replace the traps when
the surface is contaminated with flies
or debris and replace the lures at the
interval recommended by the manufacturer.
If you make your own lures
replace them once a week. Monitor
the traps twice per week until the first
insecticide application. Immediately
after the first application replace the
traps and lures and begin monitoring
on a weekly schedule for the remaineder
of the season. Trap captures will provide
a measure of the effectiveness of the
insecticide application and signal when
the next application is required.
"
An application at two weeks
following fly captures should
prevent damage.
Timing of Control
Timing of the insecticide application
in large measure depends on the
method of control. If a standard speed
sprayer is used, the first application
should be applied about two weeks
after the first flies are captured on the
traps. WHF oviposition takes place
two to three weeks after female WHF
emergence. An application at two
weeks following fly captures should
prevent damage. Subsequent applications
should be made when fly capture
rebounds, and again, at two weeks
following fly resurgence as indicated
by trap captures. Under
high WHF population,
four to eight
applications at two to
three-week intervals
may be required to
prevent damage. Control
may begin in early to
mid-June and should
"
Walnut husk fly maggot.
continue until the beginning of husk
split. If GF-120 is used with an ATV
and modified weed sprayer, then applications
should start the week following
the first fly captures and continue on a
weekly basis as long as flies are captured.
GF-120 sprays should be directed as
high in the tree canopy as possible. A
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West Coast Nut May 2019