Spraying for Spotted Wing
Drosophila in Highbush Blueberry
Dr. Jason S.T. Deveau
Application Technology Specialist
OMAFRA, Simcoe Station
Automated, flying field sprayer from the movie “Looper” (2012)
A brief history of SWD in N. America
2008:
Detected in California
2009-10:
Spread up the west coast to British Columbia
2010:
Invaded south-east coast
2011:
Spread up the east coast
End of 2011:
Found in 60% of monitoring traps in Ontario
2012:
Pretty much everywhere… 
Traps
• Traps placed in shade in plant canopy, or
securely on the ground, or near wild hosts
• Traps checked and bait changed weekly
• Minimum 2 traps per site when fruit forms
Wire
hanger
500 millilitre deli cup
containing apple cider
vinegar, red wine and
soap (or 1 Tbsp. active
dry yeast: 4 Tbsp. sugar:
12 oz water)
3 millimetre
holes (lots of
them)
Red duct tape
(they like red
or black)
Damage
• You’ve all seen the damage SWD can wreak –
it’s significant
Photo Credit: V. Walton,
Oregon State University
Cultural control
• Remove / destroy all overripe, infested or
dropped berries. Bury >12 inches - no
composting
• Bag cull berries in garbage bags or solarize cull
piles with tightly sealed polyethylene for at least
a week (may not be feasible)
• Harvest berries early, clean and frequently
• Monitor SWD activity and know where there are
alternative host plants. Removal might be
warranted (may not be feasible)
• Prune bushes to allow for better spray coverage
Chemical control
• Right now, there’s no IPM action threshold based
on trap counts
• But, entomologists know females are attracted to
ripening fruit
• So:
Insecticide choice
Insecticide choice
• The USA has more choice than
Canada. Rotate your groups!
Resistance is a serious concern
Spray timing
• The target is adult fruit flies, not eggs (although
possibly with neo-nics), and the generations
overlap. Spraying before you know there’s a risk
wipes out beneficials
• Please, be mindful of
bee activity. Spray in
the evening (as long
as there are no signs
of a significant
temperature
inversion)
Spray intervals
• Most of these products have a ~7 day residual,
but that’s weather-dependent
• Calendar spraying is not recommended. Base
the first spray on adults trapped in the region
concomitant with ripening fruit
• This could mean many more applications than
you’re used to… hard on U-pick operations…
Where is the pest?
• Wild host plants (e.g. wild brambles, chokecherry,
dogwood… almost anything with berries)
• Cull piles
• In the lower regions of highbush blueberry because they
prefer moderate temperature, shade and humidity
Photo Credit: R. Issacs, Michigan State University
How to spray the lower region
Gary VanEe
Richard Ledebuhr
Eric Hanson
Jim Hancock
Donald C. Ramsdell
HortTechnology
April/June 2000
pp. 353-359
Three application methods
• Airblast, Alternate Row Middle Application
187 L/ha (20 US g/ac)
5.5 kph (3.4 mph)
3.2 ha/hr (7.9 ac/hr)
Three application methods
• Airblast, Every Row Application
187 L/ha (20 US g/ac)
5.5 kph (3.4 mph)
1.6 ha/hr (4.0 ac/hr)
Three application methods
• Sardi-style, sprayed four rows at a time
using ½ the volume per planted area
compared to airblast
94 L/ha (10 US g/ac)
5.5 kph (3.4 mph)
6.7 ha/hr (16.5 ac/hr)
Diagnosed coverage
• Water-sensitive papers were used in four
quadrants to monitor coverage
Compared pruning
Results – pruning and method
(Data avg. from four sprays - pink-bud to green fruit)
Results – growth stage and method
Are booms viable options?
• Boom typically has no air assist
• Boom reduces trample (i.e. knocking berries off)
• Boom covers a lot of area quickly
• Based on VanEe et al. and experience with spray
wands, my guess is that booms may not work
• Aerial application, however, might (Rufus Issacs,
Michigan State University, is exploring this)
Beware blanket statements
…even mine
• Penn State extension recommends adding a stickerspreader and using higher-than-normal volumes to
improve coverage
• Are either appropriate?
Adjuvants
From Dr. H. Zhu, Ohio State USDA
• Adjuvants are a case-by-case issue
• They can help...
Adjuvants
• …or they can
harm
• Test them
locally before
applying
generally
• Add sugar to
the spray tank?
Richard Cowles,
University of
Connecticut
says yes
Volume depends on method and crop
(Jerseys planted 1979,
sprayed in late June)
•
Use the papers
and aim for ~20%
coverage and
~85 drops / cm2
in hard-to-reach
places
Too much air and volume is wasteful
Nozzles and volume
• Turn off nozzles and adjust deflectors (if present)
to just over- and under-shoot the canopy.
Nozzles and volume
• One setting
for your
sprayer will
not suffice
for the whole
season
• It may not
suffice for
significantly
different
blocks,
either
Know your nozzles
Know your nozzles
600 L/ha (~ 65 US g/ac)
<400 L/ha (~ 42 US g/ac) using Venturi nozzles
The importance of air
The importance of air
Air direction
• Air carries spray – watch where it goes
• Park in an alley
and compare the
ribbons to your
canopy
• Adjust deflectors
to channel air into
the canopy
• More than one
crop? Then you
may need more
than one setting
Use short lengths of bright ribbon. Mind they don’t
snap or get sucked into the air intake!
Air speed
Dr. Bernard Panneton, Ag Canada, QC
• Using LiDAR in
apples, Bernard
found more surface
area was exposed
when using just
enough air to rustle
leaves versus no
air at all
• He also found that
too much air (too
fast, really) reduced
surface area versus
no air at all
Air speed
• Who says 540 rpm’s is the
only way to go? As long as
your tractor doesn’t lug,
and you’re using a
positive-displacement
pump, you can try this
Overall sprayer setup
Overall sprayer setup
Take home
• Pruning increases spray penetration and
improves coverage – especially when
you aim the spray at the trouble spot
• Neither overhead boom nor alternate
row-middle spraying are recommended
for control of SWD in highbush blueberry
• Use water-sensitive paper to confirm
~20% coverage. That and ribbons are
your guide to travel speed, volume and
air settings, which must change as the
growing season progresses and between
significantly different plantings
Online SWD resources
THANKS!
Based on G. Pryor, 2003
Dr. Jason S.T. Deveau
Application Technology Specialist
OMAFRA, Simcoe Station