Lygus Control, New
Chemistry & Crop Loss
Reporting
Lygus Management
• Review of status of Lygus IPM
– What do we know & need to know?
•
Ask and answer (?) two questions
• Review chemical control
Peter C. Ellsworth
IPM Specialist
Maricopa Agricultural Center
University of Arizona
• Introduce new chemistry
– Selective options for Lygus control?
– Big impact?
• Crop Loss Reporting
– Insecticide use trends, historical review
Desert Ag Conference
12 May 2004
– Focus of breakout in afternoon
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Lygus IPM…
…depends on 3 basic keys
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Key Elements…
…what have we got?
3
2
1
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Lygus Can Be Managed Better!
Lygus Can Be Managed!
Even side-by-side
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1
Spray all
you want!
Lygus
hesperus
Adult
• Can cause
damage
• Cannot be
reliably
controlled
• Key to
movement &
reproduction
Two Scales for Questions in
Lygus Management
• When should managers discontinue any
further Lygus chemical controls in cotton?
• Can we estimate & characterize inter-crop
effects of Lygus spatially?
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Extension
Program
• Initiated in 2000 in
response to extreme
and negative
interactions among
producers of different
crops
• Communication /
Awareness
• Education
• Systematic Survey /
Research
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Spatial Study
• Two townships, spring &
early summer hosts (April July)
• Cotton, alfalfa, seed alfalfa,
fallow, weeds, and small
grains; georeferenced
• Sweeps (15 in. diam.) from
each potential host weekly
• Examine source / sink
relationships among crops
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Ring Analyses to Determine
Range of Impact of Lygus
Ring Analysis?
• Around each focal cotton fields,
calculate crop densities in
concentric rings
C
Tree Rings?
• Multiply that crop density by the
mean density of Lygus in each ring
= Estimate of source potential
Crop Circles?
• How are Lygus densities in focal
fields related to source potential of
surrounding crops?
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Ellsworth/UA
2
Focal Cotton Fields (50)
Spring Lygus Densities
(adults & nymphs)
Focal cotton field
Seed alfalfa
Forage alfalfa
Cotton
Fallow
• Significantly more Lygus were found in Seed
Alfalfa, Forage Alfalfa, and fallow fields (weeds),
than in cotton
9
Lygus Density
(log D + 1)*
1.50a
34
1.45a
Fallow
3
1.44a
Cotton
72
0.69b
Crop Type
N
0.75 km
Seed Alfalfa
Forage Alfalfa
* Values fb same letter not significantly different (P > 0.05)
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Strategic Planting
Lygus Associations
Sensitive host
• Seed alfalfa fields are
sources of Lygus for cotton
fields. This effect does not
extend beyond 1 mile.
Non host
ile
1m
Source
• Cotton fields are sinks for
Lygus. This effect
disappears beyond 0.5 miles.
• Strategic placement of crops
could help alleviate Lygus
problems.
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Adults move; Nymphs don’t
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Adults move; Nymphs eat!
UTC
00F3threshold
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3
Avoid Adults; Control Nymphs!
3 Sprays
0 Sprays
Note height difference
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Sampling & Thresholds
Yield & Revenue : Density
104 87
60
53
35
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100 sweeps
0 <== ave. costs
1.5
R2 = 0.86
1
• Maximum Yield @
1.7 nymphs / 100
0.5
• Maximum Revenue
@ 5.2 nymphs / 100
0
-0.5
-1
• Recommendation:
4 nymphs with at
least 15 total Lygus
-2.5
per 100 sweeps
-5
0
5
10
15
20 25
30 35
(‘15:4’)
Threshold (in nymphs / 100; 15T)
-1.5
-2
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Sampling & Thresholds
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Sampling & Thresholds
13 Adults
+
4 Nymphs
(17:4)
13 Adults
+
3 Nymphs
(16:3)
is over
is under
‘15:4’
‘15:4’
Spray
Not Yet!
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4
Two Scales for Questions in
Lygus Management
• When should managers discontinue any
further Lygus chemical controls in cotton?
Timing Late Season Controls
(when should you stop spraying?)
Lygus
Termination
(LT)
16-Aug
5-Aug
Spray Dates
23-Aug
6-Sep
2 wk < c.o.
20-Sep
1 wk < c.o. 1 wk > c.o.
3 wk > c.o.
LT4
LT3
• Can we estimate & characterize inter-crop
effects of Lygus spatially?
– Seed alfalfa can be a source for Lygus in cotton
LT2
LT1
– Lygus can apparently move from a source and
affect fields up to 1 mile away
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c.o. = cut-out or nodes above white flower = 5
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Every Year is Different!
Large Yield Difference
LT1 << LT2
2.5
2
1.5
1
0.5
0
4 5
23
DP422BR
early
You should
have quit
while you
were ahead!
Lygus Sprays
LT1 LT2 LT3 LT4 LT1 LT2 LT3 LT4 LT1 LT2 LT3
LT4
02F4LT
L
T 3 weeks > cutout,
4 5 sprays, 9/20/02
L
T 1 week > cutout,
3 4 sprays, 9/6/02
4 5
4 5
23
23
DP33B
medium
L
T 1 week < cutout,
2 3 sprays, 8/23/02
L
T 2 weeks < cutout,
1 2 sprays, 8/16/02
DP655BR
full
Lygus Chemical Termination X Variety
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Ellsworth/UA
2003 Experiment
3
4
• Two planting dates: April 30 & May 28
0
a a a a
• Three varieties: SG215BR, DP449BR, DP555BR
0
a a
a
0
0
a a a
b bb
3.5
3
a a a a
b
a
a
b
0
a a
b
c c
a a a
b b
c c
bbb
c c
4
4
3
2
2
2
2
1
0
0
0
2
1
1
1
1
1
3
3
2
2
1
4
4
3
3
3
3
3
4
4
4
4
3
2
1
1
1
a a
a a
bb
a
b b
c c
0
0
0
0
a
bb
c
bb b
c c
2.5
2
1.5
• Two irrigation termination timings: Aug. & Sept.
1
0.5
• Four Lygus chemical control terminations
0
High heat stress & fruit shed July-August
0
1
4
3
0
3
3
2
1
2
2
4
Opt Opt Opt Opt Opt Opt Late Late Late Late Late Late
215 215 449 449 555 555 215 215 449 449 555 555
Late Opt Late Opt Late Opt Late Opt Late Opt Late Opt
Extremely productive “fall”, long, open and dry
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5
High Populations Late
Season
a a a a
a a a a
a a a a
a a a a
a a
a a a
bbb
a a a
b
a
b
Nymphs / 100 s
50
45
40
35
30
25
20
15
10
5
0
Yield : Nymphs Relationship
4
bb
c
3.5
3
2.5
2
1.5
Opt Opt Opt Opt Opt Opt Late Late Late Late Late Late
215 215 449 449 555 555 215 215 449 449 555 555
Late Opt Late Opt Late Opt Late Opt Late Opt Late Opt
a a
a
b b b
100
36
30
24
18
12
0.5
0
6
Opt Opt Opt Opt Opt Opt Late Late Late Late Late Late
215 215 449 449 555 555 215 215 449 449 555 555
Late Opt Late Opt Late Opt Late Opt Late Opt Late Opt
a a a a
a a a
bb
a a a a
a a
b
a
bb
a a a
b
a a a a
a a a
b b
Effective & Selective
Chemistry
a a a
bb b
0
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50¢ Cotton Returns
150
42
1
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200
48
a
b bb
a a a a
b b b
c c
Don’t Spray
• Effective chemistry is
available, but limited to
broad spectrum materials
(I.e., Orthene or Vydate)
50
0
-50
-100
3
Sprays
2
0
1 Spray
0
Opt Opt Opt Opt Opt Opt Late Late Late Late Late Late
215 215 449 449 555 555 215 215 449 449 555 555
Late Opt Late Opt Late Opt Late Opt Late Opt Late Opt
• Selective technologies have
been key to managing
whiteflies and pink bollworm
• Can selective agents be
found for Lygus?
Ellsworth/UA
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Studies Identified Effective Compounds
2002 Lygus Screening Trial (02F4L)
(5-fold increase in yield)
Large nymphs per 100 sweeps (seasonal ave.)
30
5-fold Increase in Yields (98 F4W)
Orthene 90S
Orthene 97
Vydate CLV
Regent
Program (3X)
Must & Thio
Lann & Thio
Thiodan 3E
Legend
C293343-H
C293343-L
UTC
25
a
Thionex
Vydate
a
abc
20
Orthene
bc
c
Rotations
15
d
Experimental
d
d
10
Control
de
ef
Lint (bales/A)
0
0.5
1
1.5
2
2.5
5
f
f
0
3
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2 r4
C
x r17
1 x
2 x3 C
4 T
5 V
6 O
7 8 Neonicotinoids
9 10 11 12 13 14 15 16
18
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6
Adults Unaffected (02F4L)
2002 Lygus Screening Trial (02F4L)
Yield in bales per acre
Adults per 100 sweeps (seasonal ave.)
1.4
60
1.2
50
1
40
0.8
30
0.6
20
0.4
10
0.2
0
0
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Cx x C T VO
Neonicotinoids
x r2 r4
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> 10-fold Increase in Yields (02F4L)
Selective Chemistry?
Yield in bales per acre
1.4
1.2
1
Orthene
0.8
(1.28 bales)
0.6
Control
0.4 bales)
(0.11
Carboxylesterase : tacrine
0.2
0
Cx x C T VO
Neonicotinoids
x r2 r4
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Ellsworth/UA
Yield (03F4Eff)
New Chemistry: Selective
Options for the Future?
*
*
*
*
Flonicamid
(4 Sprays)
• Novaluron (Diamond)
–
–
–
–
–
Makhteshim-Agan
Uniroyal / Crompton
Benzoylurea
Chitin inhibitor
Contact only
Orthene
(5 Sprays)
–
–
–
–
–
Regent
a
• Flonicamid
Vydate
ISK Industries
FMC Corporation
Pyridine carboxamide
Feeding inhibitor
Systemic
b b
b
c
c
(5 Sprays)
d
(5 Sprays)
f
f
g g
g
f
Control
(0 Sprays)
O VCDF RU
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Insecticide Use in AZ Cotton
Lygus Nymph Control,
7DAT (03F4Eff)
70
a
b
c
a
b
a
a
b
a
b
c
60
b
c
d
a
b
c
d
• Selective technologies stabilized usage (i.e., Bt & IGRs)
• However, current usage reflects the importance of Lygus
c
d
d
50
UTC
(0 Sprays)
Diamond
Flonicamid
(1 Spray)
(1 Spray)
40
30
20
10
0
U
0
10
11
12
13
O
14
V
15
D
17
F
18
R
19
Pink bollworm
12
10
8
2
0
Other
$113 (ave. cost / A)
$106
$138
$121
$111 $108
6
4
Lygus bugs
$217
$68
$103
$37
$56
$62
$64
1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002
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Acknowledgments
• Virginia Barkley who supervised and others (7)
who conducted the sampling
• Christa Ellers-Kirk for assistance with analyses
• Larry Antilla, Jerry Kerr and the rest of the
ACRPC staff who provide crop maps &
coordinates
• Steve Husman, Dave Langston, Jennifer Jones
and cooperating growers involved with the
implementation of the Maricopa Community Wide
Lygus Action Plan
• ACGA and Cotton Incorporated who supported
(pce) the Lygus termination studies
• Over the last 5 years…
• 45% of all insecticide sprays have been
targeted at Lygus
• 41% of the entire insecticide budget has
been invested against Lygus
• 66% of the yield loss has been attributed
to Lygus
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• All University of Arizona
crop production & crop
protection information is
available on our web site,
Whitefly
14
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Major Threat to Cotton
Production in AZ
Information
Ave. Foliar Spray Intensity
80
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A
C
I
S
• Arizona Crop Information
Site (ACIS), at
• http://ag.arizona.edu/crops
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