Sustained Insecticide Performance Against
Whiteflies in Multi-Cropping Systems:
Past Success and New Challenges
J. C. Palumbo, Yuma, AZ
T.J. Dennehy, Tucson, AZ
P.C. Ellsworth, Maricopa, AZ
S.C. Castle USDA, Phoenix, AZ
Sweetpotato Whitefly
Bemisia tabaci – B biotype
Polyphagus
pestand CA,
From• 1991-1993
in AZ
outbreaks
of
whiteflies
• Multivoltine pest caused
> $ 500 million worth of damage
• Adults
very &
mobile
to cotton,
melons
vegetables.
Whitefly “cloud” over newly established produce field
Imperial Valley – Fall 1991
J. Hatch
Shared
Shared
Whiteflies
Whiteflies,
Among
Shared
KeyChemistries
Whitefly Hosts
Spring Melons
Winter Vegetables
Synergized Pyrethoids
Fall Vegetables and Melons
Cotton
Imidacloprid Admire®
Ideal WF Control in Vegetables / Melons
Section 18 Registrations - 1993
• At-plant soil application
• Immediate plant protection
• 45-60 d residual control
Synergized Pyrethroid Resistance in Cotton -1995
•
•
•
•
•
Documented reduction in susceptibility
Reports of poor field performance
Section 18 registrations of IGRs in 1996
1 use of buprofezin and pyroproxyfenin
Cotton IRM Program established
Area-wide Impact
on Bemisia Whitefly
60
50
Admire 1st Used (Section 18)
Admire Field Standard
/ 2leaf
40
Untreated
Widespread use of Admire
30
20
IGRs 1st used in cotton
Nymphs / cm
10
0
93
94
95
96
97
98
99
00
01
02
03
04
05
06
Palumbo, 2006
Sustained Efficacy in
Commercial Broccoli
Sustained Susceptibility
25
Whitefly Nymphs/ cm 2
Untreated
Admire Field Standard
20
95
15
96
97
98
10
99
00
01
5
02
03
0
04
1998
05
Dennehy 2005
1999
2000
2001
2002
2003
2004
2005
2006
Palumbo 2006
Whiteflies have not had a significant economic impact
on the Yield or Quality of vegetables or melons
in Arizona for the past 14 years.
Passive “de facto” Management
Cropping system
•
•
Large acreages of untreated host plants serve as refugia
Alfalfa, seed crops, weeds, ornamental landscape
Whitefly biology and ecology
•
Polyphagy, mating behavior, and dispersal capability
IPM Practices
IPM Practices
•
•
•
Avoid Problems through Cultural Controls
Scouting, Sampling and Detection
Effective Chemical Use
Ellsworth 2001
Effective
Chemical
Use
Passive
“de facto”
Management
Limitation and Segregation of Chemistries
1 soil use of Admire
1 soil use of Admire
1 soil use of Admire
1 foliar use of Buprofezin
1 foliar use of Pyriproxyfen
No Neonicotinoids
used
Kerns & Palumbo 1995
Expansion of the Neonicotinoid Chemistry
Imidacloprid
1) New Product Registrations - 2006
•
•
•
Centric / Platinum:
Intruder / Assail:
cotton, melons
cotton, leafy vegetables
Venom: cotton, melons and leafy vegetables
2) Documented cross-resistance
Thiamethoxam
3) Multiple applications allowed by labels Acetamiprid
Dinotefuran
4) Risk of increased selection pressure
“ We can’t rely on a de facto system anymore “
Proactive Resistance Management
Risk Associated with
Cropping Systems
Central Arizona- Low
Insecticide Usage (Treated Acres, x1000)
Central Arizona- High
400
Buprofezin
Non-Pyrethroids
300
Non-Pyrethroids
120
Pyrethroids
Chloronicotinyl
Pyrethroids
Chloronicotinyl
200
90
60
100
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
100
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
300
Melons
250
80
60
Leafy
Vegetables
40
200
Melons
Leafy
150 Veg
Cotton
Cotton
100
20
50
Relative Whitefly
Population Abundance
Leafy
Vegetables
F11
F8 F9
F7
F12
F3 F4 F5 F6
F13
J
F1
F2
Alfalfa
F M A M J Ju A S
O N D
Relative Whitefly
Population Abundance
0
F10
Leafy
Vegetables
Buprofezin
12
Chloronicotinyl
4
6
Melons
4
2
F3 F4
F2
F8
F9
F1
F11
J
F10
F12
Alfalfa
F M A M J Ju A S
Cotton
Leafy
Veg
Alfalfa
0
F6 F7
F5
Leafy
Vegetables
Non-Pyrethroids
Pyrethroids
8
Alfalfa
Alfalfa
0
Pyriproxifen
0
8Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Cropping System (Acres x 1000)
30
Insecticide Usage ( Treated Acres, x1000 )
150
16
Pyriproxifen
Leafy
Vegetables
O N D
Relative Whitefly
Population Abundance
Pyriproxifen
Buprofezin
Cropping System (Acres x 1000)
Insecticide Usage (Treated Acres, x1000)
Yuma
Cropping System (Acres x 1000)
• Insecticide Use Patterns
• Seasonal Crop Diversity
• WF Population Dynamics
Leafy
Vegetables
F5 F6
F7
F3F4
F2
F8
F1
F10
Alfalfa
Leafy F9
Vegetables
J F M A M J Ju A S O N D
Palumbo et al. 2001
Defining a Crop Community
1) Multi-crop Community
• Cotton
• Melons
• Vegetables
“Crops grown within a 2 mile
radius of each other during year”
2) Cotton Intensive
3) Melon / Cotton Intensive
1. Limit Neonicotinoid Uses
Multi-Crop Communities………..additional guidelines
• No more than 1 use per crop in
melons and vegetables
• Soil at-planting recommended.
• Split applications are not
recommended
• Do not
apply foliar
neonicotinoid following the use
of a soil applied neonicotinoid
• Do not apply any
neonicotinoid
cotton
product to
Resistance Risks with
Shared Neonicotinoid Uses in a MCC
(eg., Yuma – potential usage)
Spring/Fall
Melons
Neonicotinoid
Leafy
Vegetables
Relative Whitefly
Population Abundance
Cotton
Not Sustainable
Preserve a Neonicotinoid-free Period
in Multi-Crop Communities
Spring/Fall
Melons
Neonicotinoid
Leafy
Vegetables
Cotton IRM
Program
II
I Knack,
III
Non Courier
IGR
s
Pyr
Oberon,
Pyr Dan/Ort
Relative Whitefly
Population Abundance
Cotton
Will Adoption of these Guidelines
Passive “De facto” IRM
Proactive IRM
Sustain the efficacy of Neonicotinoids
in Multi-Crop Communities
???
Grower / PCA Assessment
Anecdotal Evidence
• Since 2003 Guidelines have
definitely
created awareness of the issue
“I apologize, I sprayed some Intruder
on my cotton today”
Yuma PCA –July 2003
Grower Survey Data
• 2005
Cotton Insect Losses Workshop
Yuma Co., 8 PCAs responded (4987 acres)
- 4 had used Intruder on cotton
~ 27% of the acres, 1.3 sprays
2006 Head Lettuce Insect Losses Workshop
- Do not apply a foliar neonicotinoid following a soil use
Measurement of Group Adoption of Guidelines
•
Compliance is voluntary
•
Section level pesticide records ( 1080 - pesticide use reporting )
•
Measure temporal & spatial changes in adoption
•
Neonicotinoid usage in cotton within Multi-crop Communities
Crop Community
• GIS-geo referenced
• 9-section clusters
• 2 mile radius
• CI, CM, MCC
Analysis (2001-2005)
• Pesticide use data
overlaid on GIS maps
• Hypothesis:
Use in cotton
- MCC = 0
- CI > MCC
ile
s
m
2.
1
N sections sampled
randomly
1.5 miles
Melons
Leafy Vegetables
Cotton
Community-level Neonicotinoid Use in Cotton
Hypothesis: 0 use in MCC
40
% of Cotton Fields Treated with Neonicotinoid
Cotton-Intensive
Multi-Crop
30
20
Cross-Commodity
Guidelines
10
0
2001
2002
Centric
2003
2004
2005
Intruder
Challenges and Constraints to Sustained Efficacy
A. Generic imidacloprid
•
•
Lower $ cost = higher use rates
Confusion in class recognition (foliars)
B. Expansion of neonicotinoid labels
•
•
•
New Crop Labels - on melons and leafy vegetables
Home / Garden / Ornamental
Alfalfa/Seed Crops
- imidacloprid
- future registrations ?
C. Market forces
•
•
Promote Neonicotinoid use in Cotton
Leafy Vegetables / Melons
Challenges and Constraints to Sustained Efficacy
D. New Chemistry in the Pipeline
•
Trends toward more selective chemistries
•
Grower attitudes:
“Industry always comes through with new technology”
•
Industry attitudes:
“Resistance is a source of innovation”
E. Complacency and apathy
•
•
“Little Suzy needs new shoes”
•
Sloppy soil applications on vegetables and melons
Reduced rates / split (multiple) applications