ipm of western flower thrips my discussion points
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Control of Western Flower Thrips Through Integrated Pest Management in Tomato and Pepper P resented by: Dr. Charles Mellinger, Glades Crop Care, Inc. August 29, 2008. IPM of Western Flower Thrips my discussion points. 1. Vector of Tomato Spotted Wilt Virus (TSWV) - PowerPoint PPT PresentationTRANSCRIPT
Control of Western Flower Thrips Through
Integrated Pest Management in Tomato and Pepper
Presented by: Dr. Charles Mellinger, Glades Crop Care, Inc.
August 29, 2008
1. Vector of Tomato Spotted Wilt Virus (TSWV)
2. Current infestation areas of thrips & TSWV
3. IPM• Correct identification required for correct response• Economic thresholds with and without TSWV• Control measures• Resistance management• Preventative practices
IPM of Western Flower Thripsmy discussion points
2. Current Situation - Thrips & TSWV
• TSWV reservoirs—inadequate knowledge
• Positive TSWV Identification in: – Tampa area peppers & ornamentals– Homestead tomatoes– Emilia– Georgia Transplants
• Summary – very little at this point compared to Southeastern U.S.
TSWV Symptoms
Emilia with TSWV Symptoms
2. Current Situation - Thrips in South Florida
• Historically only Florida flower thrips
• Recently small pockets of Western flower thrips
• Homestead & adjacent areas with Thrips palmi
• Populations changing and moving• New large populations of WFT-east coast• Significant population of other important thrips
• Summary – thrips are becoming very important in South Florida crops
2006 - Present
1985 - 2005
F. tritici
F. occidentalisF. fusca
F. bispinosa
Thrips palmi
3. IPM• Correct identification of thrips’ genus/species
required for correct response• Economic thresholds are different• Chemical control choices are different
• No pyrethroids• Rotation and resistance management are
different
Insecticide Treatment for WFT Larvae Control in Spring Tomatoes
Number of Thrips Larvae per 10 Leaves
05
1015202530354045
UTC Spintor 2SC6 fl oz/A
Baythroid2E 2.8 fl
oz/A
Radiant 6 fl oz/A
3 DAT7 DAT8 DAT
Dr. Tom Kuhar – VA Eastern Shore
WFT Adults & Minute Pirate Bugs (MPB) Collected from Pepper Blooms
Ft. Pierce, FL, Spring 2007May Untreated
checkPyrethroid Intrepid
WFT MPB WFT MPB WFT MPB8 48 5 94 4 83 4
10 82 8 136 0 78 1014 54 12 148 2 30 1116 64 10 245 0 144 621 86 8 147 1 60 323 50 4 251 0 77 529 79 3 182 1 34 12
3. IPM-Preventive Practices• Monitoring
– Pre-planting: weeds and surrounding fallow– During crop production– During crop and post crop destruct - Impact on adjacent
crops and fields
• Varietal resistance—few varieties in pepper to TSWV
• Reflective mulch---reduced #’s and incidence
• Adjacent grower notifications
• Conservation of the Thrips predator—The Minute Pirate Bug—Orius insidiosus
Minute Pirate Bug (MPB)Orius insidiosus
Larva Adult
Sunflowers in pepper for thrips control: more Orius, fewer thrips
Orius density in field without sunflower
Gray: <0.01-0.05 Green: 0.05-0.1 Blue: 0.1-0.5 Red: >0.5
Orius per pepper flower
Orius density in field with sunflower
Gray: 0.01-0.05 Green: 0.05-0.1 Blue: 0.1-0.5 Red: >0.5
Orius per pepper flower
Thrips density in field without sunflower
Gray: <1-5 Green: 5-15 Blue: 15-30 Red: >30 Thrips per flower
Thrips density in field with sunflower
Gray: <1-5 Green: 5-15 Blue: 15-30 Red: >30 Thrips per flower
Thrips and Orius density on pepper flowers
05
10152025303540
Dates
Thrip
s/pe
pper
flow
er
0
0.05
0.1
0.15
0.2
0.25
Oriu
s/p
eppe
r flo
wer
Thrips - SunflowerThrips - No SunflowerOrius - SunflowerOrius - No Sunflower
Impact of insecticides on prey:predator ratios in peppers
0.0
100.0
200.0
300.0
400.0
500.0
600.0
700.0
0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0
Average MPB per sample
Ave
rage
thrip
s pe
r sam
ple
Gamma-cyhalothrin Treatments
Permethrin Treatments
Untreated Check
Methoxyfenozide Treatment
Summary
• WFT expanding in South Florida
• WFT excellent vector of TSWV• Augment pepper crop with sunflower
• Few WFT Pesticide controls
• Must ID thrips population for correct response
• Must scout for correct response