Management of Western Flower Thrips in SE Florida

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Management of Western Flower Thrips in SE
Florida JOE FUNDERBURK, UNIVERSITY OF
FLORIDA CHARLES MELLINGER
Photo Cheryle ODonnell
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Frankliniella occidentalis western flower thrips

Photo Cheryle ODonnell
Established in the southern US (and northern
Florida) in the 1980s Key vector of Tomato
spotted wilt virus Very destabilizing to
integrated pest management programs including in
northern Florida
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Tomato spotted wilt virus symptoms on pepper
Flecking on pepper due to feeding
by Frankliniella occidentalis
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Tomato spotted wilt virus

• Family BUNYAVIRIDAE
• Genus Tospovirus
• Species Tomato spotted wilt virus
• Common name TOMATO SPOTTED WILT (important
  worldwide species and in Florida)
• About 1000 plant species are known hosts
• Seven species of thrips are known vectors

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PEPPER
Capacity of minute pirate bugs, Orius insidiosus,
to reduce thrips populations
Photo Joe Funderburk
Predator-Prey Ratio Management Guides 1 predator
per about 180 thrips population suppression 1
predator per 50 thrips control
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50
PEPPER
0.8
fenpropathrin
40
30
0.4
20
10
0
0.0
0.8
spinosad
12
per flower
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Thrips per flower
0.4
4
Pirate bugs
0
0.0
0.8
untreated
12
8
0.4
4
0
0.0
14 17 19 21 24
28 31 3
May June 1996
Funderburk, Stavisky Olson 2000
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Thrips/Orius Ratio in Peppers
Ratio above this line, spray
GCC June 2007
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Spinetoram Bioassays of Western Flower Thrips
from Palm Beach County, March 2008
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Spinetoram Bioassays of Thrips in Pepper Fields
IPM field
No IPM
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INSECTICIDES FOR FRUITING VEGETABLES THAT
CONSERVE MINUTE PIRATE BUGS

• RADIANT thrips and other pests
• TESORO thrips and other pests
• REQUIEM thrips, aphids, whiteflies
• INTREPID lepidoptera
• AVAUNT lepidoptera
• Bts lepidoptera, coleoptera
• ECOTROL thrips and other pests

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INSECTICIDES KNOWN TO INDUCE WESTERN FLOWER
THRIPS IN PEPPER

• Fenpropathrin
• Lambda-cyhalothrin
• Dinotefuran
• Zeta-cypermethrin bifenthrin
• Esfenvalerate
• Permethrin

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RECOMMENDATIONS FOR PEPPER

• Distinguish between adult and larval thrips and
  identify adult thrips
• Economic thresholds about 10 western flower
  thrips per flower and about 3 thrips larvae per
  fruit
• When peppers are flowering, use insecticides for
  thrips and other pests that conserve minute
  pirate bugs
• Never use insecticides that induce western flower
  thrips
• Ultraviolet-reflective mulch
• Sunflower and other refugia provide a source for
  minute pirate bugs
• Vertically integrate management of thrips and
  other pests including pepper weevil and
  lepidoptera

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TOMATO
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Dimples on tomato due to oviposition of
Frankliniella occidentalis
Flecking on tomato due to feeding
by Frankliniella occidentalis
Ring spots and fruit deformity from
tomato spotted wilt infection
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Recommendations for western flower thrips in
Florida

• Distinguish between adult and larval thrips and
  identify adult thrips
• Economic thresholds about 1 western flower
  thrips per flower and about 3 larvae per fruit
• Alternate between Radiant and other efficacious
  insecticides
• Avoid using insecticides that induce western
  flower thrips populations
• Ultraviolet-reflective mulch
• Vertically integrate management program for
  thrips with management of other pests including
  whiteflies