1. Management of Western Flower Thrips in SE Florida
JOE FUNDERBURK, UNIVERSITY OF FLORIDA
CHARLES MELLINGER
Photo Cheryle O’Donnell

2. Frankliniella occidentalis western flower thrips
Photo Cheryle O’Donnell
Established in the southern US (and northern Florida)
in the 1980’s
Key vector of Tomato spotted wilt virus
Very destabilizing to integrated pest management
programs including in northern Florida

3. Tomato spotted wilt virus symptoms on pepper
Flecking on pepper
due to feeding by
Frankliniella
occidentalis

4. 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

5. PEPPER Predator-Prey Ratio Management Guides
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
So if we can alter the predator – prey ratio, we can suppress thrips populations quickly and persistantly

6. PEPPER Thrips per flower Pirate bugs per flower May & June 1996
Western flower thrips
thrips larvae
Orius 50
PEPPER
0.8
fenpropathrin 40 30
0.4 20 10
0.0
0.8 12
spinosad
per flower
Thrips per flower 8
0.4 4
Pirate bugs
0.0
0.8 12
untreated 8
0.4 4
0.0
May & June 1996
Funderburk, Stavisky &Olson 2000

7. Thrips/Orius Ratio in Peppers
Ratio above this line, spray
GCC June 2007

8. Spinetoram Bioassays of Western Flower Thrips from Palm Beach County, March 2008

9. Spinetoram Bioassays of Thrips in Pepper Fields
IPM field
No IPM

10. 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
Bt’s lepidoptera, coleoptera
ECOTROL thrips and other pests

11. INSECTICIDES KNOWN TO INDUCE WESTERN FLOWER THRIPS IN PEPPER
Fenpropathrin
Lambda-cyhalothrin
Dinotefuran
Zeta-cypermethrin & bifenthrin
Esfenvalerate
Permethrin

12. 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

13. TOMATO

14. 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

15. 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