IPM - Thrips

IPM of Thrips under greenhouse condition of Jordan

1. THRIPS

2. Order Thysanoptera
Thrips
4 narrow,
fringed wings
Tube-like
mouthparts

3. Adult thrips

4. Order Thysanoptera
Family Thripidae
–Western Flower Thrips Frankliniella occidentalis
–Onion thripsThrips tabaci
–Greenhouse thripsHeliothrips haemorrhoidalis

5. WFT

6. Greenhouse thrips

7. Westernflowerthrips(WFT)hasthreecolorforms:
Paleformthatiswhiteandyellow,exceptforslightbrownspotsor
blemishesonthetopoftheabdomen.
Intermediateformwithadarkorangethoraxandbrownabdomen.
Darkformthatisdarkbrown.
Onionthrips(Thripstabaci):
darkerthanWFT,andsmallerinsize,with7segmentsinantennae
comparedwith8segmentsinWFT.
AdultGreenhousethrips:
Adultsaretiny,black,insectswithwhitishtotranslucentwingsfolded
backovertheirthoraxandabdomen.Legsarealsoawhitishcolor.
Nymphsarewhitishtoslightlyyellowishincolorandproduceaglobule
offecalfluidatthetipoftheirabdomen.
These globules of fluid increase in size until they fall off and another
one begins to form, resulting in a characteristic spotting of the
infestation area with black specks of fecal material.

8. Western Flower Thrips
Frankliniella occidentalis
Biology & Lifecycle:
–Thripsaretinyinsectsthathavefourfeatherlikewings,each
consistingofathicksupportingstrutwithfinehairsonthefront
andhindedges
–Thripsinsertindividualeggsintothedevelopingflowerbudsand
fruitpodsofpepperandtomato.
–Theeggshatchinabout6days.Thripsgothroughsixlifestages:
egg,firstinstar,secondinstar,prepupa,pupa,andadult.
–Thefirsttwoinstarsandadultsfeedbypiercingand
removingcontentsofindividualplantcells.
–Larvaldevelopmentintheflowersandsmallfruitsrequires6to8
daysdependingontemperature.
–Theadultsliveabout3weeksandfeedprimarilyonflowertissues
andpollen.Pollen-feedingincreasesfecundity2to4fold.
–Generationalcyclestakeabout20daysinhotweatherandas
longas60daysinthewinter

10. Western flower thrips adult femaleWestern flower thrips larva

11. Adult :
–Verysmall(2.5mm),lightyellowwithfringe
wingsand8-segmentedantennae.
–Adultsaggregateintheflowers,andarerarely
foundontheterminal,unexpandedleaves.
Larvae:
–Minuteandwhite,bothlarvalinstars
aggregateintheflowersandsmallfruit.
–Pre-pupaemovetothesoilsurfaceand
pupatebeneaththesoilsurfaceunderthe
plant.

12. Host range:
–Reproduction occurs on peppers (Capsicum spp.),
tomatoes and a wide range of crops, weeds and native
plant species.
–Adults feed on the flowers of plant species that are not
reproductive hosts as well.
Damage & Economic Importance:
–Akeypestoftomato,pepperandothercrops.
–Cosmeticdamageonfruitsfromfeedingisaneconomic
problemundersomeconditions.
–Adultfemaleslayindividualeggsonthesmallfruitinside
oftheflowerresultinginhalospots.
–Feedingbytheadultsandlarvaecanresultinfleckingon
thesurfaceoffruitandunderheavyinfestations,fruit
deformity.
–F.occidentalisistheprimaryvectorofTomatospottedwilt
virus(TSWV)whichrendersfruitunmarketable.

13. Early symptoms of thrips
infestation on cucumber

14. Symptoms of thrips infestation on
cucumber

16. Halo spots on fruit due to egg
laying into the tomato
Tomato spotted wilt damage to
tomatoes

17. Fruit severely affected by TSW.

18. Fruit mildely affected by TSW

19. Fruit that showed TSW symptoms

20. Monitoring
Traps:
–Bluestickycardsaremostattractivethrips.However,yellowcards
areeasiertocountandmorecommonlyusedforinsectmonitoring.
Placeyellowstickycardsverticallyinthecropcanopy,withthelower
one-thirdofthetrapintheleavesandtheuppertwo-thirdsabovethe
leaves.Asthecropgrows,thetrapswillneedtoberaised.
Scouting:
–Frequentmonitoringofonceortwiceweeklyisneededtoassess
westernflowerthripsnumbersandtodeterminetheincidenceof
TSWV.
–ThetotalnumberofThripsofallspeciescanbeestimatedinthefield
bybeatingindividualflowersontoawhiteplasticboard.
–Thripsmustbeplacedinvialsofalcoholandexaminedat40X
magnificationusingastereoscopeinordertodeterminewestern
flowerThripsfromtheotherflowerThripsspecies.

22. ActionThresholds:
–Considertreatingifanaverageof5to10thripsper
cardperweekispresent(1trap/900sqm)
–Intomato,>0.5adultsperflower.Iftomatospotted
wiltincidenceexceeds5%inthefield,onceperweek
applicationsofaninsecticideforcontrolofthelarvae
reducesspreadofthediseaseinsusceptible
cultivars.
–Inpepper,2to3larvaeoradultsperfloweris
tolerable.Areducedriskinsecticidethatdoesnot
suppressnaturalpopulationsofpredatoryminute
piratebugscanbeusedtosuppressadultsand
larvae.

23. Cultural Control
–Becausewesternflowerthripsandgreenhousethripsfeedona
largevarietyofplantspecies,keepproductionareasfreeof
weeds,whichcanserveashostsforthripspopulations.
–Coveringopeningstothegreenhouse&ventilationopeneing
withfinescreensdoesexcludemostthrips.
–Carefullyinspectplantsbeingbroughtintostartanewcropto
ensurethattheyarefreeofthripsandotherpests.
–Ultraviolet-ReflectiveMulch:UV-reflective(aluminum)mulch
reducestheintroductionofwesternflowerthripsadultsinto
productionfields.Thisisthemosteffectivetactictocontrol
primaryspreadofTSWV(i.e.thripsacquiretheviruswhen
developingonplanthostsoutsidethefield).
–DoNotOver-Fertilize:Over-fertilizationwithnitrogenincreases
thenumberofwesternflowerthripsandtheincidenceofTSWV.
–ResistantCultivars:CultivarsresistanttoTSWVareavailablefor
tomatoesandpeppers.
–Distinguishingtheadultsfromotherflowerthrips(F.bispinosa)
andtheeasternflowerthrips(F.tritici)isnotpossibleusinga
handlens.

24. Natural Enemies
Thekeynaturalenemycapableofsuppressing
populationsistheminutepiratebug,Oriusspp.
Thesepredatorsnaturallyinvadefieldsand
managementprogramsofpepperandother
cropsshouldbedesignedtoconserveits
populations.
Nonaturalenemiesareimportantinsuppressing
westernflowerthripsintomatoduetoit’s
nutritionalpoorpollengrain.So,plantingpepper
withtomatoprovidethepredatorappropriate
foodandenhancethripscontrolintomatofields.

25. Adult minute pirate bug

26. Thripobius semileteus ( thrips parasites )

27. Pepper flower infested by thrips and
larva of aphids lion feeds on thrips

28. Chemical Control
–Duringperiodsofintenseinfestations,
reducingthripsnumbersbelowtheaction
thresholdwithnaturalenemiesisnotpossible.
–Spraytomatoeswhennumbersofadultsor
larvaeexceedtheactionthreshold.
–Usereduced-riskinsecticidestoconserve
minutepiratebug,Oriusspp,populationsin
pepper.NaturalEnemiestypicallycontrolthe
F.occidentalisformostoftheproduction
season.

29. Class Pesticide Class Pesticide
biological Beauveriabassianacarbamate methiocarb
(Mesurol 75W)
botanical cinnamaldehyde
(Cinnacure)
insect
growth
regulator
azadirachtin
(Azatin XL Plus)
Pyrethrum azadirachtin
(Ornazin 3%EC)
pyrethrin/rotenone
(Pyrellin EC)
novaluron
(Pedestal)
macrocyclic lactone abamectin oil clarified
hydrophobic
extract of neem
oil
(Triact 70)

30. neonicotinoid imidacloprid
(Marathon 60 WP)
organo-chlorine endosulfan
(Endosulfan 3EC)
imidacloprid
(Marathon 1G)
(Marathon II)
organo-phosphateacephate
(Address)
nicotine nicotine
(Nicotine Smoke
Generator)
acephate
(Orthene T, T&O
Spray) 75WP
organo-phosphate/
pyrethroid
chloropyrifos/
cyfluthrin
(PT Duraplex TR)
acephate
(1300 Orthene TR)
soap potash soap
(Insecticidalsoap)
(M-Pede)
chlorpyrifos
(PT DuraGuard
ME)
spinosyn spinosad
(Conserve SC)

31. Resistance Management
FewinsecticidesareeffectiveinsuppressingF.
occidentalis.
Resistancehasdevelopedtomanyproducts
includingcarbamate,organophosphateand
syntheticpyrethroidinsecticides.
Resistancetoneonicotinoidinsecticidesalsois
reported.
Alternativeculturalcontrolandplantresistance
tacticsarethebestoptionstocontrolthripsandto
avoidthedevelopmentofresistance.
Rotatechemicalclasses,althoughthisdoesnot
guaranteeagainstthedevelopmentofinsecticide
resistance.