Ecology and Management of Scirtothrips dorsalis

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Ecology and Management of Scirtothrips dorsalis
Presented By Dr. Joe Funderburk, UF/IFAS

• Contributing Authors
• UF/IFAS J. Funderburk, and L. Osborne

A.C. Hodges, UF/IFAS, SPDN (ed.)
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POPULATION ATTRIBUTES OF THRIPS
? Vagile (excellent invaders, mobile)? Broad
host range? Short generation time?
Predisposition to parthenogenesis? A competitive
breeding structure promoting aggregation and
exploitation of localized optimal conditions
Mound. 1997. Thrips As Crop Pests (Lewis, ed.)
CAB International
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Host Range for Frankliniella occidentalis

• 50 of 55 plant species in 22 families were food
  hosts for the adults in a survey in Central Chile
• 43 of 55 plant species were reproductive hosts

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Plant Hosts for Frankliniella occidentalis in the
Aconcogue Valley, Chile
Number of Families or Species
Ripa, Rodriguez, Funderburk, Espinoza,
unpublished
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Life History of Pest Thrips

• 30 to 40 days for a complete generation
• 6, 5, and 5 days for development of egg, larva,
  and pupa
• Pollen doubles or triples fecundity
• Strong aggregation tendencies for flowers of
  Thrips and Frankliniella species
• Scirtothrips aggregate on young foliage and
  flowers

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Reproduction in Thrips

• In most Thysanoptera, reproduction requires
  copulation
• Parthenogenesis common
• In most species, fertilized eggs have the full
  diploid number and become female unfertilized
  eggs are haploid and become males

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Integrated Pest Management
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Natural Enemies of Thrips

• PREDATORS Anthocorids, Chrysopids, Nabids,
  Aeolothrips, Phlaeothrips, predatory mites
  (Euseius sojanensis)
• PARASITES Thripinema (Tylechida
  Allantonematidae)
• PARASITOIDS Chalcidoidea (Megaphragma sp.)
  Ceranisus (Eulophidae)
• PATHOGENS Fungal pathogens recently reported as
  important for Scirtothrips dorsalis in India

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Important Worldwide Predators of Thrips

• ORDER HEMIPTERA
• FAMILY ANTHOCORIDAE
• commonly, pirate bugs
• GENUS Orius
• SPECIES insidiosus
• COMMON NAME
• Insidious flower bug

Photo Stuart Reitz
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PEPPER
Intrinsic capacity of Orius insidiosus to reduce
Frankliniella occidentalis populations
Photo Joe Funderburk
Predator-Prey Ratios 1 217 population
suppression 1 51 rapid local extinction
Sabelis Van Rijn (1997) Thrips as Crop Pests.
(Lewis, ed.) CAB International, UK
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50
0.8
fenpropathrin
PEPPER
40
30
0.4
20
10
0
0.0
0.8
spinosad
12
per flower
8
Thrips per flower
0.4
4
Pirate bugs
0
0.0
0.8
untreated
12
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Funderburk, Stavisky Olson 2000 Environ.
Entomol. vol. 29 (2) 376-382
0.4
4
0
0.0
14 17 19 21 24
28 31 3
May June 1996
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Commercial Pepper FieldThomas Smith Farms,
Greensboro, FL
RECOMENDATION FOR PEPPER
PRODUCERS
CONSERVE ORIUS POPULATIONS BY THE SELECTIVE USE
OF TACTICS
Courtesy Glades Crop Care, Inc.
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Aconcague Valley, Chile
120
120
1999-2000
100
100
Annual cycle of abundance of western
flower thrips in alfalfa in the southern
hemisphere
80
80
60
60
Thrips per 5 terminal shoots in alfalfa
40
40
20
20
0
0
Apr May Jun Jul Aug Sept Oct Nov
Dec Jan Feb Mar Apr
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Dynamics of Frankliniella occidentalis in Alfalfa
in Central Chile as Influenced by Pirate Bugs
291
0
Number of total thrips per Orius insidiosus
140
Number of thrips per 5 terminal shoots
13
68
0
81
64
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16
16
17
Ripa, Rodriguez, Funderburk, Espinoza,
unpublished
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Species of Thripinema, Nematode Parasites of
Thrips

• T. nicklewoodi (North America)
• T. khrustalevi (Asia, South America)
• T. fuscum (North America)

• T. aptini (Europe)
• T. reniroai (Asia)
• Undescribed species (New Zealand)

Photo Chris Tipping
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EFFECTS OF Thripinema PARASITISM ON EGG
PRODUCTION OF THRIPS HOST
3
Not parasitized, healthy host
2
1
0
3
Fecundity of Frankliniella fusca (eggs per day)
Infected when 3-day-old adult
2
1
0
3
2
Infected when 1-day-old adult
1
0
3
2
Infected when Larvae II
1
0
3
Infected when Larvae I
2
1
0
0
5
10
15
20
25
Age of Adult FemaleThrips (days)
Sims, Funderburk Boucias 2005 J. Nematol.
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parasitized F. fusca
TSW
F. fusca
larval thrips
80
Parasitism nearly prevents mid late season
cycles of TSW
60
Funderburk et al. 2002. Environ. Entomol. 31(3)
558-563.
TSW
40
PEANUTS
20
0
75
80
60
50
F. fusca parasitized by T. fuscum
Thrips per plant
Parasitism suppresses thrips mid and late season
40
25
20
0
0
20 May 9 Jun 29 Jun 19 Jul 8 Aug
28 Aug 17 Sept
1999
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Recommendations for Peanut Producers

• Cultivars partially resistant to Tomato spotted
  wilt virus
• Biological control
• Planting date
• Insecticides that conserve key natural enemies

Photo Joe Funderburk
Funderburk Latsha. 2005. Nematodes As
Biocontrol Agents. ( Grewal et al. eds.) CAB
International, UK
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TOMATO
UV mulch
Photo Joe Funderburk
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ACTIGARD (Syngenta)

• Acibenzolar-S-methyl
• Substitutes for the natural systemic-acquired-resi
  stance molecule salicylic acid that is essential
  for activation of systemic acquired resistance
• Six applications on tomatoes at two-week
  intervals beginning at transplanting

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Recommendations for tomato producers

• UV mulch effective in reducing thrips invasion
  and primary spread of TSWV
• Actigard recommended when using UV mulch to
  reduce sprays of copper and other pesticides that
  reduce the UV reflectance of the mulch
• Insecticides useful in suppressing thrips larvae
  and secondary spread of TSWV

Source Momol et al. 2004. Plant Disease 88(8)
882-890
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Thrips and Tomato Spotted Wilt

• Regulation of vector populations with
  insecticides is not sustainable producing
  undesirable environmental and economic
  consequences
• Integrated pest management is effective,
  environmentally friendly, and sustainable
• Management programs developed from knowledge of
  vector population dynamics and disease
  epidemiology

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Chilli Thrips Natural Enemies

• Egg Parisitoid
• Megaphragma sp. (Chalcidoidea)
• 53.2 parasitism on grapes in Japan
• Predatory Mite
• Euseius sojaensis
• 1.4 larvae/hr
• 5.4 larvae/day

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Ornamental Plant Hosts of Concern
For the latest information on chilli thrips and
ornamental plants, visit http//mrec.ifas.ufl.edu/
lso/thripslinks.htm
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Ornamentals

• abamectin (Avid)
• acephate (such as Orthene or Orthonex)
• acetamiprid (TriStar)
• azadirachtin (such as Azatin, Neem oil) (not
  labeled for thrips)
• cyfluthrin (Decathlon, Discus, Bayer Advanced
  products such as Tree and Shrub Insect Control or
  Rose and Flower Insect Killer)
• disulfoton (such as Di-Syston Systemic
  Insecticide Granules)
• imidacloprid (Marathon, Merit, Discus and the
  Bayer products listed above)
• novaluron (Pedestal)
• spinosad (such as Conserve)

Materials in yellow would be suitable for use by
homeowners if used according to the labeled
instructions.
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Overall Conclusions

• Management of S. dorsalis in the landscape
  requires an integrated approach that includes a
  detailed understanding of pest biology, natural
  enemy complexes, and host resistance.
• Chemical control options are also available and
  may be necessary in some cases.
• Chemical control options or destruction of plant
  material is the only option for retail nurseries
  as long as S. dorsalis remains a regulated pest.

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Disclaimer

• The use of trade names in this presentation is
  solely for the purpose of providing specific
  information. UF/IFAS does not guarantee or
  warranty the products named, and references to
  them in this publication does not signify our
  approval to the exclusion of other products of
  suitable composition. All chemicals should be
  used in accordance with directions on the
  manufacturer's label. Use pesticides safely. Read
  and follow directions on the manufacturer's label.

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