Thrips are small, winged insects in the order Thysanoptera that cause damage to many agricultural crops. Some key points: - Thrips transmit tospoviruses in a circulative and propagative manner as they feed. Frankliniella occidentalis and Thrips tabaci are two major pest species. - They have asymmetrical mouthparts and use a unique stylet-sheath system to pierce plant tissues and feed. This can cause symptoms like leaf curling, crumbling, and discoloration. - Life cycles include egg, two nymphal instars, prepupa, pupa and adult stages. Both nymphs and adults feed

1. WELCOMESSNAIK
TNAU

2. ENT 807
PLANT HEALTH DIAGNOSTICS AND MANAGEMENT
CPPS,TNAU,
COIMBATORE-641 003
NAME :SABHAVAT SRINIVASNAIK
ID. NO: 2015800506
YEAR: I Ph. D (2015)
DEPT.: AGRICULTURAL ENTOMOLOGY

3. Taxonomic position
Kingdom: Animalia
Phylum : Arthropoda
Class : Insecta
Order : Thysanoptera
Family : Thripidae
Genus : Thrips & others
Bladderfoot/Woodlouse/fringed
 Common name –Thysanoptera-thrips
 World wide 6000/777 genera/ 60 fossil
 Permothrips longipennis Martynov, 1935
 Pest & Predator (Size : 0.5 to 14 mm)-Aphids, Mites
 Asymmetrical mouthparts-unique
 Yellow, yellowish-brown or black
 Disturb-Run/Leap/Curving-abdomen
 Thripidae comprises at least 1700 species
 It is important pest species. Sueo Nakahara, 2005 & Imms, 1977
Thysanos ("fringe")
pteron ("wing")
 1744 -Physapus - De Geer
 1758- Thrips - Linnaeus
 1836-Thysanoptera-Haliday

4. Terebrantia Tubulifera
………………………………………………………………………………………………………
Family:
Family : Phlaeothripidae
1. Aeolothripidae
2. Thripidae
Wing venation is present
Wing venation is absent
Imms, 1977

5. Terebrantia
Tubulifera
Imms, 1977

6.  Phytophagous, Pollinophagous
 Mycetophagous, Predaceous
 Foliage and flower/pollen/fruit/gall
 Vectors for the plant pathogens
 Yield loss is 35 % to 55 %
 Small size and high reproductive capacity
 1090 host-plant species in 15 monocot
& 69 dicot families world wide
 >100 species are major pests of crop plants
(Parrella et al. 2003)
A.Phytophagous B. Predators
C. Vectors

8. 94 percent of the animal vectors are the arthropods
Arthropods
I. Aphids II. Leafhoppers/
Planthoppers
III. Whiteflies
Thrips
Mites
vMBs/coccids

9. S.No Based on the
retention
Based on the
route
Latest Classification
i) Non Persistent Stylet borne Non circulative a) Non persistent
b) Semi persistent
ii) Semi-persistent Circulative Circulative a) Circulative
b) Circu-propagate.
iii) Persistent
Reddy, 2010

10. Moritz and Mound, 2004

12. VECTORS- THRIPS
Frankliniella occidentalis (The Western flower thrips)
F. schultzei
F. fusca (Tobacco thrips)
F. intonsa
F. bispinosa
F. zucchini
F. gemina
F. cephalica
Thrips tabaci (The onion thrips)
T. palmi
T. setosus
Scirtothrips dorsalis
Ceratothrioides claratris
Dictyothrips betae
(Riley et al, 2011)
14 species of thrips transmitting tospoviruses

13. F. occidentalis F. schultzei F. fusca F. intonsa
F. bispinosa F. zucchini F. gemina F. cephalica
T. tabaci. T. palmi T. setosus C. claratris

14. Agrios, 2005

15. The thrips- tospovirus relationship is unique
Circulative and propagative manner and are transstadially passed in the vector
(it can transmit throughout life ) (Nagata & Peters, 2001)
Acquisition- First & early second instar immature larvae (5min)
Transmission-Second instar larvae just before pupation and adult
(30 min)
(Chatzivassiliou et al., 2002)

16.  The primary salivary glands,
midgut, and visceral muscles of
the first larval stage are
compressed into one area of the
thorax where they lie in direct
contact with one another through
the early second instar stage
 The virus moves from the midgut
and muscles to the salivary gland
when these tissues lie in direct
proximity to one another in the
larval insect
Moritz et al., 2004
 As insect grows, the brain and primary salivary glands move forward, while
the first midgut loop moves back into the metathorax, resulting in spatial
separation of these organs and preventing virus movement between these
tissues

17. Moritz et al., 2004Moritz et al., 2004

18. Riley et al., 2011

19. www.omafra.gov.on.ca

20.  Both nymphs and adults will suck the sap
 Under surface of the leaf between the veins and vein lets
 Asymmetrical piercing mouthparts-unique
 Lacerate and suck the oozing sap
 Host range: brinjal, cotton, groundnut, castor, bottle gourd, guava, tea.
A. Before stylet penetration no contact of the mouth
cone with the leaf surface
B. Insertion of the mandible
C. Insertion of the maxillary stylets
D. Feeding of the sap
E. Stops penetration and mouth cone contact
Chisholm and Lewis, 1984

21.  Curling upward, crumbling and shedding
 Bronzing, flecking, silvering
 Browning and early flower drop
 Virus symptoms may resemble other plant disease
symptoms or nutritional issues.
Wilting,
Black streaking,
Necrotic black spots,
Concentric circles of light and dark coloration
Vasantha raj david, 2012

22. 1. Field diagnosis
1.Morphological
2.Molecular
Onion: Thrips tabaci
 Winter season –Diapause –Debris
 Spring –fly to new field
 Parthenogenic reproduction
 young leaves in centre of onion neck
 I, II instars are active feeders
 Prepupa and Pupa –resting –soil/
scales
 Crowded-move to tip of the plant
 White to silvery in colour
 Reduced bulb size
 iris yellow spot virus
Tiny black “tar” spots of thrips excrement are evident on leaves with heavy feeding injury
1. Field diagnosis

23.  Both nymphs and adults lacerate the tender
leaves and suck the plant sap, causing yellow
(or) silvery streaks on the leaves of young
seedlings
 Terminal rolling and drying of leaves from tip
to base is the typical symptom of attack
 Damage both in nursery and main field
 Affected nurseries- pale yellow colour with
brown tips
 On passing the wet palm over the top of the
seedlings a large number of black adults and
yellowish nymphs stick to the palm
Rice Thrips: Stenchaetothrips biformis
Vasantha raj david, 2012

24. 2. Chilli thrips, Scirtothrips dorsalis
Upward curling and crinkling
Stunted growth
Fruit scarification
Mite
1. Field diagnosis

25. 1. Field diagnosis
Groundnut thrips
 White patches appearing
on the lower surface of
the leaves and distortion
of young leaflets.
 Dull yellowish-green
patches of the upper leaf
surface and brown
coloured (necrotic) areas
on the lower surface
Vasantha raj david, 2012

26. Rose thrips damage
Browning and flower drop
Vasantha raj david, 2012

27. Fringed wings
Tarsal bladder
Asymmetrical mouthparts

28. Chirothrips aculeatus Scolothrips longicornis
Limothrips angulicornis Tenothrips frici
Aptinothrips stylifer Frankliniella occidentalis
Bregmatothrips bournieri Limothrips angulicornis
Mirab-balou, 2013

29. Frankliniella occidentalis Thrips alliorum
Tenothrips frici Anaphothrips obscurus
Rubiothrips vitis
Chirothrips aculeatus
Megalurothrips distalis
Mirab-balou, 2013

30. Mirab-balou, 2013

32. Thrips palmi, T. tabaci, Frankliniella intonsa and F. occidentalis
Collected from the different quarantine stations
Lysis buffer used for isolation of the DNA
LTS2 Marker
Designed Primers:
PAL-ITS2F2 (5′ -TGTGATGTACGTGCACTGGA-3′),
TAB-ITS2F4(5′ -AACGATTHCCAGACTGCCC-3′),
INT-ITS2F1(5′ -GACCAGACTGTTCCGAGA-3′),
OCC-ITS2F6(5′-T GGTCGCTTCACCGCTTCCCG-3′),
ThripsITS2R3 (5′-CTCTCCTGAACWGAGGTCG-3′)
 3.5 percent gel electrophoresis
 Restriction enzyme RsaI
 4 Percent agarose gel

33. T. Tabaci
Frankliniella intonsa
F. occidentalis
Frankliniella tenuicornis
3.0 %
4 %RSaI
Nakahara and Minoura 2015

34. 25/5 wet palms
Top unopened leaves
Count 25 plants randomly
No./Leaf=1/Leaf
Rice
Other crops
Raghumurthi, 2010

35. 1. Cultural control  Grow tolerant varieties like ALR 3, Robut 33-1, Kadiri 3 and
ICGS 86031
 Uproot and destroy severely infected plants.
 Setting up of blue sticky traps at rate of 12 per
hectare in the field will check the thrips population
2. Mechanical control
3. Biological Control  Conserve bio agents like flower bugs (anthocorids), lady
bird beetles (coccinellids), praying mantis, green lace
wing (chrysopids), long horned grass hoppers, dragon
flies and spiders.
Dhaliwal, 2012

36. 4. Chemical control
 Seed treatment with imidacloprid 70 WS 7g/kg against aphids, leafhoppers
and thrips upto 8 weeks
 Spray Monochrotophos 36 SL 600 ml/ha
 Methyldemeton 25 EC 600 ml in 600 lit of water.
 Monocrotophos 320 ml mixed with neem oil 1lit and 1kg soap powder
mixed in 200lit of water twice at 10days interval.
 Neem oil or pungam oil at 2ml/ha will be very effective
 Spraying of fipronil 5 SC at 1.5-2.0ml/ha
 Thiacloprid 21.7 per cent SC 125ml/ha
 Thiamethoxam 25 per cent WG at 40g/ha @ 25, 45 and 60 DAS
 NSKE 5%
 Imidacloprid 200 SL @100 ml
Dhaliwal, 2012

37.  Common insects under thysanoptera-Thrips
 Economic important family-Thripidae
 Unique characters of thrips-fringed wings/tarsal bladder/asymmetrical mouthparts
 Economic importance of thrips-Phytophagous, predatory, insect vectors
 Total no. of species -6000 under 777 genera
 Meaning of Thysanoptera- Thysanos-fringed; Ptera-wings
 Thysanoptera order name given by –Haliday
 Typical character of thrips when you disturb it-curving its abdomen and run and
leap
 Wing venation is present in –Terebrantia and absent in -tubulifera
 Major plant virus transmitting order-Hemiptera and insect-aphids
 Thrips are the circulative and propagative manner of virus transmission
 Type of virus transmitted by thrips-tospovirus
 Number of nymphal instars-2
 Oviposition site-inside the plant tissue by ovipositor
 Resting stages –prepupa and pupa
 Symptoms-curling, crumbling, browning, wilting and shedding, tip drying, silvering
 Damage assessment by counting -25/5 wet palms; 1/leaf
 Management: cultural, biological, mechanical, chemical etc.,

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