1. Scirtothrips dorsalis
(Chilli thrips)
Joe Chamberlin
Matt Ciomperlik
Amanda Hodges
Jeff Michel
Cindy McKenzie
S. Ludwig
L.S. Osborne
Cristi Palmer
C. Regelbrugge
L. Schmale
D. Schuble
Scirtothrips dorsalis is thought to be a group of four biotypes or species that can’t be told apart except by using DNA analysis. It appears that the we are dealing with only one species in the US. This is would justify the continued effort by USDA-APHIS to prevent the introduction of the other 3 biotypes we don’t have. This is accomplished by having a zero tolerance for S. dorsalis on incoming plant materials at our ports of entry.

2. S. dorsalis
Synonyms: Chilli, Castor, Berry, Assam and Yellow Tea Thrips
Host Plants:
Over 150 host plants including banana, beans, chrysanthemum, citrus, corn, cotton, cocoa, eggplant, ficus, grape, grasses, holly, jasmine, kiwi, litchi, longan, mango, onion, peach, peanut, pepper, rose, soybean, strawberry, tea, tobacco, tomato, viburnum, etc.
There are a number of common names for this pest. The most widely used is Chilli thrips (spelled with 2 L’s). The host plant list includes over 40 different host families. The number of plants has significantly increased since the detection of this pest in the US. Please visit one of the websites given at the end of this presentation to obtain the latest information.

3. ECONOMIC IMPORTANCE Major pest of:
strawberries in Queensland, Australia
tea in Japan and Taiwan
citrus in Japan and Taiwan (Chiu et al. 1991, Tatara and Furuhushi 1992, Tschuchiya et al 1995)
cotton in the Ivory Coast (Bournier 1999)
soybeans in Indonesia (Miyazaki et al.1984)
chillies and castor bean in India
peanuts in several states in India (Mound and Palmer 1981).
Ananthakrishnan (1984) also reports damage to the following hosts: cashew, tea, chillies, cotton, tomato, mango, castor bean, tamarind, and grape.
Rose in India
Prior to being detected in the US this pest was mainly considered a serious pest of many agricultural commodities. With the exception of the reverence to being a pest of roses in India, Chilli thrips was not considered a major pest of ornamentals.

4. Is Scirtothrips dorsalis a Serious Economic Pest for the US?
Assuming an overall U.S. crop yield loss from Chilli Thrips of 5 percent the total crop value loss would equal $3.0 billion (primary hosts $583 million and secondary hosts $2.43 billion).
Assuming an overall U.S. crop yield loss from Chilli Thrips of 10 percent the total crop value loss would equal $5.98 billion (primary hosts $1.2 billion and secondary hosts $4.78 billion).
Garrett, L. (2004). Summary of Economic Analysis for Chilli Thrips.

5. Identification
Field identification of S. dorsalis is extremely difficult and often times impossible to differentiate from other thrips in the field. Adults have a pale body with dark wings and are less than 2 mm in length. Immature S. dorsalis thrips are pale in color as are the immatures of many other thrips species. Some of the distinguishing characteristics of S. dorsalis are as follows: antennae are 8-segmented with segments I–II pale, III–VIII dark; head is pale in color with three pairs of ocellar setae; one pair of ocellar setae occurring between the hind ocelli; one pair of long postocular setae behind the hind ocelli; brown antecostal line and brown area behind line in median ⅓ of abdominal tergites; abdominal sternites with brown antecostal line near anterior margin; forewings brown, paler distally; abdomen with numerous fine microtrichia.

6. Chilli Thrips-Adult
The life cycle for S. dorsalis is similar to that of western flower thrips. Female S. dorsalis insert their eggs inside plant tissue. The eggs hatch in 6–8 days. They pass through two larval stages (1st and 2nd instars) that last for 6–7 days. During this time they actively feed on the host plant. They then pass through a prepupal (~24 h) and pupal stages (2–3 days) during which time they do not feed. They can complete their life cycle in 14–20 days. The thrips female oviposit 60 to 200 eggs in her lifetime.

7. Male and Female (larger)
Chilli Thrips-Adults
Male and Female (larger)

8. Thrips-Adults Western Flower thrips Chilli thrips
In this slide you can see the relative size of an adult chilli (left) thrips compared to an adult flower thrips (right).
Chilli thrips

9. Western Flower Thrips Adult
Note the heavy dark hairs or setae at the end of this flower thrips abdomen. These setae are not as distinct or easily seen on Chilli thrips adults.

10. Chilli Thrips-Adult (recently emerged)
In this slide you can see the dark transverse bands across the abdomen of an adult. The light color of the wings in this adult is unusal. It may be an individula that has just molted and hasn’t fully developed its adult coloration.

11. Chilli Thrips-Adult
In this slide you can see the dark transverse bands across the abdomen of an adult. This is a more typical photo of an adult because you can also see the dark wings that make it appear as if the adult has a dark stripe down its back.

12. Chilli Thrips-Adults
Two adult S. dorsalis.

13. Chilli Thrips (mixed stages)
2nd instar
1st instar
This slide shows a number of thrips adults. There is a first instar larva near the center of the slide and a 2nd instar larva near the top edge.

14. Egg Blister

15. Chilli Thrips-Adults
Egg Blister 

16. Embryo Removed from Egg Blister
Embryo 

17. 1st Instar Larva

18. Chilli Thrips 1st Instar Larva
Egg to 2nd Instar
F° Days
Reference

19. Chilli Thrips 2nd Instar Larva
F° Days
Reference

20. Chilli Thrips Pre-Pupa & Pupa
F° Days
77 4.4
86 3.7
Pre-pupa
Reference
Pupa

21. DEVELOPMENT (DAYS) EGG TO EGG
Reference

22. Over Wintering of Pupae
Grapes
64.4% in liter
16.2% in branch zone
12.5% in soil
6.9% leaf zone
Reference
Okada & Kudo 1982

23. Scouting

24. Scouting

25. Scouting

26. Damage

27. Hosts Acanthaceae Strobilanthes dyerianus Mast.
Araliaceae Hedera helix L.
Berberidaceae Mahonia bealei
Caprifoliaceae Viburnum suspensum
Combretaceae
Conocarpus erectus
Laguncularia racemosa (L.) Gaertn. f.
Compositae Gerbera jamesonii H. Bolus ex Hook. f.
Ericaceae Rhododendron spp.
Euphorbiaceae Ricinus communis
Illiciaceae Illicium floridanum Ellis
Moraceae Ficus elastica
Table 4: Number of FDACS/DPI confirmed and unconfirmed botanical families and their genera and
species positive for Scirtothrips dorsalis in Florida as of September 2006.
Confirmed botanical families positive for S. dorsalis in Florida as of September 2006
Plant Family Genus species: Families = 16 Species = 24

28. Hosts Oleaceae Jasminum sambac (L.) Ait. Ligustrum japonicum Thunb.
Pittosporaceae Pittosporum tobira (Thunb.) Ait. f.
Rosaceae
Raphiolepsis indica
Rhaphiolepis umbellata (Thunb.) Mak.
Rosa sp.
Rubiaceae
Gardenia jasminoides
Richardia brasiliensis Gomes
Table 4: Number of FDACS/DPI confirmed and unconfirmed botanical families and their genera and
species positive for Scirtothrips dorsalis in Florida as of September 2006.
Confirmed botanical families positive for S. dorsalis in Florida as of September 2006
Plant Family Genus speciesFamilies = 16 Species = 24

29. Hosts Rutaceae Citrus sp. Murraya paniculata (L.) Jack Solanaceae
Capsicum annuum L.
Capsicum frutescens L.
Capsicum sp.
Table 4: Number of FDACS/DPI confirmed and unconfirmed botanical families and their genera and
species positive for Scirtothrips dorsalis in Florida as of September 2006.
Confirmed botanical families positive for S. dorsalis in Florida as of September 2006: Families = 16 Species = 24
Plant Family Genus species

30. Hosts Amaranthaceae Celosia argentea L. Araceae Philodendron sp.
Araliaceae Schefflera arboricola (Hayata) Merrill
Balsaminaceae Impatiens walleriana Hook. f.
Compositae Coreopsis sp.
Compositae Zinnia sp.
Euphorbiaceae Poinsettia pulcherrima Graham
Gentianaceae Eustoma grandiflorum (Raf.) Shinn.
Geraniaceae Pelargonium x hortorum Bailey
Hamamelidaceae Loropetalum chinense (R. Br.) Oliver
Unconfirmed botanical families positive for S. dorsalis in Florida as of September 2006: Families = 19 Species = 22

31. Hosts Labiatae Plectranthus scutellarioides (L.) R. Br. Salvia sp.
Leguminosae Phaseolus vulgaris L.
Lythraceae Cuphea sp.
Marantaceae Stromanthe sanguinea (Hook.) Sonder
Onagraceae Gaura lindheimeri
Rubiaceae Pentas lanceolata (Forssk.) Deflers
Scrophulariaceae Antirrhinum majus L.
Solanaceae Petunia sp.
Verbenaceae
Duranta erecta
Glandularia x hybrida (Grön. & Rüm.) Neson & Pruski
Unconfirmed botanical families positive for S. dorsalis in Florida as of September 2006: Families = 19 Species = 22

32. Damaged Flower Bud and Leaves
Photos: L. Osborne, UF-IFAS
Mannion

33. Comparison of damaged and normal leaf
Normal new growth
Damaged new growth
Photos: L. Osborne, UF-IFAS
Mannion

34. Chilli Thrips - rose

35. Ligustrum

36. Pittosporum

37. Chilli Thrips-pepper

38. Chilli Thrips-pepper

39. Ligustrum

40. Ligustrum

41. Chilli Thrips-Indian Hawthorn

42. Chilli Thrips-Schefflera

43. Chilli Thrips-Schefflera

44. Chilli Thrips- Schefflera

45. Chilli Thrips-strawberry

46. Sweet Viburnum

47. Management Chemical See Chilli Thrips Management: Osborne & Ludwig

48. 100% Reliance on Pesticides =
RESISTANCE

49. What Can Growers Do?
Pay attention to information distributed by SAF, the propagators, media, pesticide companies and/or University and ARS scientists.
Implement INSECTICIDE RESISTANCE MANAGEMENT PROGRAMS
IRM

50. ROTATE
ROTATE
ROTATE

51. Effective Products 7 Different Modes of Action
Table based on data from:
Ciomperlik
Ludwig
Osborne
Seal
Effective Products 7 Different Modes of Action
Acephate Foliar N, G, L
Acetamiprid Foliar N, G, L
Clothianidin Foliar N, G, L
Dinotefuran Foliar N, G, L
Imidacloprid Foliar N, G, L
Thiamethoxam Foliar N, G, L
Spinosad Foliar N, G, L
Abamectin Foliar N, G, L
Flonicamid Foliar G
Chlorfenapyr Foliar G
Pyridalyl Foliar G
N=Nursery
G=Greenhouse
L=Landscape
Compounds in Yellow = the same MOA

52. Use of Same Mode of Action Pesticide and limited others
RISK OF RESISTANCE
MANAGEMENT OPTION
LOW
MEDIUM
HIGH
Pesticide Rotation
> 2 Modes
2 Modes
1 Mode
Use of Same Mode of Action
Once
More than once
Many times
Infestation Level
Low
Medium
High
Control in Last 3 Cycles
Good
Declining
Poor
IPM System
All Tactics
Pesticide and limited others
Pesticide only

53. PLAN Identify All Pesticides Registered for the Pest and Crop
Determine Plant Safety
Determine Labeled Frequency
Determine Other Use Restrictions
Organize Treatments (MOA…)
Don’t Forget Other Pests!

54. Management Biological

55. Why Biological Control?
To help manage pesticide resistance in populations of Western flower thrips.
Chilli Thrips was attacking basil, mint, and peppers in organic production systems.
Thrips control impacted implementation of IPM programs in many ornamental crop systems.
Chemical control in the landscape is
NOT SUSTAINABLE

56. Amblyseius (Typhlodromips) swirskii Feeding on a Chilli thrips

57. Control of Chilli Thrips Chilly Chili Pepper
Study 1
N=20
5 plants/Unit
4 Units/treatment

58. Franklinothrips vespiformis
Adult

59. Franklinothrips vespiformis
Nymph

60. Management Cultural ????

62. Thank you!