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.

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.

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.

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. http://www.mrec.ifas.ufl.edu/lso/DOCUMENTS/Scirtothrips%20dorsalis%20NPAG%20et%20Report%20060310.pdf

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. http://mrec.ifas.ufl.edu/lso/DOCUMENTS/identification%20aid.pdf

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.

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

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

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.

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.

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.

Chilli Thrips-Adults Two adult S. dorsalis.

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.

Egg Blister

Chilli Thrips-Adults Egg Blister 

Embryo Removed from Egg Blister  Embryo 

1st Instar Larva

Chilli Thrips 1st Instar Larva Egg to 2nd Instar F° Days 60.8 17.2 68 12.0 77 7.6 86 5.8 Reference

Chilli Thrips 2nd Instar Larva F° Days 60.8 12.4 68 8.1 77 6.4 86 4.4 Reference

Chilli Thrips Pre-Pupa & Pupa F° Days 60.8 9.9 68 6.5 77 4.4 86 3.7 Pre-pupa Reference Pupa

DEVELOPMENT (DAYS) EGG TO EGG Reference

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

Scouting

Scouting

Scouting

Damage

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

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

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

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

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

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

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

Chilli Thrips - rose

Ligustrum

Pittosporum

Chilli Thrips-pepper

Chilli Thrips-pepper

Ligustrum

Ligustrum

Chilli Thrips-Indian Hawthorn

Chilli Thrips-Schefflera

Chilli Thrips-Schefflera

Chilli Thrips- Schefflera

Chilli Thrips-strawberry

Sweet Viburnum

Management Chemical See Chilli Thrips Management: Osborne & Ludwig http://www.mrec.ifas.ufl.edu/lso/THRIPS/CHILLIWEB2/chilli-doc/CHILLI%20THRIPS%20Management.pdf http://www.mrec.ifas.ufl.edu/lso/THRIPS/CHILLIWEB2/chilli-doc/CHILLI%20THRIPS%20Management.pdf

100% Reliance on Pesticides = RESISTANCE

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

ROTATE ROTATE ROTATE

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

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

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!

Management Biological

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

Amblyseius (Typhlodromips) swirskii Feeding on a Chilli thrips

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

Franklinothrips vespiformis Adult

Franklinothrips vespiformis Nymph

Management Cultural ????

Thank you!