Control of thrips without pesticides: dream or reality?

Sarah Jandricic, Floriculture Extension Specialist, OMAF and

Graeme Murphy, Grenhouse IPM Specilaist, BioLogical Control Solutions

DAMAGE

~ $15 M

per year in

Georgia

PLANT VIRUSES

Impatiens necrotic spot – severe crop losses

LIFE CYCLE

12 days in hot weather

NON-SUSCEPTIBLE STAGES!

HISTORY OF AREA • Late 1980’s

• Calendar sprays • Weekly in winter

• 2x a week in summer

• Little monitoring, IPM, or Biological control

NOW (i.e. since 2007):

• IPM – standard • Monitoring – routine

• Screening

• Mass trapping

• Biological control – 80-90% of growers

PESTICIDE RESISTANCE - THRIPS • Spinosad – registered in Canada in 2006

• Poor control in 6-12 mo • Pesticide residues on cuttings?

• Widespread breakdown in efficacy by 2008

• 2007: thrips became driver for biocontrol adoption

What tools do we have?

Biocontrol -

Foliage

Amblyseius cucumeris

Biocontrol -

Foliage AMBLYLINE, THRIPEX, etc

What’s in a sachet??

Entomopathogenic Fungi

Biocontrol -

Foliage BotaniGard, Naturalis, etc

Orius insidiosus

Biocontrol -

Foliage Boi-Orius, Thripor, Orius-

System, etc.

NON-PESTICIDE SUSCEPTIBLE STAGES!

NON-PESTICIDE SUSCEPTIBLE STAGES!

Target for

biological

control!

Amblyseius cucumeris

Orius insidiosus

Fungi e.g. BotaniGard

Biocontrol -

Foliage

Biocontrol -

Soil

Hypoaspis mites.

Biocontrol -

Soil

Hypoline-M, Entomite-M,

Hypoaspis

Biocontrol -

Soil Atheta, Rove Beetle,

StaphyLine

Atheta/Dalotia coriaria

Biocontrol -

Soil Entonem, Nemysis

Nematodes: Steinernema feltiae

0

20

40

60

80

100

120

140

160

180

200

t = 0 t = 2 weeks t = 4 weeks t = 6 weeks t = 8 weeks

Growing media + nematode

Growing media + Plants +nematode

Me

an

nu

mb

er

of n

em

ato

de

/g o

f d

ry s

oil The difference becomes wider

as the plants grow bigger

Nematode

population drops

dramatically as

the application

stops

Application stopped at week 6

Nematodes – Steinernema feltiae

Amblyseius cucumeris Hypoaspis / Stratiolaelaps spp.

Orius insidiosus Nematodes: Steinernema feltiae

Fungi e.g. BotaniGard

Biocontrol -

Foliage

Biocontrol -

Soil

Atheta/Dalotia coriaria

Combining bios so there’s no escape!

Western flower thrips

Mums as a case study: Integrate biocontrol throughout the production system

Research plant risks Choose resistant plants

“Use” susceptible plants Reduce fertilizer

Propagation

Use Mite sachets Microbials Nematodes

Broadcast Cucumeris Microbials Nematodes Hypoaspis

Atheta

Planning Production Finishing

Swirskii sachets Microbials

Amblyseius cucumeris Hypoaspis / Stratiolaelaps spp.

Orius insidiosus Nematodes: Steinernema feltiae

Fungi e.g. BotaniGard

Biocontrol -

Foliage

Companion

Strategies Biocontrol -

Soil

Atheta/Dalotia coriaria

?

?

?

COMPANION STRATEGIES

1. Trap plants • Flowering yellow mums

• Highly susceptible varieties: Vyron, Chesapeake

• Use with: • Other mum varieties

• Vegetative / foliage crops

• herbs

COMPANION STRATEGIES

2. Mass trapping with sticky tape

• Used in biocontrol programs based on non-flying natural enemies

0

25

50

75

100

125

150

175

200

225

250

275

1

Mea

n B

iwee

kly

Th

rip

s C

ou

nts

/

2 f

eet

of

tap

e

Type of Sticky Tape

a

b ab

b b b

–E.g. Pot Mum Production

1 COMPARTMENT= 1500 Feet of Tape

June 1-Aug 15:

= 647, 872 thrips/

compartment removed!

The Power of Sticky Tape!

SEE THE DETAILS: GREENHOUSE CANADA WEBINAR And

GREENHOUSEIPM.ORG

COMPANION STRATEGIES

3. Dipping cuttings – starting clean • Most effective treatments on mums for thrips:

• Beauveria

• Horticultural oil at 5 ml/L for 1 min, then rinsed

SUCCESSFUL BIOCONTROL OF A DIFFICULT PEST • Take whole production system into

account

• Susceptible stages/varieties targeted

• Uses companion strategies to improve results