Take Back the Greenhouse

Learning how to control pests with biocontrols

Paul Koole

Technical Team Coordinator

North America

Biocontrol of thrips

• Knowledge is Key

• Think about what crops you want to

grow – possible pest pressure

– Extra focus on ‘Problem children’

• Control options:

– BCA’s

– Time of year

– Cultural practices

– Pesticides (compatibility w/BCA’s)

6/18/2018

Aphid behaviour in the greenhouse

• Arrival and adaptation to the plant

– Winged / alate from conducting

exploratory probe into phloem

• Inject fluids into the plant and

manipulate host

• Explosive reproduction

– Asexual (no males present)

– Viviparous

• Developing alates and migration

to other plants** Influenced by multiple factors

18 juni 2018

Problematic species

• Limited N° of problem species

• Despite polymorphism, recognizing species

“easier” than expected

• Specific problems not only caused by the

species itself, but also by presence of

bacteria or fungi

– Facultative symbionts:– Reproduction

– Heat stress

– Plant manipulation

– Resistance to parasitoids18 juni 2018

Identification

Importance of identification:• When using BCA’s → parasitoids work on specific

species!

• When using traditional control → some pesticides and or

application technique work better then others depending

on species!

• Some aphid species cause more damage then others

(e.g. Foxglove aphid)

“common mistakes”• Color is not a good indicator!

• Aphids have a very wide range of host plants → plant spp

does not tell what aphid spp you have

18/06/2018

Based on morphological characteristics:

• Abdomen:

- shape and color patern

- dorsal lines and stripes

• Wings:

- vain pattern

• Head:

- shape, color and position of tubercles

- size, color and position antenna

• Cornicle:

- shape, color and size

• Cauda:

- shape, color and size

Identification

Aphid anatonomy

18/06/2018

Aphid identification

18/06/2018

Documents

Blackman & Eastop (2000). Aphids on the world

crops. An identification guide. Wiley, Chichester,

UK.

Available at http://www.aphidsonworldsplants.info

18/06/2018

Aphis gossypii

A.K.A. Cotton or Melon Aphid

• Relatively small, size varies (0,9 –

1,8 mm);

• Black cornicles

• Red eyes

• Relatively short antennae

• Colour: depends on food source,

temperature and population

density

18 juni 2018

Myzus persicae subsp. Persicae

Myzus persicae subsp. nicotianae

• A.K.A. Green peach aphid &

Tobacco aphid

• Relatively small, size varies (1,2-2,1 mm)

• Colour varies from green to pink;

• Tobacco aphid is always pink or red (but not a

distinctive characteristic)

• Antenna same length or slightly shorter then

body

• Medium size cornicles

• Red morph* behaviour is different:

– more tolerant to higher temperatures;

– less suceptible to pesticides;

– Difference in predator preference

*Due to adoption of a gene from a fungi

Macrosiphum euphorbiae

A.K.A. Potato aphid

• Larger aphid species (1,7 – 3,6

mm)

• Long cornicles with darker tips &

long legs

• Antenna very long, longer than

body

• Dark, longitudinal stripe on dorsal

surface

• Yellowish, bright green or pink

• Easily disturbed, which works as a

defense mechanism → aphids

drop when plant is touched18/06/2018

Aulacorthum solani

A.K.A. Foxglove aphid /

Glasshouse potato aphid

• Larger aphid species (1,8-3,0 mm)

• Glossy yellowish-green to brownish

green

• Medium - long cornicles

• Dark green patches around the cornicles

• Antennae exceeds length of the body

marked by a number of dark bands

• Black tips on legs

• When piercing leaves or fruits (SP),

excretes toxic substance which causes

deformation → plant destructive!

18/06/2018

Parasitoids

Aphidius colemani Parasitizes

• Green peach aphid (myzus persicae)

• Cotton aphid (Aphis gossypii)

• Potato aphid (Macrosiphum euphorbiae)

• Foxglove aphid (Aulacorthum solani)

• Strawberry aphid (Aphis forbesi)

• Blackcurrant aphid (Aphis schneideri)

• Small bramble aphid (Aphis ruborum)

• Raspberry aphid (Aphis idaei)

Banker system(s)

• Oleander aphid (Aphis nerii)

• Bird cherry-oat aphid (Rhopalosiphum

padi)

18 juni 2018

Strengths• Quick

• high search capacity

• High oviposition (approx. 80-100/day)

• Majority of eggs laid first 3 days

• Excellent searching behaviour at low aphid

densities

Weaknesses• Sensitive to hyper-parasitism

Parasitoids

Aphidius ervi

18 juni 2018

Parasitizes• Potato aphid (Macrosiphum euphorbiae)

• Foxglove aphid (Aulacorthum solani)

• Green peach aphid (Myzus persicae)

• Rose aphid (Macrosiphum rosae)

• Large raspberry aphid (Amphorophora idaei)

• Blueberry aphid (Ericaphis fimbriata)

Banker system(s)• English grain aphid (Sitobion avenae)

Strengths• Quick (faster than A. abdominalis)

• high search capacity

• Aggressive!

• High oviposition (approx. 80-100/day)

• Majority of eggs laid first 3 days

• Active search from 10C°

Weaknesses• Sensitive to hyper-parasitism

Parasitizes:

• Green peach aphid (myzus

persicae)

• Cotton aphid (Aphis gossypii)

• Potato aphid (Macrosiphum

euphorbiae)

• Foxglove aphid (Aulacorthum solani)

Banker system(s):

• Oleander aphid (Aphis nerii)

• Bird cherry-oat aphid

(Rhopalosiphum padi)

Parasitoids

Aphidius matricariae

18 juni 2018

Strengths• Quick start up, faster than A. colemani

• high search capacity

• High oviposition (approx. 80-100/day)

• Less sensitive to hyper-parasitism

Parasitoids

Aphelinus abdominalis Parasitizes

• Green peach aphid (myzus persicae)

• Cotton aphid (Aphis gossypii)

• Potato aphid (Macrosiphum euphorbiae)

• Foxglove aphid (Aulacorthum solani)

• Strawberry aphid (Chaetosiphon

fragaefolii)

• Blueberry aphid (Ericaphis fimbriata)

Banker system(s)

• English grain aphid (Sitobion avenae)

18 juni 2018

Strengths• Long life span: 30 day – 2 months

• Substantial contribution by hostfeeding

Aphidoletes aphidimyza

Strengths

• Excellent searching behaviour /very mobile

• Deposit eggs where needed (e.g.hotspots)

• Larva kill up to 80 aphids per day

• Makes way for parasitoids

Oddities

• Mating first night after hatching

• Pupae drought prone

• Presence of honeydew strong influence on ovi-position and longevity

of the adult

Diet

• Adults → nectar and pollen

• Larvae → all aphid species

• 10 -100 aphids per gall midge

50% during last larval stage

Cycle:

15°C : 4,5 weeks

20°C: 3 weeks

25°C: 2 weeks

Longevity:

7-10 days

Conditions:

> 16°C, 80% RH

Aphidoletes aphidimyza

Aphidoletes aphidimyza

18/06/2018

Strengths

• Hotspot “cleaner” (but not completely…)

• Reproduction inside the greenhouse

• Direct “In action”

Weaknesses:

• Relatively expensive

• Limited search behaviour

• Adults are able to leave the greenhouse

Diet:

• Aphids

• 100 prey/ dag

• 80% total consumption during last 2 larval stages

Adalia bipunctata

Cycle:

Egg - larve: 1 week

Larvae - pupae: 3 weeks

Pupae - adult: 1 week

Ovi-position:

In groups of 10-40 eggs

500 eggs in total over 30 days

Longevity: 50 days

Conditions: 24-28°C, 70-

80%RV

Adalia bipunctata

Chrysopa carnea(lacewing)

Strengths

• Relatively cheap

• Direct “in action”

• Tolerant to low temperatures (< 0°C) if daily

temperature is higher

Weaknesses

• Installation difficult

• Cannibalistic

Diet

• Adults → nectar and pollen

• Larvae → polyphage, prefers aphid species

• Consumes 300-500 aphids in total

Parasites & Predators

Parasitoids vs Predators

Parasitoids

• Generally better searchers → find that first aphid!

• Use host to lay egg inside and reproduce → life depends on it!

(specialist)

• Are often more specific to one or a few species of host

• Used as a “first line of defense”, in combination with banker plants.

Predators

• Better/faster in cleaning up hot spots

• Eat or such dry their prey and are often very varocious (true killers)

• Develop better in hotspots

• Are not very species specific → are not picky eaters!

18/06/2018

Biobest strategy

Severity scales of aphid infestationPreventative

• Free of aphids / no detection

Semi-curative

• Expect first aphids / first detected

• Distributed over the whole plant

Curative

• Aphids present

• Mainly in the head bigger colonies

High curative

• Multiple, big colonies

• Honeydew production, alate forms

1

4

3

2

2

Biobest strategy

Preventative

Parasitoids (with/without banker plants)

• Aphelinus abdominalis

• Aphidius spp.

Semi-curative

Parasitoids (with/without banker plants)

• Aphelinus abdominalis

• Aphidius spp.

Curative

Gall midge / searchers

• Aphidoletes aphidimyza

• (Episyrphus balteatus)

High curative

Voracious predators / less searchers

• Adalia bipunctata

• Chrysoperla carnea

More

“organic”

More

“conventional”

Tools

• Banker systems:

– Parasitoid bankers

– predator bankers

• Induced resistance

• Feeding stations

– Artificial

– “Nectar”-bankers

• Feeding spray

Barley banker plants

18/06/2018

Feeding stations or spray

Plants• Allisum

• Artemisia

• Crambe cardifolia

• Polygonum

• Artifical flowers (experimental)

• Sprays (experimental)

Goal• Increase fecundity and longevity of BCA’s

Pitfalls

• “Balance swings”

• Aphid reproduction

• Hyper-parasitism

• Intraguild

• Impatience

• ........

Balance swings

Aphid reproduction

• Mainly in organic

production

• Certain periods of the

year, a boost of aphid

population is to be

expected

• Anticipate with different

BCA’s in advance

• Meticulous monitoring of

aphids AND beneficials!

Intraguild

• Swirskii → Aphidoletes

eggs

• Coenosia adults→

parasitic wasps

• Coenosia larvae →

Aphidoletes?

• Macrolophus →

Aphidoletes/Episyrphus

larvae

• ...

18/06/2018

Aphid hyper parasitoïds…

The enemy of

my enemy is

my friend?

Knowing them better…Tritrophic relations

Hyperparasitoids= generalists

PrimaryParasitoids

= more specific

Hosts (Aphids)

So there is not an existing list of hyperparasitoid per parasitoid species,

because that will depend on too many parameters:

crop, aphid species, presence of nectar, location, climate, etc…

Source: Mustata & Mustata

Knowing them better…Endoparasites

Young Colemani larva(remains alive

for a while)

Aphid not yet mummified(recently parasitized by

colemani)

Common species: Alloxysta sp, Lytoxysta, Phanaeoglyphis sp,

Tetrastichus

They have more specific hosts

Some of them can parasitize mummies too

Knowing them better…Endoparasites

Alloxysta victrix

Knowing them better…Endoparasites

A. colemani

Knowing them better…Endoparasites

18 juni 2018

Knowing them better…Chronology, their weakness

Pa

rasi

toid

En

do

Ect

o

HatchingPrimary

Parasitism Mummy

Secondary parasitism

7-8 days 5-7 days

2-3 d 14-21

days

Hatching

7-10 days

Total

13-16 d

16-24 d

14-21 days 21-31 d

• Hyper parasitoids appear after a certain density of mummies.

• Primary parasitoids can escape in presence of hyper

parasitoids

• Presence of plant nectar, or honey dew can increase

attraction and help development of hyper parasitoids (better

fecundity + longevity)

18/06/2018

Knowing them better…Some elements from literature

Strategy to avoid hyper parasitoids

• Check hyper parasitism rate in a regular

base (mummies or adults)

• Try to keep aphid density low (prefer

preventive strategy releases)

• Bankerplant management!

Be careful with banker plants!!

• Check bankers for hyper parasites

• Don’t let them fade out in the greenhouse ➢ (not longer than 4 weeks and 6 weeks max!)

• If possible, introduce the banker plants already parasitized

in a cage (protected from hypers)

Strategy to avoid hyper parasitoids

Banker scheme to avoid hyper

parasitoids

Egg larva larva adult adult adult adult adult adult

adult adult adult

(Sting)egg larva pupa (mummy)

adult

(Sting)egg larva pupa (mummy) adult

Protected sting cage/roomCarry off bankers

(close-cropped)

before hatching of

hyperparasites!

Variation in terms of BCA’s: – Use predators like Aphidoletes, Chrysopa… they kill also parasitized

+ hyper parasitized aphids!

– Use parasitoid species less susceptible to be parasitized

(Matricariae / Aphelinus?)

18/06/2018

Strategy to avoid hyper parasitoids

6/18/2018

THRIPS

June 18, 2018

Thrips

Different thrips species found in the industry:

• Frankliniella occidentalis (Western Flower Thrips –

most common)

• Franklinella intonsa (European Flower Thrips)

• Franklinella tritici (Eastern Flower Thrips)

• Thrips tabacii (Onion Thrips)

• Echinothrips americanus (becoming more common)

• Scirtothrips dorsalis (Chili Thrips)

Very important to get proper ID if you are unsure!

Thrips ID

The enemy:• Frankliniella occidentallis (Western flower thrips)

6/18/2018

Thrips ID

Echinothrips americanus

6/18/2018

Thrips life cycle

6/18/2018

Adult

egg

Larvae 1

Larvae2

pupae

June 18, 2018

3 4

Thrips – WFT development

68F 6 days 3 + 3 Days 6 days up to 60 days

86F 3 days 1.5 + 1.5 Days 3 days 20 - 40 days

• Fecundity in vegetative stage of crop → 4 – 5 eggs / female

• Fecundity when pollen available → 15 eggs per female

Egg(In leaf tissue)

Larva

1 & 2(on plant → exposed)

Pupa(in soil)

Adult(on plant → exposed)

June 18, 2018

3 4

Thrips – WFT development

68F 6 days 3 + 3 Days 6 days up to 60 days

86F 3 days 1.5 + 1.5 Days 3 days 20 - 40 days

Amblyseius spp Hypoaspis miles Orius insidiosus

Orius insidiosus Atheta coriaria Steinernema f.

Steinernema f (40% effective)

• Fecundity in vegetative stage of crop → 4 – 5 eggs / female

• Fecundity when pollen available → 15 eggs per female

Egg(In leaf tissue)

Larva

1 & 2(on plant → exposed)

Pupae(in soil)

Adult(on plant → exposed)

Thrips development time

6/18/2018

One female

thrips

30 days 30 days

Development of thrips in 60 days (@ 68°F)

± 90 thrips

± 5800 thrips

Thrips

Benefical Insects

• Amblyseius cucumeris vs Amblyseius Swirskii➢ Bulk or Sachets???

➢ Mini Sachets, Regular Sachets, Sachets on a stake

• Degenerans➢ w/Nutrimite

• Orius➢ Banker Plants

➢ Nutricards

• Nematodes➢ Steinernema f.

• Hypoaspis

• Atheta

June 18, 2018

Biological Control of Thrips

Amblyseius cucumeris

June 18, 2018

Biological Control of Thrips

Amblyseius swirskii

Biological Control of Thrips

6/18/2018

A.degenerans

June 18, 2018

Biological Control of Thrips

Hypoaspis spp.

June 18, 2018

Biological Control of Thrips

Atheta

June 18, 2018

Biological Control of Thrips

Orius insidiosus (can be in combination with banker

plants → pepper and/or allysum plants)

Orius feeds on larval and adult thrips

6/18/2018

Nutricard: enhances

introductions of Orius;

gives extra protein,

just like in production.

Which nematode is effective for thrips??

Steinernema feltiae• active searcher

• wetting agent recommended

• penetrates larvae

• most activity b/t 15 -20C

• release of symbiotic bacteria in reproduction

• kills host in 48hrs

Controls:

• fungus gnat larvae

• Western Flower Thrips larvae & adults

- NOT: Echinothrips, Chilli thrips(Scirtothrip dorsalis),

Banded Grhs thrips(Hercinothrips femora)

6/18/2018

June 18, 2018

Biological Control of Thrips

Steinernema feltiae (R. Buitenhuis AAFC – Harrow)

Thrips larva

Steinernemafeltiae coming

out of larva

Adult thrips

Steinernemafeltiae inside adult thrips

Nematodes ‘swimming’

6/18/2018

No Hitch hikers??

• Thank you to Wendy Romero, U. of Guelph,

Ontario, Canada and Flowers Canada!

6/18/2018

“Clean” cuttings & plugs

Wendy Romero’s work at U of Guelph (Hitchhikers on mum cuttings):

• Followed incoming cuttings at potted mum grower from supplier for 8 months (January to August 2009)

• Sampled every 2 weeks

• 5 varieties

• Cuttings where washed out in Ethanol (Adults and Larva)

• Not one sample had zero thrips

• Number of thrips were as high as 3 Adult thrips per cutting and even more L1 and L2

• This is visually almost not detectable!

6/18/2018

“Clean” cuttings & plugs

6/18/2018

Average number of adults and immature per sample per cultivar

June 18, 2018

Controlling pests in propagation

Incoming plant material and own propagation:

• Use nematodes and /or botanigard to minimize problems

getting foothold in propagation

• Pro-actively → dip / submerge rooted or unrooted

cuttings in a nematode solution (Steinernema spp) and /

or Beauveria bassiana (BotaniGard)

• Be very consistent with all the propagation → this is the

main part of the overall program!

• As soon as mist is reduced or off → start with other

BCA’s

Dipping & sprenching

June 18, 2018

Application: dipping

6/18/2018

Application: sprenching

Planting line water ‘tunnel’

Application: tips

• Think like a nematode: it’s alive!! ; naturally occurring in

the soil; it needs water/moisture to ‘swim’/move around

• UV light kills

• Rates: How often; When to apply, how much per

application

• Use low of pressure as possible while still getting good

‘mist’; from 75psi – 300psi recommended??; pump or

nozzle?

• Remove filters: <1mm diameter

• Nozzles: should be >1mm

6/18/2018

Application: tips

• Avoid sharp differences is water temperature vs.

nematodes when mixing

• Cooler water better – more capacity to hold oxygen

• Use entire package: not necessarily mixed

homogenously

• Premix larger volumes of nematodes with water in

separate bucket; min of 10L

• Ensure solution remains agitated (bubbler)

throughout application; nematodes settle 1cm/min

• Apply immediately, do not store solution

6/18/2018

June 18, 2018

BCA’s for thrips

Cucumeris sachets in propagation

6/18/2018

BCA’s in action

Amblyseius cucumeris mini sachets

on baskets

Biocontrol innovation

6/18/2018

Nutrimite:

June 18, 2018

Bio-control in Action

Pepper plants to establish and support Orius:

June 18, 2018

Bio-control in Action

Plants with Orius also used outside:

Quick review

• Thrips population can and usually

starts early in crop cycle

• Know & understand your pest biology

• Know & understand possible pest

issues in your crops

• Start BCA program ASAP

• Use BCA’s to manage chemical

resistance

6/18/2018