biological control at jeffery ’s greenhouses jeffery ’s ... · aphid control at our greenhouse...

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Biological Control at Biological Control at

JefferyJeffery’’s Greenhouses Inc.s Greenhouses Inc.

JefferyJeffery’’s Greenhousess Greenhouses

Greenhouse Operation in St Catharines, ON

3rd Generation family business

In operation approximately 65 years

Approximately 8 hectares under cover at 2 locations

About 2 hectares outdoor production

Bedding plants and perennials for spring and summer

Cyclamen, Garden Mums, and Poinsettia for fall/winter

All but Cyclamen exclusively shipped to Big Box stores

Market covers much of Ontario and Western New York

JefferyJeffery’’s s

GreenhousesGreenhouses


Most Plant material propagated in-house

�Better success with pest control (biologicals)

�Better overall crop control

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Biocontrol at Jeffery’s Greenhouses since 2005

�Personal experience with biocontrol since 1988

�Whitefly control failure in 2004 Poinsettias was trigger

�Duponchelia ‘crisis’ amalgamated commitment of

company management to biological control

�Reduced use of synthetic pesticides by more than 95%

What Makes ModernWhat Makes Modern

Biological Control Biological Control

So Complex ?So Complex ?

And What Can We Do About It ?And What Can We Do About It ?

Full Circle Full Circle ……

“If you would have asked any American

Farmer in the early 1890’s what is the best

way to control insects, they would have

said ‘biological control’…”

James MacWilliams – Yale University

Author of “American Pests: The Losing War on Insects from Colonial Times to DDT”

Listen to the podcast @ http://wordforword.publicradio.org/programs/2008/07/18/

Pest Control Pest Control -- The DilemmaThe Dilemma

• With each new generation of pesticides:

�we have improved pest control tools - temporarily

�pest control costs/efforts decrease - temporarily

� it becomes comparatively more expensive to

apply alternative pest control strategies

�we can not afford NOT to use the new pesticides

�we return to the same dilemma each time when

the new pesticides begin to ‘wear off’

• the more successful we become in controlling

pests with a given tool - the more dependent

we become on the success of this tool

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Why Biological Control ?Why Biological Control ?

Biological Control

�Not a choice based on ethics

�Not (merely) an issue of economics

�But a necessity due to evolution of pests / farming

We are using biological control

not as the result of conscious choice, but

because we have no effective alternative

Pest Control Pest Control -- The DilemmaThe Dilemma

� Growers can not afford Pest Control failures

� But at the same time, “Good” Pest Control:

�must be simple – not require detailed know-how

�must be cheap - it is a “non-productive” input cost

� “just has to work” - failure = economic disaster

� This is not realistic

�We had a few years of good/easy/cheap control

�versus 4000 years of “documented plagues”

� We have to re-invent pest control

No Easy Way to go No Easy Way to go ‘‘Back To The FutureBack To The Future””

% of American population working in farming

69%

49%

38%

27%18%

7% 2%

Major Pest Control Developments

We need new paradigms in Pest ControlWe need new paradigms in Pest Control

� Pest Control can no longer be easy,

AND reliable

AND cheap

� New Pest Control

� is complex and information intensive

(means: we all have a to learn a lot … fast)

� is not cheap (mostly preventative cost)

� is not guaranteed to be succesful

(requires “leap of faith” for the farmer)

� is inevitable (consequence of evolution/nature)

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Pest Control vs. Pest ManagementPest Control vs. Pest Management

• We can no longer focus on:

�responsive control vs. preventative control

�chemical control vs. biological control

�cost comparisons between different methods

• Instead, we need to focus on:

� anticipation of potential new pest/disease threats

� concurrent use of multiple methods

� reduced cost through understanding of

interactions between pests, crops, and controls

� factor ‘insurance premiums’ into pest control cost

We have learnedWe have learned

Biological Control does not merely mean

�Replacing chemical control products

�with beneficial insects or mites

Instead

� it requires us to look at the greenhouse as a

complex eco system

� controlling pests becomes synonymous with

managing this eco-system

� rather than trying to eliminate individual pests on

individual crops

Biological Control is a System ApproachBiological Control is a System Approach

� Biological Control is a Systems Approach

� Systemic approach to Pest Control

�creates systemic problems

�with ripple effects through the entire system

� requires knowledge of all parts of the system

�or a lot of experience in operating the system

�Deals not just with individual pests,

�but with the complexity of entire system

In Complex SystemsIn Complex SystemsYou cannot treat individual parameters as entities

A change to one parameter of the system

can create changes to all other parameters of the system

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You cannot treat individual parameters as entities

A change to one parameter of the system

can create changes to all other parameters of the system

In Complex SystemsIn Complex Systems

Aphids

Aphidius

Whitefly

Encarsia

More

Fuchsia

Less

Petunia

Thrips

Amblyseius

Example: AphidsExample: Aphids

� Aphid control at our greenhouse

� In spring of 2006 we failed to control peach and

foxglove aphids with pesticides

�Result: in spring of 2007 first attempt at biocontrol

of all aphids in bedding plants

�Need to control Thrips with biologicals because all

effective pesticides disrupt aphid beneficials

�As a result, we developed effective Thrips control

�while biological control of Aphids in bedding plants

is still very difficult

AphidsAphids -- PesticidesPesticides

� In bedding plants

�Aphids feed on the petals of open flowers

�No stomates on petals => No Xylem flow to petals

�Not enough systemic insecticides from rootzone

drench (e.g. Imidacloprid) transported to flowers

�Spray Applications of systemic aphidicides very

disruptive to beneficials used for other pests

�Pymetrozine (Endeavor) currently the only option

�Pymetrozine not effective at cool temperatures

�Some tolerance/resistance to Pymetrozine ?

Systemic Pesticides wonSystemic Pesticides won’’t reach these Aphidst reach these Aphids

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Peach Aphids Peach Aphids -- MyzusMyzus persicaepersicae

� Aphidius colemanii

�gave good control at higher temperature (>18°)

�but most bedding plants grown cooler

�at cooler temperatures, control 'lags' somewhat

behind aphid development

�Colemanii does not seek out small colonies

�good control is eventually achieved

�but resulting 'mummy' colonies are unsightly

�created problems in garden centers



� Better control with Aphidius matricariae, which

have been reared on peach aphids

�we apply weekly at first observation of aphids

�parastoid appears to be conditioned to search for

peach aphids before parasitizing other species

�better results with seeking out and parasitizing

even small colonies of aphids

� these insects are shipped as life adults

�short lifespan means rapid distribution is critical

Potato Aphid Potato Aphid -- MacrosiphumMacrosiphum euphorbiaeeuphorbiae

� Occasionally a pest in ornamentals

�primarily on Gerbera, Peppers, Petunia

� We avoid spot sprays for Potato Aphids

�we did not observe enough damage potential

�effect of spot sprays on other controls in the

system is more severe than damage from aphid

• Relatively easy to control with

�Aphidius ervi in winter/spring

�Aphidoletes in summer

�Responsive to Botanigard

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Potato Aphid Potato Aphid -- MacrosiphumMacrosiphum euphorbiaeeuphorbiae Foxglove Aphid Foxglove Aphid -- AulacorthumAulacorthum solanisolani

� Also called ‘Glasshouse Potato Aphid’

�Confusing => NOT the same as Macrosiphum

� This Aphid has emerged as the most serious pest

in our biological control systems

�There is no single effective control available

(not biological and not chemical)

�Very small populations cause very severe damage

to the crop (toxin injected into plant while feeding)

� Increasing host range includes crops not typically

associated with aphids (Poinsettia, Pelargonium)

Foxglove Aphid Foxglove Aphid -- AulacorthumAulacorthum solanisolani Foxglove Aphid Foxglove Aphid -- What Does NOT WorkWhat Does NOT Work

� Aphidius ervi can parasitize Foxglove Aphid

• But Aphid has strong alarm response

�Aphids disperse and/or drop from plant at the

slightest disturbance

�All Aphidius ‘probe’ Aphids before laying eggs

�Probing causes alarm response

�Control with Aphidius is poor at best

� A. ervi appears to prefer other hosts if given

choice (Potato Aphid)

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Foxglove Aphid Foxglove Aphid -- What Does NOT WorkWhat Does NOT Work

� Aphidoletes aphidimyza has some promise

� But

�Foxglove Aphid most problematic in spring

�Aphidoletes not very effective until mid-summer

�Aphidoletes will also trigger alarm response

�Aphidoletes seems to avoid some key host crops

of Foxglove aphids (e.g. Fuchsia and Calibrachoa)

� Is there an issue with mating ?

sometimes we need to get inventivesometimes we need to get inventive

Foxglove Aphid Foxglove Aphid -- What Does NOT WorkWhat Does NOT Work

� Chrysoperla - Green Lacewing

� Adults are not predatory

� Searching behaviour of larvae cannot be

integrated in bench grown crops

� High purchase cost of larvae prohibits use

as ‘biological pesticide’

� Dispersal flight behavior

of emerging adults

prevents reproduction

in greenhouse

Pupating Chrysoperla

Foxglove Aphid Foxglove Aphid -- Some HopeSome Hope

� Aphelinus abdominalis

�known to parasitize Aulacorthum

�displays less probing of aphids before egg-laying

could this improve chances of parasitization?

But

�Not very effective at

searching colonies

Can better searching

be learned ?

�Effect of cooler temperature ?

Aphid parasitized by Aphelinus

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� Micromus variegatus - Brown Lacewing

� Adults and larvae feed on Aulacorthum

� We observed reproduction in greenhouse

� No distinct dispersal habit

� Very active at cool temperatures

But

� Never eats all Aphids in a colony

� Feeds on parasitized Aphids

� Not specific to Foxglove Aphids

� Expensive


� Aulacorthum is sensitive to high temperature

�pest not usually a problem in summer at >30°C

• Some new pesticides in registration process

�compatible with (some) biologicals and effective

on Aulacorthum

• Several researchers are investigating

behavioral and physiological approaches

�SUPPORT OUR RESEARCHERS !!!

Foxglove Aphid Foxglove Aphid -- So What Do We Do ?So What Do We Do ?

� Introduce ‘barrage’ of Parasitoids in Winter

�Start before pest is visible

• Carefully inspect and treat incoming plants

�Botanigard works well on rooting bench

• Continuously monitor all crops for earliest

signs of foxglove aphids

� train and involve ALL greenhouse staff in scouting

• Use Endeavor on earliest signs of the aphid

� try to kill spots of residual or imported in-house

populations before they disperse into other crops

Biological Control of AphidsBiological Control of Aphids

� We cannot control “Aphids” with biologicals

� Need to control individual species of Aphids

� The presence of multiple species may create

problems with the control of individual aphids

� Predators and parasitoids have preferred Aphid hosts

� Different Aphids have different preferred crop hosts

� Not all Aphid/Crop combinations are equally attractive

to predators and parasitoids

• Spot-sprays for Aphid control may have serious

negative effects on biocontrol for other pests

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� Learn how to identify the species of pest

• Which aphid species are you trying to control

�get some equipment

�good stereo microscope 20-40X – good optics !

� learn how to use online resources for pest ID

�develop library of quick ID facts

• which crop is a likely host for which aphid

� train your staff for detailed scouting

� limit necessary pesticide applications to key host

crops for particularly problematic aphid species


Cotton Aphids - Apteres and Alates

Wings or No Wings ?Wings or No Wings ?

� Aptera are the wingless viviparious aphids that do

most of the damage

� Juvenile hormone prevents the development of

Aptera into mature insects (Alates)

� Alates are mature winged aphids

� Alates have a slower metabolism and take up less

food than Aptera

� Alates are harder to control with systemics

� Alates are less likely to be parasitized than Aptera

Important for all Aphid Biological ControlImportant for all Aphid Biological Control

� Turn off HAF fans around sunset / early night

�The airflow from the fans disturbs and distributes

the odor plume generated by the aphid/crop target

�Aphidius and Aphidoletes use this odor plume to

find aphid colonies

�Aphidoletes is only active at night. Aphidius

searches most actively in the early evening hours

�We improved aphid control results by

turning off HAF fans from 2 hrs before sunset until

about 4-6 hours after sunset

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How Beneficials Find Their PreyHow Beneficials Find Their Prey

Wind Direction

Flight Path of searching Predator/Parasitoid

Important for all Aphidius SpeciesImportant for all Aphidius Species

• Distribute insects rapidly after receiving

�Adult has short active lifespan of just a few days

�Rapid distribution of hatched adults is critical

• Watch for signs of Hyperparasitism

• Be patient, once you see the first mummies

�Small colonies less likely to attract parasitoids

�Control can lag several weeks

• Respond quick, if you don’t see any mummies

�Not all parasitoids work on all Aphids all the time

Experiences with EndeavorExperiences with Endeavor

� Pymetrozine NOT effective at temp <18°C

�at cool temperature aphid is not active enough

�does not take up enough active ingredient

� individual aphids survive - risk of resistance

• Application technique is critical

�Needs good ‘wet’ coverage inside the canopy

�Low Volume applications are not adequate

�Drench applications are NOT effective in

ornamentals - not enough transpiration in small

plants, and no coverage of flowers

Experiences with Botanigard on AphidsExperiences with Botanigard on Aphids

� Reasonably good results on some aphids,

but never complete kill and no residual

�only use in combination with other controls

� Phytotoxicity with liquid formulation on flowers

� WP leaves visible residue after repeat sprays

� Application technique critical:

�Small droplets - Highest Pressure / Small Nozzle

�No runoff to minimize spotting - watch spray

volume - use less than most other insecticides

• Appears to have some synergy with Endeavor

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Questions ?Questions ?

Albert Grimm

Jeffery’s Greenhouses Inc.

[email protected]

biological control at jeffery ’s greenhouses jeffery ’s ... · aphid control at our greenhouse...

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