World IPM - Think Like An Insect:

Outwit, Outplay and Outlast

Dr Robert Mensah PSM

Senior Principal Research Scientist & Director

NSW Department of Primary Industries

Australian Cotton Research Institute, Narrabri, NSW

Australian Cotton:

Pest management Challenges & Threats

▪ The Cotton Industry is dependent on Bt

cotton

– Pest resistance to Bt cotton

– Emergence of sucking pests

▪ Within field the cotton cropping system is

generally a monoculture which :

– Lacks ecological diversity because it

discriminates against natural enemies

of crop pests

– Reduces the activity of natural

enemies & retards biological control

Pest Management:

Sucking pest problems▪ Emergence of sucking pests as major pest on transgenic

cotton– Insecticide use against sucking pests is increasing

▪ Neonicotinoid - used as seed treatment – causes resistance selection pressure against cotton aphids down the

line (late season)

▪ Industry is inadvertently building insecticide resistance to sucking pests

▪ Other countries such as China, Pakistan, India, Brazil, USA etc are facing similar problems (see next slide)

▪ Australia needs to minimize synthetic insecticide use against sucking pests

▪ Think like an insect: Outwit, Outplay and Outlast

Solenopsis mealybug

World IPM: Increased use of synthetic

insecticides against sucking pests on Bt cotton

Dr. K.R. Kranthi Cotton statistic and news. No. 38 16th December, 2014 Cotton Association of

India – Elaboration PAN-UK

Sucking pests: Whiteflies, thrips and leaf hoppers, mirids, stinkbugs

So, what do we have to do with these

insects we call “pests”?

▪ Understanding that insects are living organisms

and can survive whatever we throw at them

▪ Understanding that there is an insect world

(community) out there

– They communicate & can react to our pest

management & other farm activities

▪ We need to “Think Like an Insect” in order to

“manage” them effectively

How can one “Think Like an Insect”?

▪ Understand the behaviour of insects on your crop

– Take note of what they like or hate

▪ Manipulate the insect behaviour to “manage” them

▪ Insecticide should only be used as last resort

▪ Use your friends (beneficial insects) in the insect

community to help you manage pests

Botanical products:

How insects interact with Plants

(Insect Plant interactions)

▪ Plants have Secondary Plant compounds (SPCs)

that influence insect behaviour

▪ SPCs serve as cues stimulating insect’s interest

▪ Many SPCs protect against pest infestation

▪ SPCs from non-host plants, sprayed on host

plants can change pest behaviour to avoid the

host plant

Insects after landing on a plant

▪ Contact and evaluate the leaf surface, thereafter

▪ Accept or

▪ Reject the plant for oviposition or feeding

▪ Some insects feed less and can delay their

development, if the plant is not preferred or

▪ Avoid feeding and starve to death

Thus, Chemical compounds on cotton leaf

surfaces can be

▪ Attractants (attracts insects to the plant)

▪ Stimulants (influence insects to feed or oviposit on the

plant)

▪ Deterrents (suppress oviposition and feeding)

▪ Repellents (influence insects to move away from the

plant)

As a result

▪ Behavioural manipulation methods such as

– Stimulants

– Deterrents (Sero X®)

– Attractants (Magnet®)

– Repellents (Sero X®)

– Chemical cue suppressants (e.g. PSOs®, Sero

X®)

– Direct kill (Sero X®; PSOs®, NPV)

▪ can be used to suppress pests on crops

and maximize yield

Petroleum spray oils:

▪ PSOs can act as Chemical cue suppressant

▪ It deter egg lay

▪ It can deter pest feeding

▪ It can cause direct kill through suffocation

Chemical cue suppressants

Petroleum spray oils (PSOs)

▪ PSOs can mask the effect

of chemical volatiles

emitted from the plant

▪ This can confuse the

insect in the choice of

– oviposition and

– Feeding on the plant

▪ The insect will think it is

not a good host plant

Prophylactic

(PSO)

Threshold (P

SO)

Conventional

Control

0

0.25

0.5

0.75

1.0

1.25

1.5

1.75

2.0

2.25

2.5

2.75

3.0

3.25

3.5

Nu

mb

er/

m/S

am

ple

date

+95%

CI

Figure 4. Individual numbers of coccinellids at Peats Ridge.eggeggegg

egg

very small+small larvae

medium + large larvae

Mechanisms underlying the deterrent

activity of PSO against cotton pests

▪ This was determined

through

– Chromatographic (GC)

analyses of solid phase

micro-extraction (SPME)

sampled from PSO

treated and Untreated

cotton plants.

– Wind tunnel studies

Chromatographic analysis:

Volatiles from cotton plants

Treated with water Treated with PSO

SLW Adults: Behaviour on cotton cropsMensah & Young (2017). BIOCONTROL SCIENCE AND TECHNOLOGY, VOL. 27, NO. 7, 844–866

▪ The more SLW nymphs per leaf, the fewer the

adults/leaf

▪ Once the number of SLW nymphs increased to

approx. 70 per leaf, a negative feedback regulatory

effect occurs. This effect

– reduce the survivorship of nymphs & adults

– cause the emigration/movement of the adults

from contaminated leaves in search of new

resource

Mensah & Young (2017). BIOCONTROL SCIENCE AND TECHNOLOGY, VOL. 27, NO. 7, 844-866

SLW Adult movement: Relationship

between SLW adults and nymphs/leaf

Other products include:

Semiochemicals Fungal biopesticides

0

0.5

1

1.5

2

2.5

3

10-Mar-10

14-Mar-10

17-Mar-10

24-Mar-10

31-Mar-10

07-Apr-10

No

. S

LW

ad

ult

s/l

ea

f

Dates of assessment

2L/ha Sero X

2% v/v Canopy +0.50L/ha Shield

Unsprayed (control)

0

2

4

6

8

10

12

14

10-Mar-10

14-Mar-10

17-Mar-10

24-Mar-10

31-Mar-10

07-Apr-10

No

. S

LW

nym

ph

s/le

af

Dates of assessment

2L/ha Plant extract 2

2% v/v Canopy +0.50L/ha Shield

Unsprayed (control)

Effect of Sero X on Green mirids on

commercial cotton crops, ACRI, 2010-11

ZAPPA trap: Sampling sucking pests

▪ Green mirids and green vegetable bugs, are not affected by

the Bt toxin.

▪ They are highly mobile, and their flight phenology is difficult to

understand.

▪ Current industry sampling techniques for these pests may not

be providing us with enough information about when these

pests arrive on the farm and the numbers infesting the crop.

▪ The Zappa trap can be effective monitoring tool to determine

arrival time and their numbers,

▪ This will lead to being able to predict peak activity within the

crop enabling effective control to be applied in a timely fashion

Targeted Insect Pests

Zappa trap works effectively on most nocturnal

adult insect pests. The target pests include:

• Lepidoptera: Moths

• Hemiptera: Mirids, green vegetable bugs and

stink bugs, Leafhoppers and possibly silver leaf

whiteflies, etc.

• Zappa is selective on most predatory insect adults

based on the operating wavelength of the globe

Zappa traps

Version with old catcher Version with revised catcher

Green mirid adults caught/trap compared with GM

adults & nymphs/m on plants, 2016/17

GM adults Catch/trap GM adults & nymphs/m (Plant-Visual)

Green vegetable bug adults caught/trap compared

with GVB adults & nymphs/m on plants, 2016/17

GVB Adults Catch/trap GVB adults-nymphs/m (Plant-Visual)

Predatory beetle adults caught/trap compared with

adults & nymphs/m on plants, 2016/17

Predatory beetle adults Catch/trap Pred beetles adults/m (Plant-Visual)

Conclusions

▪ Insects are living organisms with their own

communities

– We cannot “bully” them with insecticides

– They will react and throw it back at us

▪ Understanding their behaviour is crucial for

effective pest management

▪ Pro-active management of pests with products that

makes the plant unsuitable for insect egg lay,

feeding and survival is the key IPM principle

▪ Intervention with synthetic insecticide should be

seen as a last resort or as needed basis.

If we can “Think Like an Insect” we can

Outwit, Outplay and Outlast Then we have

every reason to celebrate.

Acknowledgements

• Special thanks to

• Alison Young, Carolyn Palmer, Lori Nemec, Stacey

Cunningham and all my casual staff

• All growers and Consultants who collaborated in the trials

presented

• Special thanks to Mr Peter Glennie and Iain Macpherson

who have collaborated in my project trials since 1992

• All my commercial partners particularly InnovateAg (Sero X ®)

and Caltex Pty Ltd (Canopy oil)

• The CRDC for providing funding for my project over the past

26 years

• I am indebted to NSWDPI for continue employment for the

past 26 years

Thank You

•This presentation Closes my Chapter in the Australian Cotton Industry