Insect Insights:

There is a new paradigm in seed

treatments for corn and soybeans

Gilles Quesnel

Independent Agronomist, Winchester

New Neonicotinoid Seed Treatment Regulation

• New class of pesticides - Class 12 for corn and

soybean seeds treated with imidacloprid,

thiamethoxam and clothianidin (Neonics).

• New regulation introduced to ensure that neonicotinoid-

treated corn and soybean seeds are used only when

there is a demonstrated pest problem.

• Integrated Pest Management approach.

What is IPM?

• Integrated Pest Management

• Official term came into use in 1970s but approach

started back in the 1950s 6000 BC

• A systems approach to pest control that uses all

available technologies to efficiently and economically

reduce the pest population while respecting health and

the environment

• Continuously evolving as science improves on pest

knowledge, monitoring tools and control options

Steps In IPM Process

1. Understand the pest (ID, lifecycle, damage,

timing and association with the crop)

2. Conduct field monitoring (scouting)

3. Using injury and action thresholds

4. Least disruptive control strategy

(Cultural, Chemical, Biological, Genetic)

5. Evaluate actions

6. Keep records

Steps In IPM Process

1. Understand the pest (ID, lifecycle, damage,

timing and association with the crop)

2. Conduct field monitoring (scouting)

3. Using injury and action thresholds

4. Least disruptive control strategy

(Cultural, Chemical, Biological, Genetic)

5. Evaluate actions

6. Keep records

Misidentification Leads to Unnecessary

Applications

2014

Wireworm species by soil texture class

0

10

20

30

40

50

60

70

80

90

100

Clay Clayloam

Loam Loamysand

Sandyclayloam

Sandyloam

Silt loam Silty clayloam

Pro

po

rtio

n o

f to

tal

wir

ew

orm

s f

ou

nd

(%

)

Soil Texture Class

Limonius agonus

Hypnoidesabbreviatus

Agriotes mancus

Hemicrepidius sp.

Melanotussimulis/cribulosus

Melanotuscommunis/dietrichi

Aeolus mellillus

2014

Wireworms found associated with time

of sampling

0

10

20

30

40

50

60

70

80

90

100

WWM trap(before

emergence)

WWM trap(VE-V1)

VE-V1 V2-3 V4-5 V6-7 V8-V11

Pro

po

rtio

n o

f to

tal

wir

ew

orm

s f

ou

nd

(%

)

Crop stage at time of sampling

Limonius agonus

Hypnoides abbreviatus

Agriotes mancus

Hemicrepidius sp.

Melanotussimulis/cribulosus

Melanotuscommunis/dietrichi

Aeolus mellillus

Steps In IPM Process

1. Understand the pest (ID, lifecycle, damage,

timing and association with the crop)

2. Conduct field monitoring (scouting)

3. Using injury and action thresholds

4. Least disruptive control strategy

(Cultural, Chemical, Biological, Genetic)

5. Evaluate actions

6. Keep records

Easy Scouting = Easier Management

• The easier it is to scout for a pest, the easier

it is to apply a control strategy when needed

• Much easier to find above ground pests

– eg. Bean leaf beetle and soybean aphids

10

Soil Pests are Complicated

• Harder to find below ground pests

• Good understanding of grubs and life cycle

• Seedcorn maggot tough to scout for until

damage is done

• Still much to learn about wireworms which

are not easy to scout for

• Lack of easy, accurate scouting methods

leads to the use of pesticides as insurance

11

Trapping/Monitoring Improvements

• Research always working towards improving

trapping/monitoring methods

• Learning more about wireworm bait dynamics

• But still needs improvements

• Potential for monitoring of adult click beetles with

traps

– Current pheromone lures for European species

only which are not prevalent in Ontario yet

12

Bait Type and Location

Differences

Flour

Grain

Potato

0

10

20

30

40

50

60

edgefield

grass

• Flour and grain baits were not significantly different but

potato baits had the lowest success rate

• Bait traps along the fields edge were more successful

Steps In IPM Process

1. Understand the pest (ID, lifecycle, damage,

timing and association with the crop)

2. Conduct field monitoring (scouting)

3. Using injury and action thresholds

4. Least disruptive control strategy

(Cultural, Chemical, Biological, Genetic)

5. Evaluate actions

6. Keep records

Need Threshold Improvements

• Many are action thresholds and decades old

– do not take into consideration the cost of control,

effectiveness of control options or commodity price

• Tend to have more reliable thresholds for new

emerging/invasive pests since research is very

recent – soybean aphids

• Meaningful thresholds for below ground pests are

extremely challenging to develop and use.

• Not many thresholds that take into consideration a

combination of pests attacking the crop at once

– Soybean defoliation threshold being the exception

15

Steps In IPM Process

1. Understand the pest (ID, lifecycle, damage,

timing and association with the crop)

2. Conduct field monitoring (scouting)

3. Using injury and action thresholds

4. Least disruptive control strategy

(Cultural, Chemical, Biological, Genetic)

5. Evaluate actions

6. Keep records

Challenges in IPM

• Usually looks at one pest/one crop at a time

• Challenging to consider all pests/cropping systems

approach

• Hard to predict all impacts each approach has on

non-targets and secondary pests

• Perception that organic products or biocontrol do not

have negative impacts on environment

17

Cultural Control

• Crop rotation has limited impact, given

grassy weeds present along fields edge

• Tillage can help reduce population levels

– However, timing when larvae are at surface key

– Need 3 or 4 passes to see some effect

– Negative impacts to soil health

– Not selective – can impact natural enemies too

18

Pros and Cons to Biocontrol

• Usually a lag time before biocontrol agents build up

• Require ideal field conditions

• Some are not long lasting (eg. nematodes and

entomopathogens)

• Very costly if application required (no mass

production of biocontrols)

• Easily killed with pesticide applications

• Some are not selective

– eg. nematodes impact bumble bees and other soil

nesting bees

19

20

Wireworm infected with Metarhizium spp.

T Kabaluk AAFC

Entomopathogenic nematodes used for grub control.

Dave Cappaert, MSU, Bugwood.org

Entomopathogenic Nematodes

Impact on Bumble Bees

21

Entomopathogenic nematodes used for grub

control. Dave Cappaert, MSU, Bugwood.org

Dutka A, McNulty A, Williamson

SM. (2015) A new threat to bees?

Entomopathogenic nematodes

used in biological pest control

cause rapid mortality in Bombus

terrestris. PeerJ 3:e1413

https://doi.org/10.7717/peerj.1413

IPM Challenges

• Traditionally seed treatment as an ‘insurance policy’

without identification of a target pest appears to run

counter to the basic principles of IPM.

• Yet we do it a lot. Especially with fungicide seed

treatments. What about Bt corn, RNAi, or traditional

crop resistance?

• Is targeted “insurance” legitimate IPM?

22

seed treatments

23

24

Harmful to honeybees when used

on some crops but not all crops

Comments Within Document

• The preliminary risk assessment identified a residue

level for imidacloprid of 25 ppb

– Below this level – effects are unlikely

• Data show that citrus and cotton may have residues

in pollen and nectar above the threshold level. Other

crops such as corn and leafy vegetables either do

not produce nectar or have residues below the

PMRA/EPA identified level

• Assessment only pertains to honeybees. It does not

consider native bees (eg bumble bees)

25

No potential risk to bees was indicated

for seed treatment use.

• The exposure route of dust generated during

planting of treated seed was also considered. Dust

generated from planting of neonicotinoid treated corn

and soybean seed was previously identified as a

concern in Canada, and risk reduction measures

were put in place in 2014 to reduce exposure to dust

during planting of treated corn and soybean seed.”

26

Neonicotinoid seed treatments

What did we learn?

Acknowledgments: Dr. Art Schaafsma, Dr. Victor Limay-Rios,

Dr. Yingen Xue, Tracey Baute Jocelyn Smith, Gabriel Forero Todd Phibbs, Darrel Galbraith

Jen Bruggeman

Neonics in vacuum planter exhaust during planting

0.0029 to 0.11 g ai/ha in exhaust

00.05 to 7.69 % from soil dust

92 to 99.95 % from seed

0.01 to 0.44 % of seed applied neonic

Source of >>92 % of neonics moving

in and around corn fields Xue, Y., Limay-Rios, V., Smith, J., Baute, T., Forero, L. G., & Schaafsma, A. (2015). Quantifying Neonicotinoid Insecticide Residues Escaping during Maize Planting with Vacuum Planters. Environmental science & technology, 49(21), 13003-13011. DOI: 10.1021/ acs.est.5b03753

The problem: seed abrasion in vacuum planters Two key sources - Talc - Field Dust 13 lbs/a of abrasive dust going through vacuum system

98% comes from field through intake

Solution: Pre-filter followed by post filter

Vacuum Planter

vacuum

exhaust deflector engaged

vacuum

line

seed

disk

exhaust

deflector

vacuum

exhaust sample bags

engaged

vacuum

intake

Goal for all seed treatment pesticides - reduce residue escape by > 95%

1. Pesticide applied stays on seed

2. Filter/re-direct exhaust dust INTO soil

3. Vacuum intakes – clean air

4. Non-abrasive seed lubricants

5. Conservation tillage

Conflicting Perspectives of Value

• Insurance - risk/benefit?

– economics

• Yield

seed treatments

Corn Yield Response

to Neonic Seed Treatment 2015

Cooperator: Bycrest Farms

Hybrid: Dekalb DKC 50-78

Previous Crop: Soybeans

Pricing: Corn - $5/Bu

Treatments Yield (Bu/a) Ave. Yield Yield Diff. Net $/acre

Neonic 236 236 + 7 Bu/a + $35

Fungicide 230 229

Neonic 236

Fungicide 225

Neonic 236

Fungicide 231

Corn Yield Response

to Neonic Seed Treatment 2014

Treatments Bu/Acre Diff. Bu/acre

Check 172

CruiserMaxx 250 172 - 2 Bu/ac

CruiserMaxx 250 168

Check 168

Check 170

CruiserMaxx 250 163

Cooperator: Cedar Lodge Farms

Planted: May 21, Harvested Dec 1st

Hybrid: Mycogen 2J337, Previous Crop: Corn

New Seed Treatment Products Corn

• Insecticide Seed Treatments

– Chemical Group 28 - diamides

• Fortenza (Syngenta)

– Active ingredient: cyantraniliprole

– Cutworm, wireworms and European chafer grubs

• Lumivia (DuPont)

- Active ingredient: chlorantraniliprole

- Potential registration in spring 2016

- Wireworms, grubs, cutworm, seedcorn maggot (suppression)

36

• Less systemic than neonics

• Less water soluble

• Very effective on lepidoptera (caterpillars) and some fly

and beetle larvae

• Rate dependent efficacy on other soil pests

38

Group 28 – Diamides

Group 28 – Diamides

• Products already used:

–cyantraniliprole: Lumiderm (seed treatment)

–chlorantraniliprole: Coragen, Voliam Xpress

• Excellent mammalian, bird, fish, earthworm etc safety

• Relatively low impact on beneficials (some exceptions)

• “Reduced Risk” but this doesn’t mean “No Risk”

Coragen Bee LD50 Oral = 118 ug/bee

Bee LD50 Contact = 82 ug/bee

clothianidin Bee LD50 Oral = 0.0038 ug/bee

Bee LD50 Contact = 0.044 ug/bee

39

Fortenza Label

• Toxic to bees. This product is systemic and bees can be

exposed to product residues in flower, leaves, pollen

and/or nectar resulting from seed treatment applications.

However, when this product is applied and used

according to label directions, risk to bees is expected to

be negligible

• Follow best management practices to help minimize dust

exposure to pollinators during planting of treated seed;

refer to the complete guidance “Pollinator Protection:

reducing risk from treated seed” on the Health Canada

website (www.healthcanada.gc.ca/pollinators)

40

Can Seed Treatments Fit in IPM

Yes, if:

We fix the problem with dust escaping the planter for

ANY seed treatment

We can be proactive and minimize the off target

exposure

Move towards using reduced risk products

Low to no impact on non-targets

Low to no residues in pollen or nectar

≠ But wall to wall use leads back to increased risk

41

For 2016

• Take IPM Course for corn and soybeans

• Consider doing on-farm seed treatment trials

– Fungicide only

– Fungicide + Neonic

– Fungicide + diamides (e.g. Fortenza)

50

Gilles Quesnel Twitter: @GillesQuesnel

Independent Agronomist, Winchester ON 613-294-7977

Thank You