Management of Flea Beetles in the Canadian Prairies

Alejandro CostamagnaDepartment of Entomology

CARP Project Team: Management of Flea Beetles in the Canadian Prairies

Hector Carcamo (AAFC Lethbridge)

Tyler Wist (AAFC Saskatoon)Jennifer Otani

(AAFCBeaverlodge)

John Gavloski(MAFRD Carman)

Barb Sharanowski (Univ. of Central Florida)

Rob Duncan (U of MB)

Thais Silva Guimaraes(U of MB)

TharshiNagalingam(U of MB)

Biology and Damage

J. Soroka

J. Bannerman

Manitoba Agriculture

Species Response to Seed Treatments

Tansey et al J. Econ. Entomol. (2008)

Management of Flea Beetles in the Canadian Prairies

1) Develop descriptive economic thresholds for flea beetles2) Identify the suite of natural enemies of flea beetles using molecular 

methods3) Define landscape characteristics that limit flea beetle populations 

and increase mortality of flea beetles by natural enemies4) Develop models to predict flea beetle emergence and major 

seasonal activity based on abiotic environmental conditions 5) Develop a comprehensive tool and set of management guidelines 

for canola producers.

Management of Flea Beetles in the Canadian Prairies

1) Develop descriptive economic thresholds for flea beetles2) Identify the suite of natural enemies of flea beetles using molecular 

methods3) Define landscape characteristics that limit flea beetle populations 

and increase mortality of flea beetles by natural enemies4) Develop models to predict flea beetle emergence and major 

seasonal activity based on abiotic environmental conditions 5) Develop a comprehensive tool and set of management guidelines 

for canola producers.

Economic Thresholds

• 25% defoliation - Nominal threshold in canola• Canola hybrids may compensate the damage• Montana study: 15-20% defoliation (Tangtrakulwanich et al. 2014)

Objective: Determine economic threshold for flea beetles in canola hybrids

Methodology

Foliar spray at defoliation level

Control 45% 25% 15-20% Seedtreatment

Fungicide only Fungicide + Insecticide

Matador (lambda-cyhalothrin) at 34 ml/ac

SY 4135 (Roundup Ready® hybrid canola)

Treatments

Control45% 15-20% 25%Seed

Small plots RCBD4-5 Replicates

Flea beetle abundanceand species compositionWeekly, 2.2 stage

Defoliation 3 times per week, until 2.240 plants per plot

Plant densityNo. of plants in 1m row

J. Soroka

Trials 2015-2017Regions Trials conducted Spraying occurred Yield data obtained

Manitoba 18 13 11Alberta: Lethbridge 11 11 10Alberta: Beaverlodge 3 3 3Saskatchewan 8 8 8

40 35 32Analysis of yield• ANOVA with block effect • Mean comparisons: Tukey’s test

2016• Early seeded trials: 4 • Late seeded trials: 3

Early seeded trials: Moderate flea beetle damage

40% 34% 28% 10% 40% 29% 15% 23% 28% 20%

TharshiNagalingam(U of MB)

Early seeded trials: High flea beetle damage

TharshiNagalingam(U of MB)

*waterlogging

Early seeded trials: Low flea beetle damage

15% 6%15% 28% 28% 2% 16% 18% 18%

TharshiNagalingam(U of MB)

Preliminary Conclusions• Results are variable among trials!

Early seeded trials:• Seed treatments: numerically higher yield• Foliar insecticide spray treatments: higher yield than control• Spray at 25% defoliation: good control

Late vs early seeded trials: • Late trials experienced less flea beetle damage and no significant

yield effect

Future analyses of data …

• Plant density

• Defoliation

• Flea beetle species abundance

• Planting dates

Management of Flea Beetles in the Canadian Prairies

1) Develop descriptive economic thresholds for flea beetles2) Identify the suite of natural enemies of flea beetles using molecular 

methods3) Define landscape characteristics that limit flea beetle populations 

and increase mortality of flea beetles by natural enemies4) Develop models to predict flea beetle emergence and major 

seasonal activity based on abiotic environmental conditions 5) Develop a comprehensive tool and set of management guidelines 

for canola producers.

Petri Dish Predation ExperimentsNo‐choice assays (generalist predators)

14

Wet paper in the bottom

Controlled growth chambers

6 FB

24h starved predators

Control: no predators

72 h of predation

P

Thais Silva Guimaraes(U of MB)

Petri Dish Predation Experiments

© Matthew Roth© Richard Migneault© Mardon Erbland © Terry Thormin

Thais Silva Guimaraes(U of MB)

Petri Dish Predation Experiments

© Matthew Roth© Richard Migneault© Mardon Erbland © Terry Thormin

Thais Silva Guimaraes(U of MB)

Petri dish predation experiments

© MJ Hatfield

Thais Silva Guimaraes(U of MB)

Nabis sp.

More Realistic Arenas…

14

Aldo Rios

P

Caged potted plants in growth chambers

Prey densities: 

o 5, 10, 15, and 20 FB

Control: no predators

Consumption:evaluated after 24 h 

Preliminary Conclusions

• Common ground beetles can consume flea beetles!

• More realistic experimental conditions?

• Field conditions?

Primers based on Cytochrome Oxidase I (COI) for P. striolata and P. cruciferae.

Barb Sharanowski (Univ. of Central Florida)

Management of Flea Beetles in the Canadian Prairies

1) Develop descriptive economic thresholds for flea beetles2) Identify the suite of natural enemies of flea beetles using molecular 

methods3) Define landscape characteristics that limit flea beetle populations 

and increase mortality of flea beetles by natural enemies4) Develop models to predict flea beetle emergence and major 

seasonal activity based on abiotic environmental conditions 5) Develop a comprehensive tool and set of management guidelines 

for canola producers.

Flea beetle sampling

Fields sampled

2015 29

2016 25

2017 25

Flea Beetles Populations – MB 2015

June 12

Flea Beetles Populations – Peace River 2015

June 3

Flea Beetles Populations – MB 2016

May 24

Flea Beetles Populations – Peace River 2016

May 17

Flea Beetles Populations – Lethbridge 2016

June 2

Flea Beetles Populations – SK 2016

June 9

Change in relative abundance Region Species 2015-2016 Historic Reference

Manitoba P. cruciferae 30 – 49 % 88-96% Lamb 1983

P. striolata 51 – 69% 4-12%

Manitoba P. cruciferae 78-92% Turnock et al. 1989

P. striolata 6-22%

Saskatchewan P. cruciferae 9 – 20% 40% Soroka 2012

P. striolata 80 – 90% 50%

Alberta P. cruciferae 66 – 86 % > 99% Cárcamo et al. 2006

(Lethbridge) P. striolata 13 – 33% very few

Alberta P. striolata 91-99% dominant Cárcamo et al. 2006

(Beaverlodge)

J. Soroka

Arc Map 10: Carman

2 km 

• Landscape composition – different scales(up to 2 km radius) 

• Digitally quantified: ArcGIS 10• Habitat diversity (Simpson’s diversity Indices)

• 30 bi‐directional Malaise traps• Between soybean and adjacent habitats

Landscape characteristics

Natural enemy movements

250 m500 m1000 m1500 m2000 m

©ishansamaranayake

Lady beetles (Coccinellidae) Minute pirate bugs (Anthocoridae) Damsel bugs (Nabidae) Brown lacewings (Hemerobiidae) Green lacewings (Chrysopidae) Hover flies (Syrphidae)

Landscape Effects on Flea Beetles Populations

% Canola

Partial residuals

% Other crops

Partial residuals

CFB = I*** - Canola*** - Other crops**AIC = 70.318r2 = 0.479F2, 23 = 12.53p = 0.0002

*** p < 0.0001** p < 0.001 Other crops: alfalfa, berry patch, clover, faba beans, fallow, flax, forage, hay, 

hemp, lentils, mustard, peas, potatoes, research plot, reserved plot, sunflower, vegetable plot 

Crucifer Flea Beetle  (1 km radius)Thais Silva Guimaraes(U of MB)

CFB = I*** - Canola*** ‐ Cereals**AIC = 67.680 r2 = 0.457 F2, 23 = 11.52 p = 0.0003

*** p < 0.0001** p < 0.001 Cereals: barley, canary grass, corn, oats, 

rye, wheat

% Canola

Partial residuals

Partial residuals

% Cereals

Striped Flea Beetle  (2 km radius)Thais Silva Guimaraes(U of MB)

Summary and Conclusions

• Seed treatments: good control• Spray at 25% defoliation: good control • Increased dominance of striped flea beetles• Generalist predators can attack flea beetles!• Proportion of canola in landscape related to flea beetle abundance

• Lots of data still to be processed!

THANK YOU !Cárcamo Lab

Jennifer Otani

Tyler Wist

Rob Duncan

John Gavloski

Costamagna Lab