Wireworm management in grain production

Dr. Christine Noronha Agriculture and Agri-food Canada, Charlottetown

Research and Development Centre

Presentation to ACORN November 24, 2015 - PEI

What are Wireworms •  Larvae of click beetles. •  Several species cause crop damage. •  An emerging pest worldwide. •  Affect a wide variety of crops. •  Can render root crops unmarketable. •  Very limited means of control.

Lifecycle of Wireworms

They pupate in the soil and emerge as adults in the spring. Lifecycle 5 years

Spring-early summer Adults lay 100-200 eggs in the soil

Spring – damage seeds and seedling roots

Later Fall- hibernate in the soil. Return to the surface in the spring.

Click beetles

Larvae

Fall damage root crops

May 2010 eggs

May 2011

May 2012

May 2013

May 2014

May 2015eggs

Yr.1 L

Yr.2 L

Yr.3 L

Yr.4 L

Yr.5 L – pupa -Adults hibernate

Hibernate

Hibernate

Hibernate

Hibernate

Once a field is infested it will be remain so until wireworms are killed

Larval Duration

1 female lays 100-200 eggs

If only 8 larvae survive to become adults in year five, with 4 females and four males each females produces 100-200 eggs Five years later

Ten years later

Population Increase

2012 2013 2014 2015 2016 2017

15 1000

5 200

2 50

6 500

1000 3000

Yr1 1000 Yr2 Yr3 Yr4 yr5

Yr1 200 Yr2 1000 Yr3 Yr4 Yr5

Yr1 50 Yr2 200 Yr3 1000 Yr4 Yr5

Yr1 0 Yr2 50 Yr3 200 Yr4 1000 Yr5

Yr1 500 Yr2 0 Yr3 50 Yr4 200 Yr5 1000

Yr1 3000 Yr2 500 Yr3 0 Yr4 50 Yr5 200

Damage can be worse in some years and less is others in newly infested fields?

•  Agriotes sputator (NS, NB and PEI •  Agriotes obscurus PEI and NS •  Agriotes lineatus PEI and NS

•  Hypnoidus abbreviatus •  Ctenicera pulchra •  Dalopius sp

European Species

Other species

48 species of click beetles in PEI, 98 in NB and 101 NS

Click Beetle Species

Where do they prefer to lay their eggs Sod fields

Pasture fields

Under-seeded fields

Undisturbed fields with green plant material are preferred

Adults will also lay eggs in bare soil, egg survival may be compromised

Wireworm have an aggregated distribution in the field

Monitoring Click Beetles

•  Wireworm populations have been closely monitored in PEI using pheromone traps.

•  Pheromones are chemical produced by females to attract males.

•  Pheromone are available for some of the European species.

•  Traps collect only male beetles.

Range  of  beetle  

numbers    

Prince  County  No.  of  Farms  

Queen  County  No.  of  Farms  

Kings  county  No.  of  Farms  

2009   2012   2014   2009   2012   2014   2009   2012   2014  

0   4   4   1   0   0   0   2   1   0  1-­‐10   16   25   2   8   6   0   10   12   0  11-­‐50   7   5   7   7   4   3   3   7   2  51-­‐100   0   2   1   1   3   3   0   0   1  101-­‐500   0   2   4   2   5   4   0   0   2  501-­‐1000   0   0   2   0   5   2   0   0   1  >1000   0   1   0   0   3   5   0   0   0  

Total  #  of  beetles  

214   1969   2812   1308   10,438   14,152   76   197   1298  

Total  per  trap  

7.9   50   83   72   401.46   416.23   5.4   9.8   108  

Table 1. Comparisons of the number of farms with beetles numbers ranging for 0 - >1000 in 2009 and 2012, and 2014 for each county in Prince Edward Island.

** 500 beetles and over can result in crop failure.

Survey of Click beetles across PEI

15%

5%

10%

Incidence of wireworm reports across Canada

1%

5% 10% 10%

Potential to impact agriculture •  Once infected, agricultural land will remain

infected until adequate control measures to eliminate the larvae are implemented.

•  If wireworms are not controlled, the land may become a important source of adult beetle that will infest other fields.

•  Because of the wide host range, good agricultural land may become unsuitable for crop production.

•  5 year life cycle. •  Soil dwelling. •  Difficult to monitor because of aggregated field

distribution. •  Several generations in the same field. •  Damage occurs in the spring and fall. •  Feed on a wide variety of crop species – oats, wheat,

barley, clover, corn, carrots, lettuce, onions, peas, potatoes, parsnips cabbage, beans, rutabagas etc.

Wheat field in Alberta, 2012

Courtesy of Dr. Bob Vernon

Barley field with wireworm damage

Wireworms attack germinating seeds

co2 co2 co2 co2

Grain crops •  Grain crops provide a good food source for

wireworms •  Growing grain for several years in a row

can influence the buildup of wireworm population

•  Under-seeding results in abundance of food which is beneficial to wireworm survival

18

CROP ROTATION STRATEGY TO REDUCE WIREWORM

DAMAGE

Wireworm research at AAFC Charlottetown: Crop Rotation Study To Reduce Wireworm Damage (funded by

Pest Management Centre, 2007-2010) Brown Mustard, Buckwheat, Barley /Clover

Crop Rotation

Crops

Total Market yield (t/

ha)

Tubers with no Damage

(t/ha)

Average Number of Holes per tuber

Tonnes/ha lost due to

damage (for Processing)

(t/ha)

Tonnes/ha Marketable

(for Processing)

(t/ha) Brown Mustard 45.6 a1 16.2 a 04 a 0.5 a 45.1 a

Buckwheat 45.9 a 12.6 a 06 a 2.6 a 43.3 a

Barley 47.3 a 2.3 b 20 b 16.8 b 30.5 b

Table 1. Total market yield, number of undamaged tubers, holes per tuber, tonnes per hectare lost due to wireworm damage and marketable yield for the processing market in a potato crop following a 2 year rotation with brown mustard, buckwheat, barley/clover or alfalfa at Hazelbrook in Prince Edward Island, Canada.

Why does Brown Mustard work? •  Because the plant tissue has

Allyl-glucosinolate (GTC) •  When plant material starts to

breakdown and enzyme Myronase reacts with the tissue to produce Isothiocynates (ITC)

Glucosinolate

Enzyme Myronase

+ Isothiosynate ITC

Why does Brown Mustard work?

•  The plant tissue has Allyl-glucosinolate (GTC)

•  2-phenylethyl in its roots which is toxic to insects

•  Brown Mustard (Brassicae juncea var. Centennial) 10lb/ac or 11.2kg/ha

•  Buckwheat (var Mancan) 40lb.ac or 44.8kg/ha •  2 crops /year •  Fertilizer 300lb/ac or 335kg/ha 17:17:17 banded at

planting in the spring •  Plant early June

Crop Rotation

•  Brown Mustard (var Centennial) 8-10lb/ac or 11.2kg/ha

•  Buckwheat (var Mancan) 40lb.ac or 44.8kg/ha •  2 crops /year •  Fertilizer 300lb/ac or 335kg/ha 17:17:17 banded at

planting in the spring •  Plant early June •  Disk the crop in late July before seeds mature

Crop Rotation

DISK THE CROP IN LATE JULY BEFORE SEEDS MATURE

Crop Rotation

•  After two-three weeks harrow the field to level it •  Depending on the seeder you may need to roll it

before planting, mainly because you don’t want the mustard seed planted too deep

•  Do not need to add fertilizer for the second planting

Crop Rotation •  The 2nd crop should go in by the mid-late August •  Wireworms come to the surface to feed by mid to

late September •  You want the crop established and producing the

chemicals •  This second crop does not need to be disked as it

will act as ground cover and will not produce seeds

Buckwheat as ground cover in the fall (PEI)

Brown Mustard as ground cover in the fall (PEI)

Buckwheat as ground cover in the fall (PEI)

Brown Mustard as ground cover in the fall (PEI)

Buckwheat as ground cover in the fall (PEI)

Brown Mustard as ground cover in the fall (PEI)

Treat the brown mustard and buckwheat like a crop

BIOLOGICAL CONTROL RESEARCH

Todd Kabaluk AAFC, Agassiz, BC

X X

Can Metarhizium control wireworms by controlling click beetles? (in the years leading up to planting potatoes)

X

First of all, is Metarhizium even pathogenic to the adult beetles?

Tests in the lab say YES

Metarhizium spore dust

Metarhizium spore spray

What about in the field?

Metarhizium spore granules

Conidia spray

Conidia dust

Conidia granules

Number of days after treatment

% beetle mortality

Matador (λ – cyhalothrin) -spray positive control

Application of Metarhizium spores kills click beetles in the field

The Concept – Attracting Beetles to Bands of Biocontrols using Pheromone Granules

Click  beetles  recaptured  16  days  post-­‐treatment  

Pheromone  granules  synergize  the  efficacy  of  Metarhizium  when  targe>ng  A.  obscurus  click  beetles  using  a  banded  applica>on  

Mean  number  +  s.e.  of  beetles  per    passive  piMall  trap  (mean  of  8  traps  in  each  of  5  replicaPons  =40  traps/data  point)    

Untreated

 

Dead  

Metarhiziu

m  

Almost  all  beetles  killed  

•  Use Bait traps •  Could be done in the spring or fall. •  Depending on the size of the field at least 15

bait stations per acre

Assessing wireworm infestation in a field

Lightly pack soil back down (leave for 7 days) Place soil back in hole

Place approximately ¾ cup of cut up carrots in the hole around the flag

Place wire flag in the center of the hole

Set Bait probe on top of the ground and step on it creating a nice circular hole 3 ½ inches across and 5 ½ inches deep

Placing Bait Traps

Place wire flag in the center of bait probe and push the probe into the ground

Pull bait probe from the ground

Place bait probe into a 12lb bag and remove sample

Check to see if any carrots remain in the hole and if some remain collect them as well

Label bag with appropriate tag and tie and store at 4C until time to sort for wireworms

Collecting Bait Traps

•  Count the number of wireworms and calculate number per bait

•  Threshold 1-2 wireworms per bait •  Finding no wireworms does not necessarily

mean that none are present in the field. The higher the number of bait stations the better the accuracy

Assessing wireworm infestation in a field

Baiting your field Baits should be placed randomly across the field to compensate for this aggregated distribution of wireworms

49

Doing On-Farm research

50

60

50

75

100

100

Treatment A Treatment B

40

80

30

25

35

40

30 20

50

60

50

75

100

100

Treatment A Treatment B

40

80

30

25

35

40

30 20

6 rows 30 rows

Treatment A Treatment B Check

12+ rows 12 + rows 12+ rows

STRATEGIES TO REDUCE DAMAGE 1. Find out if you have wireworms in your field and

assess populations. 2. If you work up a long term sod field do not plant a

valuable crop. 3. Plant brown mustard (Brassice juncea var centennial)

or buckwheat (var Mancan) as a rotation crop as shown above.

4. Try not to plant a preferred host such as grain every year.

5. For root crops harvest early before wireworms come up to the surface to feed in the fall.

Contact information Christine.noronha@agr.gc.ca - Phone 902-370-1374