The Pea Leaf Weevil Management Guide · The map below displays the incidence of pea leaf weevil in 2018, as monitored by the government of Alberta. Officials advise that central Alberta

This document does not fully comply with all applicable guidelines for accessible digital documents: for an accessible version, visit Syngenta.ca or contact the Customer Interaction

Centre at 1-87-SYNGENTA (1-877-964-3682).

MANAGEMENT GUIDE

THE

WEEVILPEA LEAF

Introduction

Pea leaf weevil management starts hereThe pea leaf weevil (Sitona lineatus) is an invasive pest that poses an increasing threat to field pea and faba bean production in Western Canada. The insect can cause damage at multiple stages of the life cycle, leading to significantly reduced yields.

Use this guide to help you correctly identify, scout and manage this damaging insect in your pulse crops. With the agronomic tips and actionable management strategies found in the pages ahead, you’ll be well equipped to make informed decisions about protecting your pea and faba bean crops.

Contents

WHA

T’S

IN T

HIS

GUID

E?The Pea Leaf Weevil Management GuideIdentification 5

Life cycle 6

Outbreak factors 7

Affected areas 8

What’s at stake? 10

Management practices 11

Scouting 13

Cruiser Maxx® Vibrance® Pulses seed treatment 15

Matador® insecticide 19

Voliam Xpress® insecticide 21

PEA

LEAF

WEE

VILS

Pea Leaf Weevil Management Guide 5

IdentificationAdult

Adult pea leaf weevils are slender, greyish- brown beetles about 5 mm long with a broad-shaped snout. Three light-coloured stripes extend length- wise down the thorax and sometimes the abdomen.

Larvae

Pea leaf weevil larvae are C-shaped and measure about 3 to 6 mm in length. The legless larvae are soft-bodied and milky white with a dark brown head.


Life cycleThe pea leaf weevil produces one generation per year and develops through four life stages: egg, larvae, pupae and adult.1,2

Season Life cycle

Winter Adults overwinter in alfalfa or other perennial legume crops, ditches and shelterbelts.

Late April– to early May

Adults emerge from their winter habitat and begin feeding on available leguminous greens.

May to June Adults walk or fly (at temperatures above 17°C) to legume fields to reproduce. Females lay up to 1,500 eggs in the soil near developing plants. Eggs are small, smooth and oblong. They are white when laid, but turn nearly black at hatching.

July Larvae feed on pulse crop nodules and grow through five instar stages, then burrow into the soil and pupate.

August Adults emerge and feed on pea crops.

Late summer to fall

Adult weevils fly and migrate to their overwintering sites.

Sources: 1.“Pea Leaf Weevil,” Agri-Facts, Alberta Agriculture, 20142. “Pea Leaf Weevil,” Pest Fact Sheet, Montana State University, 2016


Outbreak factorsSpring weather conditions have a significant effect on the timing and severity of pea leaf weevil damage.1,2

Outbreak factor Result

Temperature Pea leaf weevils will arrive in fields early if warm conditions (above 20°C) persist for more than a few days in late April or early May, resulting in higher yield loss. In years when cool weather persists, the arrival of pea leaf weevils can be much later, and the yield impact less serious.

Moisture Dry years make plants more susceptible to the pea leaf weevil. In wetter years there is more nitrogen available to the plant, making it less susceptible to the pest.

Sources: 1.“Pea Leaf Weevil,” Agri-Facts, Alberta Agriculture, 20142.“Pea Leaf Weevil,” Grainews, May 17, 2016


Affected areasFirst spotted in Alberta in 2000, pea leaf weevil is now a serious pest in southern Alberta and southern Saskatchewan. In recent years it has been sighted as far north as Athabasca, Alberta.

The map below displays the incidence of pea leaf weevil in 2018, as monitored by the government of Alberta. Officials advise that central Alberta is a transitional area where pea leaf weevil incidence has worsened in recent years.

Pea leaf weevil in Alberta - 2018

Source: Alberta Agriculture, Food and Rural Development, 2018

Edmonton Lloydminster

Red Deer

Calgary

Lethbridge

Medicine Hat

>0 – 1 >1 – 3 >3 – 9>9 – 27>27

0

Average notches per plant


0 – 1 >1 – 3 >3 – 9>9 – 27>27

While pea leaf weevil populations were low in 2018, the pest’s overall spread and intensity have been on the rise for several years. Alberta Agriculture and Forestry specialist Scott Meers cautions against interpreting low presence as a reduced need to apply seed treatment, as populations have been known to rebound quickly.


Affected areasPea leaf weevil has been expanding to the north and east in Saskatchewan the past several years.

KindersleyOutlook Watrous

Humboldt

Melfort Tisdale

Estevan

Melville

Weyburn

Moose Jaw

Regina

Prince Albert

Lloydminster

Saskatoon

Swift Current

North Battleford

Meadow Lake

Yorkton

142

410

288

167

46

75

104 103

134

164165

135

105

316

283

194

225

256

1011

102 101

340

490

37

8 7

38

368

307

367

35

245

304

333 331

169

40 39

66

318

232

273

107

337

282 280 275

70

435

305

464

310

398

108

131

319

128

335

166

7379

312

152

92 91

487

456

138141

274

127

372

230

36

260

351

106

281

224 215

284

315

491

397

122

469

313

42

286287

317

2

9798

346

18

371

334

6

381

411

76

96

7172

132

121

6874

99

129

279

69

226

369

34

246

151

121

217 214 213

19

4933

338339

3132

321 320

257

229

440

253254

61

252

349

185

488

376

4

78

467

168

163

133

401

130

341342

136

350

380

219

123

171

110

125126

183

153

404

429

186

109

139

460

187

502

434

458

63

428

157

322309

64

51

124

17

400

155156

241

498

193

223

402

436

459

497

303

292

336

276

430

222

379

520

184

394

100

248

377

472

442

4443

162

501

45

471

555

494

154

216

190

468

191

345

366

395

314

218

486

93

588

9

403

439

231

9495

244261

137

437

111

561

399

622

211

181

457

373

427

344

277

247

271

259

228

77

382

352

521

406

158

405

250251

470

370

426

255

308

499

343

65

496

3

189

243

466

160

301

409

438

221 220

347

378

493

461

431

463

Geomatics Services, Ministry of Agriculture

Data Source: Survey data - Agriculture Knowledge Centre and Crops Branch IDW interpolation (power 2.5, fixed radius 300 km)Collaboration with:

© 2018 Government of Saskatchewan

Projection: UTM Zone 13 Datum: NAD83

0 50 100 150 20025

Kilometers

1:3,200,000

September 24, 2018

NOTE: Since techniques used to smooth the transition between zones can affect the values in localized areas,this map should be used for regional analysis only.

285290

161 159

67

5

Pea leaf weevil in Saskatchewan - 2018

Source: Government of Saskatchewan, Agriculture and Knowledge Centre and Crops Branch, 2018

Edmonton Lloydminster

Red Deer

Calgary

Lethbridge

Medicine Hat

>0 – 1 >1 – 3 >3 – 9>9 – 27>27

0



0 – 1 >1 – 3 >3 – 9>9 – 27>27


What’s at stake?High pea leaf weevil populations can destroy up to 90 percent of the root nodules. Larval feeding on the nitrogen-fixing root nodules (Rhiozobium) of the plant can result in:

• Significant yield losses • Weaker plants that are less drought

tolerant and produce less seedAdult feeding on the leaves and growing point of seedlings can result in:

• Adult feeding on the leaves and growing point of seedlings can result in economic losses due to reduced yield. • Plants can typically withstand 50 percent

defoliation without the damage impacting yields. The difficult-to-see larval feeding on nodules is where the major losses occur.

Root nodule damage caused by the pea leaf weevil larvae

Leaf damage caused by the adult pea leaf weevil


Management practices1. Plant early to maximize yields and

potentially avoid weevil damage in colder temperatures.

2. No-till cropping systems, integrated pest management systems and good crop rotations are recommended.

3. Registered seed treatments are recommended as your first line of defense. Not only do seed treatments protect against adults feeding on the foliage but they also delay and reduce egg-laying, preventing larvae feeding on Rhizobium nodules.

4. Trap crops can be planted along field borders in the fall or early spring. If warranted, spray trap crops with a registered insecticide to control pea leaf weevils before they move into the main crop.

5. Scout for pea leaf weevils as soon as peas and faba beans emerge and continue up to the six-node growth stage.


Management practices6. Foliar applications of insecticide are

recommended at the two- to three-node stage when one or more feeding notches appear in three out of 10 seedlings. If feeding damage occurs only on the lower leaves and not on the clam leaf, the weevil is no longer a threat to the crop.

Source: Alberta Agriculture and Forestry


Scouting • Begin scouting as soon as the plants emerge, and continue up to the six-leaf stage. Eggs laid after this period don’t affect yield.

• Pea leaf weevil is not an easy insect to spot as it ‘plays dead’ and drops to the ground on approach. Evidence of its presence comes from crescent-shaped notches on pea leaves.

• Economic threshold for foliar application: When one or more crescent-shaped notches appear on the clam leaf (most recently emerged leaves) in 30 percent of pea seedlings (three out of every 10 plants along a seeded row).

There is no economic threshold established for faba beans


ScoutingAssessing pressure in peasLook at 10 adjacent seedlings in 10 areas of the field. Count what proportion of the seedlings have damage on the clam leaf. Calculate the average damage for all 10 areas. Make sure to select five areas on the edge of the field and five areas at least 30 metres into the field.


Watch your pulse crops grow faster and stronger

Cruiser Maxx® Vibrance® Pulses seed treatment combines an effective insecticide with three fungicides to protect your pulse crops. Plus, Cruiser Maxx Vibrance Pulses delivers Rhizoctonia control as well as:

• The broad-spectrum seed- and soil-borne disease protection of Vibrance Maxx plus the early-season insect protection of Cruiser® 5FS insecticide

• Improved yield potential due to better plant stands, root systems, uniformity and overall plant health

• Contact and systemic activity that protects growing seedlings from both insects and diseases

• Compatibility with Rhizobium-based inoculants and seed safety

(Check inoculant suppliers of Rhizobium for details on compatibility)


How does it work? • Moves systemically through the plant as it grows • When the adult pea leaf weevil feeds on the new leaves, it ingests the active ingredient, thiamethoxam

• The insect will stop feeding and delay egg laying. This greatly reduces the number of larvae feeding on nodules

Application tips • May be applied on-farm or by commercial treaters using closed transfer (including closed mixing, loading, calibrating, and closed treatment equipment)


Use ratesCruiser Maxx Vibrance Pulses can be applied on-farm, provided a closed-system treater* is used, or by commercial seed treaters:• Cruiser 5FS @ 50 mL/100 kg of seed• Vibrance Maxx @ 335 mL/100 kg of seed (Apron Maxx® RTA @ 325 mL/100 kg of seed and Vibrance 500FS @ 10 mL/100 kg of seed)or• Cruiser 5FS @ 50 mL/100 kg of seed• Vibrance Maxx RFC @ 100 mL/100 kg of seed• Add water to create slurry volume of 325 mL/100 kg of seed

* Cruiser Maxx Vibrance Pulses must be applied using a closed-system seed treater. Please contact your local Syngenta Representative for further information.


Why use a seed treatment? • Insect pests can severely limit growing

success. The best way to protect nodulation in fields infested with pea leaf weevil is with a seed treatment

• Alberta Agriculture reports research has shown seed treatment is much more effective in decreasing losses from pea leaf weevil than foliar treatment.

Refer to product label for a complete list of pests, application timing, rates and directions for use.


Matador® foliar insecticide will protect your crop by controlling pea leaf weevil on contact

• Works on contact and through ingestion for up to seven days

• Fast-acting activity on adult pea leaf weevils • Registered for ground and aerial application in field peas and faba beans

Application timing • Make first application after plant emergence but prior to the five- to six-node stage

• Apply while adults are still present on the plants, before egg laying begins

Application tips • Recommended rate for pea leaf weevil is 34 mL/ac

• For best results, apply Matador in the early morning, before temperatures rise, and in the evening, after the heat of day

• Temperature must be warm enough for insects to be active at the time of application


Packaging • One jug treats 111 acres when applied at 34 mL/ac

Water volume • Ground: 40-80 L/ac (10-20 gal/ac) • Air: 4-16 L/ac (1-5 gal/ac)

Pre-harvest interval • Do not apply within 21 days of harvest for dry peas

Refer to product label for a complete list of pests, application timing, rates and directions for use.


Voliam Xpress® foliar insecticide will provide both rapid knockdown and long- lasting residual control of pea leaf weevil

• Works on contact and through ingestion • Initial and residual control is contingent upon thorough crop coverage

Application timing In pulses:

• Apply no later than when the first feeding is seen on foliage. Reapply after seven days depending on the presence of significant populations as determined by local monitoring

Packaging • Case: 4 x 3.78 L (treats 40 ac/jug or 160 ac/

case at the standard rate for most registered pests)

Water volume • Ground: minimum 10–20 gal/ac (100–200 L/ha)• Aerial: 4 gal/ac (40 L/ha)

For more information, visit Syngenta.ca or contact our Customer Interaction Centre at 1-87-SYNGENTA (1-877-964-3682).

Always read and follow label directions. Cruiser Maxx Vibrance Pulses is an on-seed application of (i) Cruiser 5FS Seed Treatment insecticide; (ii) Apron Maxx® RTA Seed Treatment fungicide or Apron Maxx RFC Seed Treatment fungicide and (iii) Vibrance 500FS Seed Treatment fungicide. Apron Maxx®, Cruiser®, Cruiser Maxx®, Matador®, RTA®, Vibrance®, Voliam Xpress® and the Syngenta logo are trademarks of a Syngenta Group Company. © 2018 Syngenta.

Documents

The Pea Leaf Weevil Management Guide · The map below displays the incidence of pea leaf weevil in 2018, as monitored by the government of Alberta. Officials advise that central Alberta