Root, bulb, leafy and brassica vegetable pest report – 19 June 2013

See below for the degree days accumulated from April 1st until June 18th, 2013.These values are provided as guidelines only. Local environments, soil type, field history, etc. are likely to influence activity of these pests.

Onion maggot fly activity peaked last week in the Holland Marsh (reported on 13 June 2013).  For all areas, accumulated degree days indicate emergence of first generation carrot rust fly adults, if resident populations are present. Carrot rust fly counts at the Muck Crops Research Station in the Holland Marsh reached threshold 0.2 flies/trap/day (treatment threshold is 0.1 and 0.2 flies/trap/day for fresh market and processing carrots, respectively). If resident populations are present, degree days indicate 90% oviposition by carrot weevil in all areas except Wellington. Tarnished plant bugs have likely emerged in all areas; however, the Muck Crops Research Station scouts have not seen tarnished plant bugs on celery in the Holland Marsh yet. I’ve seen tarnished plant bug on sticky traps as by-catch though. Overwintering leafhopper eggs have likely started to hatch in all areas. Local leafhopper adults will likely start emerging in Bradford/Holland Marsh, London, Thedford, Delhi and Ridgetown over the next 5 to 10 days. Very low counts of aster leafhoppers have been reported in the Holland Marsh.

Onion thrips have been seen on onions in the Holland Marsh. Be sure to scout for thrips.

Area

Onion Maggot (base 4)

Cabbage Maggot (base 6)

Carrot Rust Fly (base 3)

Carrot Weevil (base 7)

As of

Bradford/Holland Marsh*

645.1

n/a

713.4

457.9

18/06/2013
London

657.8

528.5

726.1

470.3

18/06/2013
Wellington

573.7

452.6

639.6

396.9

18/06/2013
Windsor

787.1

649.7

859.7

585

18/06/2013
Thedford

638.7

513.2

706.8

458.2

18/06/2013
Delhi

631.8

507

699.3

449.2

18/06/2013
Ridgetown

661.1

534.3

729.8

473.9

18/06/2013

 

Area

Tarnished Plant Bug (base 12)

Leafhopper (base 9)

GDD (base 5)

As of

Bradford/Holland Marsh*

209.9

350.0

580.4

18/06/2013
London

217.6

361.6

591.6

18/06/2013
Wellington

161.0

292.9

510.8

18/06/2013
Windsor

305

464.4

717.1

18/06/2013
Thedford

213

352.8

573.4

18/06/2013
Delhi

200.9

340.1

567.5

18/06/2013
Ridgetown

226.9

366.8

596.1

18/06/2013

Data provided by Environment Canada.

*Data provided by Muck Crops Research Station, University of Guelph.

Degree day model information for pests 

Thresholds

1st Generation

2nd Generation

3rd Generation

Onion Maggot

210

1025

1772

Cabbage Maggot

314-398

847-960

1446-1604

Carrot Rust Fly

329 – 395

1399-1711

n/a

Carrot Weevil

138-156 (first egg-laying)
455 (90% of eggs laid)

No model available

n/a

Tarnished Plant Bug

40

n/a

n/a

Aster Leafhopper

128 (overwintering egg hatch)

390 (local adult emergence)

n/a

n/a

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