Degree days for root, bulb and leafy vegetable pests – 31 July 2011

In the Windsor area, degree days have accumulated past the threshold indicating emergence of the 3rd generation of cabbage maggot. Also in the Windsor area, emergence of the 3rd generation of adult onion maggot is expected in 4-5 days. Over the next couple days, enough degree days will have accumulated indicated emergence of the 2nd generation of carrot rust fly in the Wellington area.

Here are the degree days accumulated from April 1st until July 31st, 2011.

Area

Onion Maggot(base 4)

Cabbage Maggot(base 6)

Carrot Rust Fly (base 3)

Carrot Weevil (base 7)

Bradford/Holland Marsh*

1442.9

N/A

1560.7

N/A

Sarnia

1410.6

1197.8

1524.2

1097.6

London

1457

1237.9

1571.1

1131.6

Wellington

1259.7

1047.6

1369.5

944.7

Windsor

1673.8

1444.3

1792.8

1336.9

Area

Tarnished Plant Bug (base 12)

Leafhopper (base 9)

GDD (base 5)

Bradford/Holland Marsh*

642.9

911.9

1328.6

Sarnia

645.8

905.6

1302.1

London

652.1

928.1

1346.2

Wellington

500.9

752.3

1152.4

Windsor

846.9

1131.8

1556.5

* Data provided thanks to Muck Crops Research Station, Department of Plant Agriculture, University of Guelph

 Degree day information for pests

Degree Days

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
455 (90% oviposition)

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

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s