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Manitoba Insect & Disease Update – Issue 10: July 20, 2016

The Manitoba Insect and Disease Update is now posted at: http://www.gov.mb.ca/agriculture/crops/seasonal-reports/insect-report-archive/insect-report-2016-07-20.html

Some highlights from the update:

Insects:

  • Pea aphid levels are still a concern in some pea fields, although many fields will be getting to the stage where management would no longer be economical.
  • Aphid levels have dropped in many cereal fields where previously levels had been increasing. High levels of natural enemies have been noted in some of these fields, and some intense rains may have also contributed.
  • In some areas of Central and Southwest Manitoba, greater than 90% of the wheat midge are expected to have emerged. In many areas of Manitoba about 50 to 90% of wheat midge are expected to have emerged. A reminder that wheat that has already produced anthers is no longer susceptible to feeding by wheat midge. Even if adults are still active in these more advanced fields, the larvae will not feed on the grain.
  • Egg masses of European corn corer are starting to be noted in some fields of corn. So far there are no reports of high levels, but now is the time to be checking fields for the egg masses.
european-corn-borer-egg-masses

Figure 1. Egg masses of European corn borer.

Plant Pathogens:

  • Some infections of blackleg in canola and fusarium head blight in cereals have been reported.
  • A few cases of loose smut in barley were also reported.
  • Two positive identifications of Goss’s Wilt in corn were made. The positive identifications were made based on immunostrips and/or polymerase chain reaction (PCR) assays.

Submitted by: John Gavloski, Entomologist & Pratisara Bajracharya, Field Crop Pathologist, Manitoba Agriculture

Manitoba Agriculture website: www.manitoba.ca/agriculture
Manitoba Agriculture on Twitter: @MBGovAg
Manitoba Agriculture on YouTube: www.youtube.com/ManitobaAgriculture

 

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