Thursday, 2 June 2016

Weekly Update (June 1, 2016; Wk 05) - Cutworms

Cutworms (Noctuidae) – Reminder - Keep an eye on fields that are “slow” to emerge, are missing rows, include wilting or yellowing plants, have bare patches, or appear highly attractive to birds – these are areas warranting a closer look.  Plan to follow-up by walking these areas later in the day when some cutworm species move above-ground to feed.  Start to dig below the soil surface (1-5 cm deep) near the base of a symptomatic plant or the adjacent healthy plant.  If the plant is well-established, check within the crown in addition to the adjacent soil.  The culprits could be wireworms or cutworms.  

Several species of cutworms  can be present in fields.  They range in colour from shiny opaque, to tan, to brownish-red with chevron patterning.  Cutworm biology, species information, plus monitoring recommendations are available in the Prairie Pest Monitoring Network’s Cutworm Monitoring Protocol.  Also refer to Manitoba Agriculture and Rural Initiatives cutworm fact sheet which includes action and economic thresholds for cutworms in several crops. 

More information about cutworms can be found by accessing the pages from the new "Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and Field Guide".  View an excerpt of ONLY the Cutworm pages from the new "Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide".  The guide is available as a free downloadable document as both an English-enhanced or French-enhanced version.

For Manitobans....Last week's Insect Update includes great photos of dingy and redbacked cutworms plus monitoring tips which include how to discern these two species from one another.

For Saskatchewanians....Cutworms have been reported in several areas of the Province this spring. Affected crops include pea, lentil, barley and canola. If damage is significant and re-seeding is an option, seed first then spray an insecticide registered for cutworms in the applicable crop. Recommended economic thresholds for cutworms are:
   - 25 to 30 per cent stand reduction (canola)
   - 3 to 6 cutworms / square metre (wheat, barley, oats)
   - 2 to 3 cutworms / sq. metre (pea, lentil)
   - 4 to 5 / sq. metre (flax)

For Albertans..... Cutworms have been reported throughout the province the past week!  If you find cutworms, please consider using the Alberta Pest Surveillance Network’s “2016 Cutworm Reporting Tool”.  Once data entry occurs, your growers can view the live 2016 cutworm map.  A screen shot of the live map has been retrieved (01Jun2016) below for your reference and this week it includes additional reporting sites!