Ministry Update July 20, 2018 re: ArmyWorm & Rootworm

True Armyworm:  corn root damge by rootworm July        corn trap and beetles July        true armyworm trap moth and larvae

  • We have been monitoring for adult moths with pheromone traps in the Fraser Valley and on Vancouver Island from early May onwards.  You may see our green bucket traps or possibly wing traps (flat white sticky traps) around, along fence lines or field edges.  The traps are checked weekly and any armyworms caught are recorded, and kept for further analysis.
  • So far, we have caught a few armyworm moths on Vancouver island, and only three moth in Matsqui.  This number of moths is not of concern at this point.

·         Field scouting in June and July: we have had some reports (and photos) of caterpillars in grass hay fields in the Fraser valley and Cowichan valley, however, there wasn’t any significant damage to the crops and the caterpillars seemed to have moved on—we haven’t been able to collect any to confirm species identification.

 

Corn Rootworm: 

  • So far, this pest is only known to be present in the Fraser Valley of BC, with the highest numbers from Abbotsford to Rosedale/east of Chilliwack.
  • Please watch for any sign of this insect in other corn growing regions of BC (Vancouver Island, Okanagan, etc).
  • Some yellow sticky traps are now set up in the Comox/Courtenay area (July 19) to watch for beetles.

Fraser Valley:

  • Yellow sticky traps are now set up throughout the Fraser valley (July 9 onwards) along the edges of forage and sweet corn fields. Traps are set in similar locations as last year.
  • Any corn roots damaged by corn rootworm larvae will be evident now: infested corn plants may look weak, unthrifty, drought stressed, or may be tipping over, lodging, or ‘goose-necking’. Fields that are infested will have uneven growth.
  • The yellow and black adult beetles are now beginning to fly in some fields (July 8-13, Rosedale, Sumas).  Flight is expected to continue for the next few weeks, with the peak flight and beetle activity being late July to mid August.
  • If you are worried about pollination or cob contamination in sweet corn, foliar spray of beetles can be done.   If you have questions about this please contact Susan or Tracy at the Ministry.
    •  Spraying beetles will not help with the root damage or remove the need to rotate fields or use at-plant insecticide treatments (i.e. Force).
  • Fields that are Bt-traited corn  (stacked, pyramid) seem to be holding up well, and resisting the rootworm infestations.

·         ‘Refuge’ corn plants, those that are not Bt-traited corn, and are not treated with at-plant insecticide (Force), are getting sufficiently damaged by larvae.

·         Reports are that fields treated with Force are looking fine.

·          Please let Susan or Tracy know if you see any fields that are showing damage that were treated with Force or planted with Bt-traited corn.  Rootworm has developed resistance to control tools elsewhere so we need to continuously watch for this here in BC.

  • Information on corn rootworm can be found on the Farmwest.com  website.

Over the summer, you might see summer staff out there checking traps and looking at fields, they will be in grey Ministry cars with BC logos on the sides, and names are Matt and Ryan.

Additionally we are getting a bit of help with trapping and checking fields from the Pacific Field Corn Association and the University of the Fraser Valley summer staff, Emily, and her supervisor Dr. Renee Prasad.  On Vancouver Island, Graeme, Jill, and Heather S are checking traps and reporting any detections.

We will send out notices as needed over the summer. Please share this information as needed.

Thank you for your involvement in this initiative, and please contact Susan or Tracy if you have questions.

Tracy Hueppelsheuser

British Columbia Ministry of Agriculture

1767 Angus Campbell Road,

Abbotsford, British Columbia, V3G 2M3

Phone: 604-556-3031

[email protected]

Susan Smith

Industry Specialist, Field Vegetables

British Columbia Ministry of Agriculture

Phone:  604-556-3087

Cell:  604-226-5168

Email:  [email protected]