Alberta, Saskatchewan and Manitoba will be doing bertha armyworm and diamondback moth surveys again in 2018.
Diamondback moth traps are sentry traps to show the presence/absence of adults, but there isn’t very good correlation of adult catch and larval pressure. These traps cannot indicate an immediate threat in specific fields.
Bertha armyworm traps catch adults (moths). These traps are an extremely valuable early warning system, giving an indication of potential pressures from larvae.
These monitoring programs help predict risk on a regional basis, but cannot predict risk at the field level. Capture of a large number of moths in a particular trap does not necessarily indicate that larval populations will be high in the field containing the trap. Trap catches cannot be used to make management decisions for the field with the trap.
For example, for bertha armyworm the stage of canola can determine how attractive the field is to egg-laying females. The catch of male moths in the traps could be high but level of eggs laid in the field low. Several high traps counts within a region can indicate a potentially higher risk in a region, which will hopefully encourage increased scouting for larvae in these regions.
To put up a trap and help with the monitoring program (including trap checking), please contact your provincial entomologist:
Alberta: Email Shelley Barkley at Shelley.Barkley@gov.ab.ca or Scott Meers at Scott.Meers@gov.ab.ca
Saskatchewan: Email James Tansey at email@example.com.
Manitoba: Email John Gavloski at john.Gavloski@gov.mb.ca.
Provincial entomologists also monitor for pests in other crops. For example, Alberta is also looking for pre-approved permission to sample pea fields for pea leaf weevil and wheat fields for sawfly and midge. If you’re interested in volunteering fields, please contact Shelley or Scott at the emails above.