Sorry, but I just had to put that in the title line. Annual bluegrass weevil migration is on golf superintendents’ minds right now. It is early days still. We have not met the GDD requirement in the Guelph area yet for migration to start (28 GDD base 10 degrees C or 50 GDD base 50 degrees F).
The current thinking on the application of adulticides to control the annual bluegrass weevil adults as they migrate into the turf from their overwintering sites is to apply when the forsythia are half green/half gold. Forsythia have not even started to bloom yet. The problem with trying to target the adults is that there is often a bimodal migration (two different peaks at two different times) and that makes it hard to know when to apply against the adults. The second strategy is to target the early instar larva with a larvaecide. The products that can be used for this application in Ontario include clothianidin and chlorantraniliprole. They are systemic in the turf plant and more persistent than the adulticides so the timing is not as crucial.
The key thing at this point is to monitor for the adults. This can be done with a pitfall trap, a soap flush or a vaccuum. Knowing what the ABW’s are doing on your course and where they are is the best recipe for success.
There is a great webinar on the GCSAA website by Dr. Dan Peck that will explain all there is to know about the annual bluegrass weevil. It is worth investing an hour of your time. It can be found at http://www.gcsaa.tv/webinars/sponsored/view.php?id=196
Also, I will keep posting on the progress of annual bluegrass weevil over the next month to help you better target this pest.