The extended cool temperatures of this spring have certainly delayed insect activity. I have not received any reports of new grub damage yet, but as temperatures rise this week, I suspect the grubs will too! So monitor any sites where turf seems to be a little thin from last fall, to determine whether grubs are part of the issue.
Meanwhile the annual bluegrass weevil (ABW) is off to a very slow start in southern New England. We are monitoring five sites for the Syngenta Weevil Trak program, and most of those sites had accumulated 10 degree days or less as of 22 April. That makes it the coolest spring we have tracked since 2009. Daffodils are just blooming in the Amherst area now, and some of the Forsythia in warmer locations are beginning to bloom, but it will be quite a while until we approach that "half green, half gold" stage that normally marks the time to apply an adulticide.
So for now we are in a holding pattern. Remember that the adults take a while to mature once they arrive on the short grass, so there is nothing to be gained by applying an adulticide early. Given that most of you should try to minimize the number of pyrethroid applications you make each year, try and get the best "bang for the buck" by waiting until Forsythia half green, half gold. At that point most of the weevils will have left their overwintering sites, but few of them will actually be mature enough to produce and lay eggs.
Submitted by: Dr. Pat Vittum
