Friday, September 13, 2013

Not More Weevils!

After a few warm days this week, it looks like we might be heading into some welcome fall weather.  Cooler temperatures will give us some good root-growing weather for the turf, and fewer pests to be concerned least that's how it's supposed to work.

For several years we've been battling the Annual Bluegrass Weevil, which favors damaging Poa Annua (given their name, that makes sense) over Bentgrass, and usually lays its eggs in collar height turf.  These little guys are now considered by many to be the greatest insect pest in the northeast.  Their first damage often shows itself in late spring, and by this time of year, there are no longer well-defined generations of the weevils.  That is, you can find them in all phases of development--eggs, larvae, pupae, and adults--making control especially difficult.

As mentioned, they typically cause problems on collar height turf, leaving the putting surface alone.  However, it looks like several of the weevils overcame the challenges of egg-laying in greens height turf, as we're now finding larvae in the middle of greens.  Why would this happen now?

It's quite possible that the days immediately following greens aerification gave the weevils the opportunity they were waiting for.  During that period we skip mowing for a couple of days and raise the height of cut, allowing adult weevils to happily traverse the putting surface without fear of a mower sweeping them up.

While it's unlikely that there will be a great deal of damage to the putting surface at this time of year, it still makes sense to treat for them.  After all, any weevils that are taken out now, won't be around to lay eggs in the spring.

The legless larvae are the size of a grain of rice.


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