Weary of Weevils

Over the past several years, the Annual Bluegrass Weevil has become the toughest insect we have to battle on the golf course.  With a high percentage of Poa on the greens, we are constantly monitoring for weevils, particularly in the collars.  There are a number of generations of weevils throughout the growing season, and it often feels as if the war on weevils will never end.

As the name implies, these weevils prefer Poa Annua over Bentgrass.  However, as a person might prefer filet over hamburger, when there's nothing else to munch on, the weevils will cause damage to Bentgrass. 

We've heard about this for some time, and have seen pictures of Bent injury, but this week was the first time we've experienced it at Laurel Creek.  With little Poa in the fairways, they have gone after Bentgrass.

While the turf in the picture below may not exactly look devastated, close inspection of the flagged mound shows signs of thinning.


Digging into the turf, the cause of the trouble is found--weevil larvae.



 

We pulled several plugs and placed them in a salt solution, causing the larvae to leave the turf and float to the surface.  This area had close to 100 larvae per square foot.  Bentgrass is much more tolerant of weevil activity than Poa, and we certainly don't anticipate any widespread damage at this time of the year.  However, going forward, we know we'll have to keep a watchful eye on the tees and fairways for wicked weevils.