You Are Here: Management Updates 2001 Archive April 30, 2001

Date: April 30, 2001
Category: Insects
Subject: Hyperodes Weevils, White Grubs, Black Turfgrass Ataenius, Ants

Now that spring is finally arriving in full color, it is time to think about the turf insects that are out and about. ANNUAL BLUEGRASS WEEVILS have been on the move for a while now. We are sampling overwintering sites (collecting leaf litter and floating weevils out) and fairways (vacuuming) at several locations, and we know that the weevils left their overwintering sites in the metropolitan New York area at least a couple weeks ago. They are on the fairways, presumably mating and preparing to lay eggs. Forsythia in Westchester County was in full bloom about ten days ago, and is already in that nebulous "half green/half gold" stage now. Further north and further inland, weevils are still on the move, heading toward the fairways, greens, and collars. Forsythia in Amherst has been in peak color for the last week or so.

Now is a prime time to treat for annual bluegrass weevils on golf courses that have a history of problems, especially those courses in southern New England. Use a material that stays in the thatch (e.g., Dursban™ or a synthetic pyrethroid) and water in lightly. Golf courses in the metropolitan area probably should aim to have your materials in place by the end of next week (i.e., 10 May). Areas further north or inland have a little more time.

WHITE GRUBS - With the uncommonly dry conditions of the last three weeks, some turf areas are showing stress that is in part related to grub feeding activity. In most cases, there is little gained by applying an insecticide at this point. Turf managers in eastern Massachusetts may well be dealing with European chafer grubs, which will feed for only a few more weeks before they prepare to pupate. The only insecticide that would provide any relief at this point would be a spot application of Proxol™ or Dylox™, but for most folks, this is not economically feasible.

Remember that the "season long control" materials, such as imidacloprid (Merit™) and halofenozide (Mach2™) have little or no effect on the spring grubs. If you wish to use something like Merit™ for white grub control, we generally recommend that you delay application until at least mid June. That way more of the product is still present when the grubs become active in mid August. (Don't wait too long, though - the application needs to be in place by early August in most locations.) If you are dealing with European chafers, any applications should be made about two weeks earlier than described here.

BLACK TURFGRASS ATAENIUS adults will be on the move during this warm weather. Watch for them in the clippings when emptying baskets, especially from greens. It seems that relatively few golf course superintendents are reporting problems from this insect. This may be in part because Meritª applications in previous years have been providing some relief.

TURFGRASS ANTS are becoming active at this time. In areas where ant activity has been excessive in previous years, you might consider using a turf product with ants on the label. The trick seems to be to make the first application as soon as you see the first activity, which may well be this week for much of southern New England.

- Submitted by: Dr. Pat Vittum