You Are Here: Management Updates 2002 Archive June 7, 2002

Date: June 7, 2002
Category: Insects
Subject: Hyperodes Weevils on the Move

We have had numerous telephone calls this week, and it seems the annual bluegrass weevil ('Hyperodes weevil') is becoming active throughout southern New England. We are analyzing plugs collected from just north of New York City and are finding many medium and large larvae, as well as a few pupae. From telephone descriptions, it appears that superintendents in southern New England are just beginning to see the wilting that follows initial larval feeding. For those of you in Vermont, New Hampshire, and Maine, consider this your "heads up" - you undoubtedly will be next to see the wilt.

If a quick inspection reveals small white larvae with brown heads (they resemble grains of rice), you may get some relief by spot treating the affected areas with trichlorfon (Dylox). (If most of the insects are kind of diamond shaped and do NOT have brown heads, they have already moved on to the pupa stage, and nothing will work at this point.) This should NOT be considered a formal recommendation in any way but it may provide relief for some.

Our experience has been that the synthetic pyrethroids do NOT get down to the larvae at this point, but pyrethroids could be an option three or four weeks from now when targeting the adults of the next generation. Water very lightly - just enough to move the material off the blades. There are no guarantees, and note that the weevil is not on the label of some formulations of trichlorfon. In some states (e.g., New York), that precludes a superintendent from using it for this purpose, while in other states (e.g., Massachusetts), as long as the site is labeled, the application is considered legal even if the target insect is not listed. Also note that superintendents in Maine are out of luck - Dylox is not cleared for use under any circumstances.

We will keep you posted on further developments, and will make projections for timing of application for the second generation as that time approaches (probably the last week of June or first week of July for the folks in the metropolitan area, slightly later further north - as a first approximation). As they say in show business, "stay tuned"!

- Submitted by: Dr. Pat Vittum