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

Date: May 30, 2001
Category: Insects
Subject: Annual Bluegrass (Hyperodes) Weevils on the March!

Based on field samples we have collected from Westchester County, NY, and Hartford, CT, as well as conversations with superintendents from New Jersey, New York, and southern New England, the annual bluegrass weevils appear to be about a week AHEAD of the "schedule" we have seen in past years. Many superintendents are reporting visible damage, and many are seeing large larvae in significant numbers, especially in New Jersey, Long Island, and southeastern New York State.

Once a superintendent begins to notice the typical wilting symptoms, damage usually will intensify to yellow patches of annual bluegrass that gradually get bigger. The most severely affected areas will take on a water-soaked appearance. If heavy rain occurs during this period, large larvae (feeding in the crown of the plant) may float to the surface and float downstream in the puddled area, effectively spreading the infestation. Damage typically intensifies for about two weeks and then eventually slows down. However, weevil-feeding activity will persist for the rest of the growing season. If we have typical summer temperatures, we can expect to see three generations of larvae in the metropolitan area.

There is nothing labeled for annual bluegrass weevil larvae once they reach this stage of activity. Some superintendents have experimented with materials that are quick-acting and penetrate the thatch readily, but note that the materials that meet this description and are most readily available commercially are NOT labeled for that use.

We can see the whites of the weevils' eyes - and they have a nasty gleam!

- Submitted by: Dr. Pat Vittum