You Are Here: Management Updates 2000 Archive April 13, 2000

Date: April 13, 2000
Category: Insects
Subject: White Grubs, Hyperodes Weevils, Chinch Bugs

The unusually warm weather during late March pushed many trees and shrubs to bloom earlier than normal but now we seem to be in a slightly cooler period. White grubs have returned to the root zone and are feeding in many parts of Massachusetts. Turf managers who saw grub feeding damage (or more likely, skunk or raccoon activity) in March probably are dealing with European chafers. Remember to check the identification section of the web page to sort out which species are most likely to be active in your location. Halofenozide (Mach 2) and imidacloprid (Merit) will NOT lower spring grub populations significantly. If you need to reduce those populations now, considerusing a fast acting product like trichlorfon (Dylox or Proxol). As always, remember to water it in - or let the spring showers help you.

Annual bluegrass weevil - Adult weevils are on the move from their overwintering sites in the metropolitan New York area and even as close as Hartford. If we continue with seasonal or slightly warmer than normal temperatures, we can expect that migration to flourish in Massachusetts within the next few days. Even though forsythia have been in bloom for several days, or even a week or two, in southern New England, we urge golf course superintendents to hold off on an insecticide application until soil temperatures have gotten above 50 degrees for several days. You might consider holding until forsythia are "half green, half gold" - in other words, the leaves are starting to expand and the old flowers are still hanging on.

Chinch bugs - Don't forget that many areas experienced very large chinch bug populations last summer. Drought-stressed areas that did not respond and recover in September may have been hammered by chinch bugs (or possibly by billbugs). In either case, consider monitoring for chinch bug activity during late April or early May - overwintering adults will be resuming their activity then. It will be a while before they start laying eggs, and damage would not be visible until July or August, but it can help to know whether the local population is "raging". (Keep in mind that the severe cold spell in January, when we did not have snow cover, may have killed some chinch bugs naturally.)

- Submitted by: Dr. Pat Vittum