You Are Here: Management Updates 2005 Archive April 20, 2005

Date: April 20, 2005
Category: Insects
Subject: Annual Bluegrass (Hyperodes) Weevils, White Grubs

Hyperodes weevils
As we enter this extended period of unseasonably warm weather in the Northeast, we have been receiving many phone calls from golf course superintendents wondering about the annual bluegrass weevil. We have reason to believe the weevils survived the winter just fine, and the adults appear to be on the move in many areas.

Previous "recommendations" were based on making an insecticide application when Forsythia reached full bloom. But more recently, Paul Heller (at Penn State) and I have found that applications made in the period a week or two after Forsythia full bloom to dogwood full bloom work very well. (Paul uses the "serviceberry" as an indicator plant, whereas I suggest that applications not be made until Forsythia bushes are showing significant green as the leaves begin to open). Based on telephone reports from people throughout the Northeast, I would guess that much of southern New Jersey is in the period where applications could be made this week. The courses in Westchester County, NY and points north are probably looking at next week. Courses in most of Massachusetts should be making applications during the first week of May, unless they have local spots that are unusually warm. In general Paul and I have found that it is better to go a little bit "late" rather than going a bit "early", even though the warm temperatures sometimes make folks get a little anxious.

The spring application should be chlorpyrifos (Dursban™) or a pyrethroid and should be watered in lightly. Some of the pyrethroids that are available are: bifenthrin (Talstar™), cyfluthrin (Tempo™), deltamethrin (Deltagard™), and lambda-cyhalothrin (Battle™, Scimitar™).

White grubs
Most grubs should be back in the root zones feeding at this point. Now would be a good time to monitor your areas to see which species are active. Keep in mind that European chafers and oriental beetles have been expanding steadily, so many turf managers are now dealing with two, three, or even four pest species in a given location. So get out and take a look - figure out which species you have. It will have a direct bearing on your options later in the season.

If you would like help identifying the grub species and are willing to send us at least 50 grubs from each location, contact us. We will give you instructions on shipping grubs to us, and we will do the identifications for you. This information helps us to refine our understanding of where each species is active now. So contact us either by e-mail (pvittum@ent.umass.edu) or by phone (413-545-0268). Don't send us any grubs without contacting us first!!!

Submitted by: Dr. Pat Vittum

DISCLAIMER - As always, it is the responsibility of the applicator to verify the registration status of any pesticide BEFORE applying it. Different states have different regulations as well. The author and the University of Massachusetts are not liable for any consequences of any pesticide "recommendations". Mention of any trade name is not to be considered endorsement of a product.

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