You Are Here: Management Updates 2005 Archive July 15, 2005

Date: July 15, 2005
Category: Insects
Subject: White Grubs, Annual Bluegrass (Hyperodes) Weevil

White grubs
We have been looking at samples collected from near New York City, looking for annual bluegrass weevils. But in addition to the weevils, we have been finding eggs of oriental beetles. This serves as a reminder that most of the grub species (oriental beetles, Japanese beetles, European chafers, asiatic garden beetles, and for some, northern masked chafers) are active now. The adults have been flying for a week or more, and some are already laying eggs. Recent studies in cranberries have found that oriental beetle females are ready to lay eggs relatively soon after they emerge and mate. The take home message is that egg-laying has indeed begun in southern New England, and may already be underway in central New England as well.

If the weather patterns we have seen so far continue this summer, you might find that beetles choose to lay eggs in places that are a little higher and drier than you usually see them. In many areas heavy rains have left soils moist, and females will try to avoid laying eggs in saturated soils. Of course, the weather might change and things might start to dry out - but in the meantime, keep an eye on the higher and usually drier sites as potential places for grub activity.

Annual bluegrass (Hyperodes) weevil update
We are finding a little bit of everything in our samples from Westchester County, some tiny larvae (barely visible even with a large magnifying glass, medium larvae, large larvae, pupae, and adults. I think they are just finishing the second generation in that area (just north of New York City). Closer to home, many superintendents are reporting that they are seeing large numbers of adults on the surface. They have begun to lay eggs, and you should start seeing evidence of small or medium larvae very soon.

Submitted by: Dr. Pat Vittum

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