You Are Here: Management Updates 1999 Archive May 10, 1999

Date: May 10, 1999
Category: Insects
Subject: Hyperodes Weevils, Black Turfgrass Ataenius, White Grubs

The insects are beginning to move - most white grub species have been feeding actively for a few weeks now, and we are getting numerous calls about European chafers and resulting skunk damage, especially in areas where soils are very dry. There is little that can be done for grubs at this point other than to manage the damage - roll turf, overseed where possible, and keep well watered. Most grubs will stop feeding within the next two to four weeks in preparation for pupation in June - small comfort, no doubt.

Annual bluegrass weevils (Hyperodes weevils) have moved out from their overwintering sites. Dissections by my graduate student, Nikki Rothwell, confirm that weevils in areas south of Hartford have begun to lay eggs, so we can expect to start seeing tiny larvae within a week. Large larvae should show up just about on schedule - late May or early June in metropolitan New York, first or second week of June in southern New England, and mid June in southern New Hampshire. We are nearing the end of the treatment window for the spring generation - most materials should be in place by the time dogwood is in full bloom, and the dogwoods in Amherst finally began to "pop" this week following the rain.

We have not received any reports of black turfgrass ataenius beetles, but I suspect they are on the move and preparing to lay eggs soon. With the widespread use of Merit over the past two or three years, many superintendents have not encountered problems with the BTA, but if those superintendents are using other materials this year, they should be on the lookout for grub activity in early June. Grubs will be tiny (less than 1/8 inch long) and often have quite a gray color, so they blend into the dark soil well. Typical grub materials can be very effective if applied when the horse chestnut is in full bloom (normally early June in western Massachusetts).

- Submitted by: Dr. Pat Vittum