Annual Bluegrass Weevil

Spring has sprung, and with the warmer temperatures comes the return of annual bluegrass weevils (ABW) to golf courses across the Northeast. The weevil currently seems to be the greatest insect challenge facing annual bluegrass golf courses in the region. Management programs continue to target the egg-laying adults that emerge in early spring, and the success of the management programs can be significantly influenced by the timing of the initial insecticide application. Justifiably, there also are concerns with ABW resistance to pyrethroid insecticides that have been used as contact controls against the adult insects.

Entomologists continue to work on management programs for the insect, and the body of information concerning the ABW’s biology, life-cycle, and control options is growing. Green Section agronomists have been encouraging golf course superintendents to install pitfall traps to monitor ABW activity more closely and accurately for several years. We hope this will help pinpoint emergence patterns of the insect to aid in control. This has never been more important. The insects can be controlled, but the key is to thoroughly understand where they are and what stage they are in.

The Richmond Linear Pitfall Trap is one tool being utilized for that purpose. The linear oriented trap, pictured in the diagram requires few materials, and can be made and installed quickly. A full- sized diagram and description can also be obtained by contacting one of our Green Section offices.

Mike Barton, of Burning Tree CC in Greenwich, Ct. is one of several superintendents working with Dr. Harry Niemczyk, Professor Emeritus from The Ohio State University, in collecting insect data and experimenting with different control options. When the ground is workable, the traps are installed to intercept adult weevils as they emerge from overwintering sites and move across rough areas. The traps should be checked daily for the presence of adults. Soil and air temperatures are measured and phenological observations are documented as well.

Clay Pedigo, superintendent at Oak Lane CC was introduced to these traps earlier this winter and also has incorporated their use on the golf course in Woodbridge, CT. Pedigo and Barton both found adults in traps as early as March 20. Without the traps, the early emergence may have been missed and the timing of their initial sprays less effective. Both superintendents foresee that closer monitoring will improve the efficacy of their spray programs and help them better manage this difficult insect. Pedigo has also received a number of positive comments from members who come across the traps in the field. The traps are a good communication tool that shows the staff is making every effort to improve the control programs and in doing so maximize their limited chemical budget.

The extent of winter injury is fully realized at this point in New England and in most (but not all) cases it is not as bad as we had initially feared. The moderate temperatures in March and the use of covers have allowed for an earlier than usual green-up and an indication of what is and is not alive. The worst of the damage is in the lowest green depressions or swales where all the turf is lost. The annual bluegrass that was injured further from the low areas seems to be recovering somewhat. Thus, the damage is more confined than has often been the case in the past. Hopefully, this will allow the recovery efforts to be focused on the smaller areas and hopefully reduce the time the greens are kept out of play. Seeding programs have been underway where it has been dry enough to do so. Unfortunately, it is likely that some seed has floated away with the torrential rains we have just experienced. The weekend forecast for warmth and sunshine is a welcomed one for those winter-damaged golf courses and should stimulate some much-needed growth!

The 2010 Rhode Island Turfgrass Foundation golf tournament is scheduled for April 27 at Agawam Hunt Club. The Rutgers Turfgrass Research Golf Classic is scheduled for May 3 at Fiddlers Elbow CC. We encourage you to attend these events to support the turf programs and enjoy a great day with your peers.