Turf Management Blog

---

During an Intelligro™ luncheon hosted at the Golf Industry Show (GIS), Dr. Ben McGraw, Ph.D., Pennsylvania State University tackled a topic that is top of mind for many Superintendents. The Annual Bluegrass Weevil (ABW) was the uninvited guest of honor, as it continues to be, for many golf courses across eastern North America. With a ravenous appetite for Poa annua and Creeping Bentgrass, this problematic pest preys on high-valued turfgrass areas such as fairways and greens. The damage is severe and costly.

Say goodbye to synthetics
Traditionally, there has been a heavy and expensive reliance on synthetic insecticides. According to a recently published survey, superintendents in the Northeast average nearly 4 insecticide applications per year (with some making as many as 12 applications) costing around $9,270 per year– that’s three times the national average of insecticide use! For many years, pyrethroids were the go-to for a cheap and effective fix. However, repeated applications have not only resulted in resistance for some ABW populations but a decrease in susceptibility to non-pyrethroid insecticides in populations with elevated pyrethroid resistance. 

New research, new approach
ABW research, driven by positive feedback from Superintendents, initially started in the year 2000 and continues today.
Dr. Ben McGraw looked at a variety of factors that impacted ABW control and conducted numerous lab and in-field trials with a focus on CIVITAS TURF DEFENSE™. Through trial and error, along with painstaking observation, he looked at the biology and life cycle of ABW, management practices and challenges as well as the opportunity for future work.
As a result, this early research shows promising signs towards a working ABW control blueprint using CIVITAS TURF DEFENSE™.

1. Adults only – Knowing the lifecycle stage in which ABW are most vulnerable is half the battle. Focus on adult control, as larvae will remain protected from the product within the plant. Too late, and the adults will have already had a chance to spread their eggs. Ideally, you want to target the adults as they begin moving on to short-turf areas in spring. 
2. Be direct – Lab comparisons revealed that direct contact between insects and CIVITAS TURF DEFENSE™ is critical.  High levels of control were observed within 3-72 hours.  Little to no residual activity was observed in the field when CIVITAS TURF DEFENSE™ was allowed to dry on the foliage prior to introducing insects. It was also found that there was no mortality through ingestion.
3. Oil works – CIVITAS TURF DEFENSE™ is derived from 99.9% pure white mineral oil. With over 100 years of studying oils and soaps, there has never been any documented resistance to an oil. CIVITAS TURF DEFENSE™ is found in multiple regions inside the insect’s body soon after application, which may allow water to rush into the insect, and compromise their breathing system.
4. Timing is everything – For effective application, understanding insect behavior is key. A 2016 field study with Ben Czyzewski focused on time, temperature and daylight to see what conditions impacted ABW behavior on top of the canopy and their susceptibility to removal. High-tech cameras monitored movement over a 24 hr period.  Combined observations over three spring dates revealed maximum canopy activity occurs between 14-18˚C (57-64˚F).
5. The wetter, the better – High carrier volume, soil moisture and rainfall all contributed to improved control in field and laboratory trials. While there is an effect of rate, there was a larger effect of carrier volume in most studies. Generally, it was moisture that made the difference. In response to these findings it is recommended, if possible, to water before and after a treatment.

ABW research has come a long way but there is always more to discover.

For more information on ABW control or CIVITAS TURF DEFENSE™ talk to one of the Intelligro technical managers, or contact Matthew.Weaver@petrocanadalsp.com.

Best of luck for a great spring season!