Feels like March! Cool and Wet, New Chicago Pests, and CDGA Turf Library
One step forward, two steps back? That has happened so far in April. Currently temperatures are more like March and this can create difficult decisions for golf course superintendents given early preventative application timings, as predicted by weather models, are currently not quite right. A slow spring is now occurring. Last week’s forecast of heavy rainfall over a large region in the United States was realized, and this time Illinois largely dodged Mother Nature’s deluge. Worst hit by extreme flooding was reported in Arkansas, Kentucky, Georgia, Indiana, Missouri and Tennessee. The Masters golf tournament was also impacted, but only on Monday’s practice round. The weather forecast is now good for uninterrupted play.
What kinds of things are we looking for/scouting for right now? Well, we are especially interested in plant phenology or the early development of plants in the spring. In spring plant phenology is a good way to double check degree day models and in 2025 it would be prudent to use both (think of it as crossing your t’s and dotting your i’s). This Scouting Report will detail two of our newest pests as both occur in early spring. 1) A new fungal disease discovered in Chicago last April which is currently called “yellow patch” and can negative effects to annual bluegrass greens. Researchers in the Mid-Atlantic (UConn) are working to identifying it/ and find solutions. 2) A second is annual bluegrass weevil (ABW) an insect who’s larvae/grubs feed on Poa annua roots. It was first identified in Chicago in August, 2023.
Finally, the beginning of each golf season is a good time to spotlight articles which appear in the Chicago District Golfer magazine. We have had a monthly turf column since 2022 where the CDGA green committee members write from a golfer’s perspective. Their efforts are helping to explain the complexity of turf maintenance and more. Enjoy!
Weather
Scouting for 2 New Issues — Annual Bluegrass Weevil (2023 1st report) and Yellow Ring (2024 1st report)
Scouting for Disease — A new Basidiomycete Disease Causing Yellow Rings (Waitea Patch look-a-like)
A newer fungal disease causing yellow rings/patches on a annual bluegrass/creeping bentgrass greens was first identified at a golf course in Chicago during April, 2024. Within about a month, two more cases were identified. In each, yellow ring symptoms were associated with Poa annua greens. The Chicago metro golf course locations represented were located in north, south and west suburbs.
Dr. John Inguagiato, @UConnTurfpath
On social media, Dr. John Inguagiato shared a newer disease causing yellow rings in Connecticut. This then helped us identify it in Chicago. It’s easy to misdiagnose because the symptoms of bright yellow rings on Poa annua putting greens are very similar to Waitea patch.
- Time of year — cool and wet during mid-April (2" soil temp of 55 degrees)
- Type of greens— push up construction having a large proportion of Poa annua versus creeping bentgrass
- Symptoms— yellow rings which can be misdiagnosed as Waitea Patch
- Fungal characteristics — After incubation, clamp connections were easy to see using a compound microscope and sometimes twisted together like a rope.
- Fairy ring — Basidiomycete fungi are associated with fairy ring symptoms and all have clamp connections associated with mycelium septations.
Recommendations
Stick with your fungicide program for 2025. Yellow patch symptoms match up nicely with the standard first preventive fairy ring application timing which uses 55 degree soil temperature at 2" depth. If you suspect yellow rings get a diagnosis from a university lab.
- Maxtima by BASF has been tested for this new disease and works well personal communication with John Inguagiato
- Avoid older DMI fungicides as they tend to have more growth regulation; You may unintentionally halt needed turfgrass growth and recovery in the early spring
- Hand water dry areas of affected greens to avoid midday wilt stress — do not want yellow rings progressing to brown rings
- Consider a wetting agent application if history of LDS is known and/or if spring weather conditions are overly dry
Most Recent Information on Yellow Ring, Mar 28, 2025
Scouting for Insects— Annual Bluegrass Weevil, Listronotus maculicollis
This insect is commonly referred to as ABW. It is only a problem in turfgrass maintained at low mowing heights (0.5 inch or less). This means it is a unique to golf courses: Fairways, tees, green collars and green surrounds are vulnerable to damage. Higher heights of cut (roughs or home lawns) are not impacted.
Found in Illinois
Previously the annual bluegrass weevil did not exist in Illinois. This week a Chicago golf course with annual bluegrass was found to have annual bluegrass weevil larvae and adults. In this case only a portion of a collar of a few greens were negatively impacted. The actual green surface was not affected — required daily mowing (and clipping removal) protects greens from ABW establishment and damage.
History
The annual bluegrass weevil was originally detected in Long Island, New York in 1957. It’s early spread (1957–1970s) was closely tracked and ABW was thereafter found in the states of New York, Massachusetts, Rhode Island and Pennsylvania. Today, it continues to spread slowly and has now been identified in several more states as well as territories in Canada. Primary mode of introduction is the transport of infested sod containing ABW.
Quick Points
- Application Timings for ABW. Timing is important and has been attained using growing degree day (GDD) models. For example, first insecticide application is in the spring when overwintering adults become active (~April in Chicago).
- Plant Phenology Timing for ABW. In the spring can also use plant development indicators. First spring application for ABW would coincide with Boarder Forsythia bloom when it is 1/2 yellow (just past peak bloom) and 1/2 green (as it begins to leaf out).
- Root Loss. Turf damage is caused by root loss via active feeding of the insect larvae (grubs). Adult feeding is not important.
- Newer Insecticides. Newer options exist and their use lessens risk of insecticide resistance by ABW. Rotation of different chemical classes of insecticides is key in the management of ABW.
Most Recent Information on Annual Bluegrass Weevil in Chicago, Apr 4, 2025
Slow start to spring: Monitoring ABW activity amid cool conditions in Chicago
CDGA Turfgrass Program Library
Weekly Scouting Reports
Produced weekly by Dr. Derek Settle and Shehbaz Singh during the golf season, the CDGA Turfgrass Scouting Report features industry-specific content on the preceding week’s turf conditions. Content includes pictures, weather data and research to illustrate what is currently happening and/or what is predicted to happen in the Midwest. Click here for full list of Scouting Reports.
Magazine Articles
In select issues of Chicago District Golfer magazine, CDGA Green Committee members write pieces on turfgrass topics that impact every golfer. Reading these articles will give golfers a better understanding of the challenges faced by superintendents and grounds crews. Articles include best practices on the golf course, recent environmental impacts and more. Click here for full list of Magazine Articles.
Peer-Reviewed Research
The CDGA Turfgrass Program conducts numerous research projects to provide up-to-date solutions to member organizations. Research projects includes turfgrass disease management, turfgrass weed control, turfgrass variety evaluations, and much more.
Educational Videos
Numerous educational opportunities exist for CDGA member clubs. Online education includes the use of weekly scouting reports, research reports, social media and other digital platforms such as video.
Final Photo
Newer varieties of both warm season turfgrass species have improved tolerance to cold temperatures. We thank Dr. Yanqi Wu, Oklahoma State University and Dr. Jack Fry, Kansas State University for providing some of the most recent turfgrass varieties of bermudagrass and zoysiagrass for testing in the Chicago-area.
