Grubs and grub control are nothing new for golf course managers. For as long as there have been products available, superintendents have made preventative and curative applications to control white grubs in turf. If left unchecked, white grubs can kill large sections of grass in short order. When fall arrives, superintendents aren’t the only ones on the lookout for white grubs. Animals like racoons, skunks and even turkeys are searching for their next meal and it is common to find grass rolled up in the rough like sod. While this is not ideal, it does give superintendents a chance to map these areas so they know which hot spots to treat preventatively next year.
When white grubs are observed or expected based on historical data, applying appropriate insecticides will control the population and limit direct and indirect damage. Preventative treatments containing imidacloprid, chlorantraniliprole or thiamethoxam are most effective when applied in late spring to early summer. Exact timing will vary by region so do your homework on the best time to apply. Since we are well past prevention, curative applications are needed if you are seeing grubs now. Insecticides containing trichlorfon or carbaryl are the only two options for rescue treatments.
On top of that, you also need to deal with small mammals, birds and other wildlife feeding on the grubs. The use of repellents and deterrents can help keep them away or in some cases they can be trapped for relocation. Continue to trap or apply deterrents even after a curative application is made because the pests will keep coming back to the same areas in search of grubs.
Lastly, proper watering and fertilizing is important after grub damage to regrow roots and ward off desiccating winds. Because white grubs feed on roots and then animals roll the grass up, you should treat recovery as a grow-in. Repairing grass that’s been torn up is just like placing sod in the rough. Without frequent water and fertility, roots will dry up and the grass will die. For more tips on insect control or any other issues at your course this fall, please reach out to your regional USGA agronomist.
Northeast Region Agronomists:
Darin Bevard, senior director, Championship Agronomy – dbevard@usga.org
Elliott L. Dowling, regional director, East Region – edowling@usga.org
Brian Gietka, agronomist – bgietka@usga.org
Information on the USGA’s Course Consulting Service
Contact the Green Section Staff