Selection and Timing of Grub Control Products for Homeowners

Dr. David Smitley and Terry Davis
MSU Dept. of Entomology

If you are one of those lucky people that found part of your lawn was dug-up and turned-over by skunks or raccoons last fall or this spring, then you may want to consider applying one of the ‘Best Choices’ listed below, to protect your lawn from grubs this year (next fall and spring).  If you had a raccoon party in your yard, then it is almost certain your lawn was heavily infested with C-shaped white grubs, the larval stage of Japanese beetle, European chafer, or June beetle, which eat turf roots.  If there are enough grubs they will consume most of the turf roots, making it easy for skunks to turn-over patches of turf.  Lawns that are mowed at the highest setting on your mower, receive a modest amount of fertilizer, and are watered during dry periods produce a dense mat of roots that is tolerant of grubs, and difficult for raccoons to dig.   However, if your lawn was thin and heavily infested with grubs last fall or this spring, you may want to use one of the products below sometime in the next month, to protect your lawn from grubs so you can start building a healthy lawn again.  For all of these products, apply irrigation (irrigation system or lawn sprinkler) immediately after application to soak the insecticide into the root system where the grubs will be.  The biggest cause of failure, is failing to water after application.  In late April, Terry Davis checked 4 garden centers in the mid-Michigan area to see what products they sold for grubs.  Here is a list of the products he found, and when they should be applied:

Damage from raccoons digging for grubs.

Best Choices for Grub Control Products

1. Scotts Grub-Ex - Granular
   chlorantraniliprole 0.08%
   Apply between April 15 and May 15 for best results, but can be applied through June 20^th.
2. Bayer Advanced Season Long Grub Control and Turf Revitalizer - Granular
   imidacloprid 0.25% and fertilizer
   Apply between June 1 and July 15 for best results.
3. Bayer Advanced Complete Insect Killer Granules - Granular
   cyfluthrin 0.05% and imidacloprid 0.15%
   Apply between June 1 and July 15 for best results.
4. Bayer Advanced Season-Long Grub Control Liquid - attach-to-hose-bottle
   imidacloprid 1.47%
   Apply between June 1 and July 15 for best results.
5. (local distributors name) Premium Grub Control (Do not confuse with "Premium Insect Control")
   imidacloprid 0.2%
   Apply between June 1 and July 15 for best results.

Poor Choices for Grub Control Products

8. Bayer Advanced Complete Insect Killer Liquid attach-to-hose-bottle
   cyfluthrin 0.36% and imidacloprid 0.72%
   This product will not deliver enough imidacloprid to work effectively - do not confuse this with the Bayer Advanced combination granular or the Bayer Advanced attach-to-hose-bottle product containing only imidacloprid (both of which do deliver enough chemical per area to be effective).
9. Spectracide Triazicide Insect Killer Once and Done Granules
   gamma-cyhalothrin 0.05%
   Will not kill grubs at any rate.