Planning White Grub Control in 2023

White grubs are still months off in many parts of the country, but now is the time to start planning your application(s). Here’s some tips.

Choose the right product:

• Tetrino^® - The latest broad-spectrum insecticide from Envu is guaranteed to control all white grub species and has performed exceptionally well the last two years
  • Tetrino protects systemically for 100 days plus or season-long control
  • Tetrino is highly versatile, providing excellent control of annual bluegrass weevil, caterpillars, billbugs, and chinch bugs
  • Tetrino acts quickly on grubs and other insects shortly after application, unlike other diamide insecticides
  • For season long-grub control, apply 32 fl oz/A as a single application between late June and early August
  • For added flexibility with multiple insects, Tetrino can be applied as a split application with 16-32 fl oz/A applied in the spring for early-season pests (billbugs, cutworms, ABW etc.) and 16-32 fl oz/A applied again in July/August for white grubs 

• Still using Merit^®? Merit has been the industry standard for a long time and it is critical to use the maximum label rate of imidacloprid (0.4 lbs ai/A per year). Be careful with some combination Merit/fertilizer products because their high label rate equates to less than 0.4 lbs ai/A. Here are the recommended rates:
  • Merit 75WSP = 5 x 1.6 oz packet/A per year
  • Merit 0.5 G = 80 lbs/A per year
  • Merit 2F = 1.6 pt/A per year
  • 0.2% Merit on Fert = 200 lbs/A per year
  • 0.15% Merit on Fert = 266 lbs/A per year

• Timing is everything – As an industry, white grub applications have moved too early in the summer which doesn’t make sense as most damage is done by racoons, skunks, birds, etc. early in the fall. Start applications when you see the first adult beetles (usually late-June or early-July)
• How late is too late? – applications well into July and even early August are highly effective with Tetrino and Merit^. Though both products have long soil residual, later application dates insure protection into the fall when animal feeding can be damaging.
• Water it in - Irrigation or rainfall should ideally occur within 24 hours after application of Tetrino (0.1-0.25”) and Merit (0.25-0.5”) to move the active ingredient through the thatch into the soil profile
• Minimize thatch - Thatch layers > 0.5 inch can severely limit insecticide movement to the area of grub feeding
• Grub control struggles? – The above 5 bullets should help but here are some additional pointers:
  • Research shows even the older products like Merit still perform as well as in the past
  • University researchers continue to report no issues with resistance to white grub insecticides
  • Consider installing light traps to confirm the species and peak flights on your particular property
  • Consider multiple applications to extend the insecticide efficacy if a history of late breakthrough is common

• Need more info? – Be sure to read and follow all labels and contact your Envu area sales manager if you need assistance 

White grub controls should be applied once adults are seen in the landscape to ensure control through the fall and preventing vertebrate feeding (Envu).