Knowing the damage grub worms can cause to a lawn will give you a different perspective on the importance of grub worm prevention. In order to understand how to prevent lawn damage from grubs, let’s take a look a their life cycle.
While all beetle larva are considered grub worms, the Japanese Beetle in particular is the beetle that we see causing most of the damage to lawns in Indiana. In this article, we’re focusing on the Japanese Beetle and prevention of its larva.
Life Cycle of the Japanese Beetle
Japanese Beetle larva are typically first seen emerging from the ground in June in north central Indiana. Adult Japanese Beetles have two purposes in life: feeding (usually on ornamental trees and shrubs, creating skeletonized leaves) and producing offspring. Their adult lives are short, but they can cause plenty of damage to your landscape.
When people worry about Japanese Beetle damage, you’re probably thinking mostly of this damage to shrubbery by adult beetles, without giving much consideration to the larva. However, you should also consider their eggs as they lay them in your lawn.
In early summer, the larva pupate and emerge as adults to begin feeding. By mid-summer, they begin laying eggs in the turf. The eggs hatch soon after, and the new larvae begin feeding on the roots of your grass; you will begin to see damage they have caused to your lawn anytime between August and November. As the temperatures drop, the now-large larvae will migrate down into the soil to spend the winter; when temperatures rise, they will migrate back up into the root system to feed again in spring. The cycle continues as the grubs pupate into adults. (See the attached chart of life cycle of a typical annual white grub.)
Grub Worm Prevention
If you wait until you see damage in your lawn to treat for grub worms, you are already too late; the damage is done to your root system. (I have even had clients whose lawns were fine when they went to bed only to wake up to large dead areas in the lawn the next morning!) While there are curative products that can be applied once grub worms are recognized in the lawn, at that point you are just trying to minimize the damage already done.
A better approach is to recognize and treat for grub worms before they cause damage to the lawn and shrubbery. There are 2 different products that are primarily used to prevent grub damage: Merit and Acelepryn. While both are effective, there are several reasons I have decided to use the latter in my lawn care program. Acelepryn is applied earlier in the season for a longer window of protection, plus it offers protection against surface feeding insects, while Merit does not. Another benefit is that it is safe for our pollinating friends!
Get a handle on grub worms in your lawn before they do damage! Call Get Green Lawncare to make sure your lawn is protected this season.
Your lawn will thank you for it!