GRUBS

”White grubs are beetle larvae, and can be found in the root zone of damaged grass. Grass chewed on by grubs often looks like it has not been watered, typically turning brown in patches. A telltale sign that grubs are feeding is that damaged grass can be lifted or rolled up like harvesting sod (or a toupee!)...We have two kinds of white grubs in Wisconsin, May/June beetle and Japanese beetle; your grubs could be either or both. They are creamy white with tannish/brown heads and bottoms, and curl up into a circle about the size of a quarter. The critters who find them so tasty include raccoon, mole and the ever popular skunk. These animals actually do more damage to the lawn than the grubs, but if you can get rid of the grubs you will get rid of the digging as well”

Two windows to proactively treat for grubs

PROACTIVE EARLY SPRING

Treating in March-April is a proactive approach to to kill the mature grubs coming out of Winter dormancy, in the early spring when they are closest to the top of the soil. There is a short window for application in early spring before the grubs get too big and pupate. Grubs burrow deep into the soil and rest through the winter. Some move as much as 12 inches below the surface. With the Spring warming, the soil temperatures rise and the grubs, if present, will migrate to the top of the soil and will begin feeding on the grass roots.

Easier to kill the juvenile grubs in the Fall than the mature grubs in the Spring hatching from the beetle’s eggs, as that is when the smaller, young grubs are most susceptible to nematodes.

The grub control product is granular Acelepryn on a primary limestone filler carrier, 0-0-7, so 7% potassium. 

The best time to kill  grubs when they are closest to the top of the soil. In the late summer to fall, the grubs are just barely starting to grow and they are much closer to the soil surface so they are easier to kill.   

A grub’s life cycle begins in the summer when adult Japanese beetles lay eggs underneath the soil. They feed on grass roots through the fall and then dig down and go dormant during the winter. 

More information is available on the life cycle of grubs - just ask!