- In June or July, the beetle lays its eggs just under the ground surface. About two weeks later, the eggs hatch into grub larvae. The C-shaped white grubs start feeding on the grass roots. As the grub grows to about 1/4 to 1 inch, it continues to feed on the roots. During fall, when the soil temperatures cool, the grub moves down about 8 inches into the ground for the winter. In spring, the grubs come back to within 3 inches of the ground surface. At this time, the grub turns to the pupa state, which then emerges from the ground as a beetle to fly around and lay more eggs, after which time, the beetle dies.
- The holes in the lawn are caused by moles, skunks and raccoons digging 3 inches into the soil to feed on the grubs. Wherever there are grubs, you will see these holes, which are about the size of a nickel or a quarter in diameter. Not only will you have brown patches of dead grass from the grubs' feeding, but you also will have holes in the yard.
- In areas where there are brown patches of grass or holes, cut the sod 3 inches deep and pull back a 1-by-1-square-foot section. If you see five to 10 grubs, you need to treat the patches or, if you have more dead grass than growing grass, the entire yard.
- Use milky spore disease to kill the grubs during late summer or early fall, when the grubs are actively eating. Milky spore is a bacteria that the grubs will eat. After the bacteria enters the grub, it slowly kills it. After the grub dies, it disintegrates and releases millions of bacteria into the soil for continuing treatment to kill more grubs and any new grub larvae that may appear. Eventually, you will have a grub-free lawn.
previous post