Grubs or white grubs, are the larvae of scarab beetles such as Japanese beetles, June beetles, or Rhinoceros beetles. They burrow into soil and eat organic matter such as roots. Bermuda grass and zoysia grass are common targets, as are garden and mulch beds, and vegetable gardens.
A few grubs are not typically an issue, and can be highly beneficial as they help breakdown organic matter, and are often used in compost piles. However, 5-10 grubs per square foot is considered an infestation, and can cause damage to garden beds and lawns. If you see patches of brown grass that are easy to pull out of the ground, this can be an indication that there is a grub infestation.
Grubs pose no harm to humans and are detritivores.
Grubs may attract birds, armadillos, and raccoons to your yard.
Grub and Beetle Lifecycle
Knowing the lifecycle is can help with the best times to treat for grubs.
Grubs have a lifecycle that begin as eggs which grow into larvae. These larvae may feed in soil for up to a year near the roots of plants and grasses. Once soil begins to cool, they stop feeding, dig deeper into soil, and become dormant during the winter. In Spring, they return to the root zone to begin feeding again. By late May, they return to deeper soil and transfor into pupae, and then emerge as an adult beetle weeks later.White Grubs – Lebanon Turf
Therefore, treating grubs in Summer and Fall are the best times when they are young and closer to the surface.
Natural Grub Prevention and Treatments
Simply relocating these grubs to another area is a simple way to get rid of them for one or a few grubs.
Grubs require moisture, therefore, reducing excessive water intake for your lawn and mulch beds can reduce the appeal for grubs.
A thick thatch can be attractive to grubs as a productive place to lay eggs. Dethatching removes this thatch.
During the summer, grubs live closer to the surface. Core aerating your lawn will most likely injure and kill grubs.
Use Milky Spore
Milky spore is a bacterial disease that that is eco-friendly and non-toxic option. This disease affects white grubs that become Japanese beetles. If you have May or June beetles, these option is not effective.
Nematodes are microscopic worms that can kill hundreds of different pests and insects, while being a non-toxic option that is harmless to humans and dogs. Since these are living creatures, they need to be purchased and used immediately.
Neem oil is another non-toxic option as a repellant and comes from seeds from the neem tree. It is non-toxic to birds, mammals, bees, and plants.National Pesticide Information Center