White Grubs, or simply “Grubs”, are the larvae form of different types of beetles like the European chafer, the Japanese beetle and the June bug (beetle). These grubs live to eat the roots of your grass and can cause serious damage to your lawn in a short amount of time. Even well fertilized and watered lawns can fall victim to severe grub damage. Often times once a grub problem is realized, damage to your lawn has already occurred. Protect your lawn against damaging grubs by scheduling a yearly grub control today.
The Grub Lifecycle
Understanding the lifecycle of lawn grubs is essential to controlling them. The illustration below shows the lifecycle of grubs in Michigan. Grubs are most active during the peak growing months of April, May, August, September, and October when they spend their days devouring the precious root system your lawn needs to absorb water and nutrients.
grub-lifecycle-modern-lawn-careAs your lawn begins growing in the spring time, grubs start eating the roots of your lawn until late May when they enter the pupae stage. The pupae stage is in-between the larvae stage and the beetle stage where they are resistant to insecticides. In June, the pupae’s turn into beetles and emerge from the ground to feed on the foliage of plants and trees in your landscapes. At this time the beetles start mating and proceed to lay eggs which generally hatch by early August. These newly hatched grubs once again start feeding on your lawns roots until cold temperature force them deeper into the ground by mid-November.
controlling-grubs-modern-lawn-careAfter learning the lifecycle of a grub, we can see that grubs hatch in early August. This is the stage where grubs are most easily controlled. Using this information, we apply grub control in the months of June and July. This allows ample time for grub control products to get watered into the soil before the eggs hatch. When the eggs do hatch, the young grub larvae absorb the grub control product which causes them to lose their appetite. At this point the grubs stop eating and die off before any damage occurs.
Most grub control products are designed to be used during a specific period of time. The most common grub controls aim to kill grubs within a few days of the application. These products are target actively feeding grubs in the spring and fall. The window for spring treatment is very small. From the point in time when grub damage surfaces until the grubs enter the pupae stage can be only a week or two depending on the season. This short window is very easy to miss. Also applying these types of products during the summer months does nothing since there are no grubs in the ground until August. Coincidently, applying preventative type grub controls while grubs are actively feeding will yield zero results.
Where Did I Get Grubs From?
Since grubs are the larvae of beetles, they can easily be easily spread to your lawn. Once hatched, beetles take off in search of feeding and mating grounds, sometimes traveling long distances. With this in mind you can see how grubs can easily take up residence in your lawn. Certain types of trees and shrubs can attract beetles to your property. Having beetle prone trees and shrubs in your property significantly increases your chances of developing a grub problem in your lawn. Sometimes you will notice the area under or near a tree or shrub appears to be dying. This is usually due to grubs. The beetles feed and mate in the trees or shrubs and lay their eggs close nearby. If your property has any of the following trees or plants, it will be at a higher risk for a grub problem.
A grub control application can also benefit your trees and shurbs; by getting rid of grubs in your lawn, you can significantly reduce the number of beetles that can feast on your trees and shrubs the following season.
Symptoms of Grub Damage:
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Symptoms of Grub Damage
As your lawn starts to green-up in the spring. Check out your lawn for spots that never green up. Take hold of these non-green spots and pull. If the turf peels up easily, and/or there are grubs present, you have a grub problem.
If your turf is well irrigated during the late summer or early fall and you have irregular brown patches not due to drought, you may have a grub problem. Use the peel back technique mentioned above to check for grubs.
If your lawn is torn up from animals digging at it, you may have a grub problem. Many animals and birds eat grubs and will destroy your lawn to get to them. These animals also eat earthworms though, so use the peel back technique to confirm grub presence before scheduling an application.
If you notice heavy populations of June or Japanese Beetles, you will likely have damaging grub population the following fall and spring.