It’s Time To Treat For Grubs!

Lawn with trees

Did your lawn suffer damage from grub activity or small animals such as skunk’s, raccoon’s or armadillo’s? If so, these small animals dug up your lawn to snack on grubs…

Grub 101

  • Grubs are the larval stage of scarab beetles. 
  • There are at least 10 species of grubs that are pests of home lawns. They are considered the most destructive of all lawn inhabiting insects.
  • Of the native species, the Northern and Southern Masked Chafers, May beetles, and green June beetles are the most widespread.
  • There are four accidentally introduced species:
    • Japanese beetle – the Japanese beetle is the number one insect pest as it can damage plants and lawns during two life stages.
    • Oriental beetle
    • European Chafer
    • Asiatic Garden – the Asiatic Garden beetle has regional significance, mostly in the Northeast US.
  • The adults feed on over 300 plants including roses, linden trees, garden beans, grapes and even poison ivy.
  • The larvae feed on the roots of all cool-season turfgrasses, causing significant damage to lawns.
  • The type of damage that the adult Japanese beetles inflict on the leaves is called skeletonizing as they feed on the tissue between the leaf veins.
  • If populations are high enough, they have the ability to defoliate a tree in a few days. The tree will not die as a result of this attack and generally the tree will regrow enough leaves to survive.
  • The adults of the Asiatic garden beetle, green June beetle, and May beetles also feed on an assortment of plant materials, but usually not to the same extent as Japanese beetles.
  • The European Chafer and North and South Masked Chafer adults do not feed on any plant material during their life stage. The adults may not feed, but the grubs, especially of the two Masked Chafer species, can do significant damage to a lawn.

Damage Control

There are several options for controlling grubs before they damage your lawn. If you choose the chemical option or try one of the biological controls, be sure to read and follow all label directions.

Many of these products need to be watered within a short period of time after the application to be effective. Grub control products from hardware or home improvement centers work best when applied prior to the grubs laying their eggs. The material needs to already be in place when the larva hatch to provide effective control. You can also contact a local Spring-Green office to schedule this service for your lawn. Applying a grub control is good insurance against these lawn damaging insects.

Have You Started Seeing Grubs In Your Lawn This Year?

grubs

I recently received a call from a Spring-Green Franchise Owner about dealing with grubs in the spring. He had received a call from a customer who stated that they had grubs feeding on their lawn.  This confused the Franchise Owner and the customer as they both thought that grubs were only active during late summer and fall of the year.

The typical annual white grub female lays her eggs in late spring through mid-summer.  These eggs hatch in late summer/early fall as c-shaped grubs and begin feeding on turf roots, soil, and other organic material that they come into contact while foraging for food.  They will feed throughout the fall and even into early winter depending on the soil temperatures.

As it becomes colder, grubs will burrow down into the soil to escape the frost line.  During the Polar Vortex of 2014, these grubs were found to have dug as deep as 36 inches to stay below the frost line.

In the spring, when soil temperatures begin to warm, grubs will begin rising to the surface, feed a little bit, than burrow back into the soil where they make a small capsule in the soil to pupate and emerge as adults in late spring to early summer. Then the whole process begins again.

Unless the spring is very dry, most people don’t even notice spring grub activity. They don’t feed as voraciously in the spring as they do in the fall. They will still feed on turfgrass roots, but usually the grass is growing quickly and the roots are replaced before any damage is noticed.

Most people will discover grubs in their lawns in the spring when they may add or expand a landscape bed. When the turf is removed, the grubs are easily seen. If left alone, they will dig themselves back into the soil. If there are not too many of them, they can be collected, placed in a bag and disposed of in the garbage.

The other time that homeowners will find grubs is when a skunk, raccoon or opossum start digging up the lawn looking for food. These critters do more damage to a lawn than the actual grubs as they tear it up.

Applying an insect control in the spring is usually not recommended as the grubs are not feeding enough to ingest enough of the control material to kill them. The best thing to do is to make sure you apply a grub preventative in early summer. This material will prevent the eggs from hatching or growing, and then grubs will not be a problem in your lawn.

Contact your local Spring-Green office to inquire about our grub preventative service and how they might be a good fit for your lawn.

Is It Going To Be a Good Year for Grubs?

service_grub-control

I guess the answer to this question depends on your perspective. If you are a homeowner, you hope that it is not a good year for grubs. If you are in the lawn service industry, you want the preventative products you applied earlier in the summer to have worked so the lawns you treated are protected, but you don’t mind the extra revenue that comes from selling grub control treatments, so you are hoping for a good year for grubs. From the grubs’ perspective, I guess they are hoping that it is a good year.

I often check with our franchisees in the areas where grubs are a problem to find out what they are seeing. Our franchisee in Oak Creek, WI, Phil Bowen is seeing active grubs in a couple of his lawns. We are also getting some isolated reports of active grubs in suburbs of Chicago. We have a couple offices in central Iowa and they are experiencing a major drought this year, so they have not seen any grub activity so far. The Mid-Atlantic states may have grubs, but they have had so much rain this year that any grub activity may be masked since the grass is growing well, recovering from any feeding. Damage could be seen if it turns dry for a couple of weeks.

The amount of rain an area receives has a direct effect on grub populations. It is possible that parts of the Midwest that went through a drought last year may have less activity this year as the populations of grubs were down last year. This is because female grubs rely on soil moisture to keep their eggs moist and viable.

Adult female grubs dig a small hole into turf and lay their eggs. If the soil is too dry, the eggs will dry out and die. If this happens over a large area, such as what was experienced last year in parts of the Midwest, the overall populations can be reduced. Granted, there are still many lawns that are irrigated, so plenty of grubs still made it, but overall, the populations can be reduced by drought.

We will just have to wait and see if it will be a “good” or “bad” year for grubs. The cooler spring and early summer may have pushed back the adult emergence, which in turn, may affect when the eggs hatch. Keep an eye out for areas of turf that appear to be turning brown when the rest of the lawn looks good. Do the “tug test” to see if the grass pulls up like a carpet. If so, you may have grubs.