17 Jul Grub Worm Control
Grub Worm Control
Have you noticed little white grubs in your lawn? White grub worms are a huge nuisance in many homeowner lawns found throughout the United States. This week, Sod University takes a deeper look at the grub worm. Once you learn more about the grub worm and are able to accurately identify a grub worm infestation, you can then begin strategizing ways to get rid of them and prevent future infestations. Check out some of our recommended insecticide products for treatments and read the article below for more information.
Coverage: One bottle covers 2,500 sq. ft.
Active Ingredient: Gamma-Cyhalothrin 0.08%.
Ease of Use: Easy to use and attaches to the end of your garden hose.
Best Used On/For: Outdoor general insect control.
Merit 2F Liquid
Application Rate: 14–17 mL. per 1,000 sq. ft.
Active Ingredient: Imidacloprid 21.4%.
Ease of Use: Requires tank mixing and spray application.
Best Used On/For: Liquid broad-spectrum systemic formulation used for outdoor insect control.
Imidacloprid .5 G Granular
Application Rate: 1.2–1.8 lbs. per 1,000 sq. ft.
Active Ingredient: Imidacloprid 0.5%.
Ease of Use: Granular formulation that is easy to apply with a spreader.
Best Used On/For: Broad-spectrum systemic formulation that offers preventive and curative treatment of insect control in turfgrass and landscape ornamentals.
What is a grub worm?
First off, it is important to know that grub worms, the larvae form of billbugs and scarab beetles, can be found in lawns and gardens of North America—especially in Florida’s humid temperate conditions. Since Florida doesn’t endure harsh winters, grub worms can thrive and multiply all year long. Grub worms, also called masked chafers, can be found in the soil and damaging lawns by feeding on grass roots. Grub worms range from a quarter inch to two inches in length, and are easy to identify with their cream-colored bodies. They have six legs and a dark-tinted abdomen due to soil particles showing through their exoskeleton. At the adult stage, grub worms turn into beetles that emerge from the soil. You may begin to notice grub damage as they eat the leaves of your grass and other plants in your garden.
Signs of Infestation
Although grub worms can be found in some cool season grasses like fescues, ryes, and bluegrasses, they like to infest warm season grasses such as zoysia, Bermudagrass, St. Augustine, and buffalograss. A common sign of infestation is the increased presence of digging or burrowing pests—for example, moles. Burrowing mammals are likely after the source of grub worms within the soil. Another sign of infestation may be the appearance of weeds. As grub worms feed on the root system in your lawn or garden, it becomes weaker and makes it hard for your garden or lawn to outcompete weeds with. Lastly, dying or a damaged area of grass may be caused by grub worms. Since the root system and plant bed has become weaker, grass may feel spongy or easy to lift up like a piece of carpet.
The absolute best way to identify a grub worm problem is to actually see a fair amount of grub worms in your soil. Examine several soil selections throughout your lawn and garden sized three to four inches in length and four inches in depth. If you find more than five grub worm per square foot, treatment is imperative.
Treatment & Prevention
Once you have detected and identified grub worm activity, a treatment and prevention strategy is necessary. The best time for grub treatment is in the late summer or early fall, as they are still small and near the soil surface during their lifespan. They are less vulnerable to treatment in the spring since they are larger and no longer feeding as much. See the image below for more details. As mentioned at the top of this article, there are several insecticides that are known for treating white grub worm infestations including Spectracide Triazicide, Merit 2F Liquid Insecticide, and Imidacloprid .5G Granular Insecticide.
Image from https://www.wrightsfeeds.ca/grub-damage/
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