What are the keys to controlling Turf Grubs?
To start, identify that you have a problem. The larvae of Beetles (Turf Grubs) are typically ½ – 1 ¼ inch, worm-like, C-shaped insect pests that spend the majority of their life underground. They look somewhat like shrimp living in the soil.
Despite being small, when left untreated they can cause some BIG, expensive problems:
- Killing your grass by feeding on the roots.
- Encourage secondary foragers such as crows, skunks, and raccoons to dig up your turf as they search for and feed on the tasty morsels.
- By mid-summer, the grubs will turn into voracious foliar and flower-feeding beetles that can destroy ornamental plants, trees, and fruit & vegetable gardens, which in some cases is more destructive to your yard than the grubs.
The Signs You have a Grub Problem
During the spring when ground and air temperatures start to warm up, grubs that retreated deep into the soil during the cold winter will move up near the surface of lawns to feed on the roots.
Areas of your turf that look dead or thinning among an otherwise healthy lawn may be a sign of grub damage. If you had turf damage from an infestation of adult beetles the prior year then you likely have a grub problem this spring.
To confirm the presence of grubs, use a shovel to peel up a section of unhealthy or browning lawn to identify whether grubs are present 1-2 inches below the surface. Typically, 5-10 grubs per square foot is enough to cause noticeable damage.
Preventative Maintenance
A well-thought-out preventative maintenance plan can save you both time and money down the road. Proper watering and fertilizer treatments at regular intervals are keys to your turf’s health. Healthy turf will be able to withstand (or mask) a grub infestation better than turf that has not been maintained.
Part of your springtime preventative maintenance should include an application of grub control treatment to keep any suspected grub populations under control.
Springtime treatments can also help reduce populations of destructive beetles during mid-summer: it will be easier for you to control these pests while they are localized and relatively stationary in the turf before they turn into adults and take flight.
Beetle Infestations…
Damage from Japanese Beetles in the United States amounts to millions of dollars in losses per year with most damage occurring in the Midwest and East Coast. However, the problem is no longer isolated to the eastern half of the country.
Japanese beetles continue to move westward and south and now have become a big nuisance in Colorado, and even in isolated areas in California, Washington, and Oregon.
The beetles are adult stages of the grub larva that emerge from the ground during the summer months. Once the beetles emerge from the ground they will feed on a wide variety of fruits, vegetables, ornamental plants, and trees.
Lead to the Beginning of the Grub Life Cycle
Within 2 weeks of peak flight, adult beetles begin to lay their eggs. Soon, grubs will hatch and begin the cycle all over again.
Most professional lawn care operators find that this is the best time to treat for grubs; when they are in their early stages of development and most susceptible to grub control treatments. Typically, this is during mid-summer; July to early August.
Secondary Foraging for Grubs
Most homeowners don’t even realize they have a grub problem until their well-manicured yard is visited by pigs, skunks, raccoons, or crows that dig up yards in search of fattened-up grubs that continue to grow into the fall.
Unfortunately, secondary foraging usually causes A LOT more damage than the grubs do. It’s not uncommon for these animals to destroy entire yards! Traditionally, harsh chemical products were the best products to use in the fall against these larger, more mature grubs.
But Japanese Beetles Don’t Inhabit My Area
It is true that these colorful creatures of iridescent green and red, capture the most headlines but Japanese Beetles are just one species in the Scarab Family that is present across North America that causes damage to lawns and gardens.
Other damaging Scarab Beetle grubs and adults, weevils, and borers include:
Asiatic Garden Beetle, European Chafer, Rose Chafer, May or June Beetle, Northern Masked Chafer, Southern Masked Chafer, Black Turfgrass Ataenius, Green June Beetle, Oriental Beetle, Leaf Beetles such as Rice and Alder Leaf, Weevils such as Annual Bluegrass, Sweet Potato, Pepper, Pecan, Citrus / Strawberry Root and other Root Weevils, Flea Beetle, Borers such as Emerald Ash Borer, Gold Spotted Oak Borer and Soap Berry Borer, and Darkling Beetles.
Benefits of Integrated Pest Management (IPM) Programs
Integrated Pest Management (IPM) is an approach to pest management where we rely on a combination of practices, including using a proven chemical product at a low rate in combination with a powerful non-chemical, biological product. Usually, the active ingredient in chemical grub control products is either imidacloprid or acelepryn. Both are effective at grub control, but when used in combination with a non-chemical, biological product such as grubGONE! the effects are even better.
Research conducted at NCSU shows that grubGONE! used alone controls 80-90% against Scarab Grubs. When grubGONE!’s naturally occurring BTG is used in conjunction with a low rate of a product containing imidacloprid, the results improve to nearly 100% Scarab Grub control. This would be an effective regimen for anyone looking to reduce chemical loads while still achieving very high results during times of high infestations. In addition, a successful IPM process includes proper maintenance, watering, and feedings to ensure your turf is healthy.
Are Beetle Traps Worth It?
Similarly, IPM programs can be used to combat Japanese Beetles. Beetle traps have mixed results – they trap lots of beetles, but attract many from surrounding areas. So, by using them near your garden you may actually be doing more harm than good. During unusually high Japanese Beetle infestations, it may be good practice to place traps far away from your gardens in an effort to lure some beetles away from your plants. Then you can control the lower populations of beetles on your plants organically with products like BeetleGONE! tlc.
Written by NGB member: Phyllom BioProducts
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4 Comments. Leave new
Do those chemicals kill ground nesting bees and wasps? How do they affect other wildlife such as butterflies and moths, frogs, toads, lizards and others that use the ground to shelter in during the winter?
Here is what is said about pollinators on their website “Highly effective at controlling grubs & beetle invaders and are safe for kids, pets, honeybees, birds & wildlife. The active ingredient, our patented strain of Bt, is used in organic farming – so feel free to use it in your fruit and veggie garden too!” It is good to use around wildlife. Learn more at https://beetlegone.com/
Grub gone is not available in California. Any other suggestions? Do other BT products work?
Yes, Both products – beetleGONE! and grubGONE! are registered and available in California through online sources. More information can be found at https://beetlegone.com/products/grub-gone