The 4 Best Lawn Beetle Killers

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Lawn beetle infestations are horrible. Many advertised insecticides do not work. They contain ineffective active ingredients. Do not be one of those people that figure that out too late. The solutions below will help you get rid of these beetles once and for all.

You probably found this page because you have an infestation. I hate lawn beetles. I bet you do too. And your lawn definitely does as well.

Lawn beetles are notoriously tough to get rid of because their life cycle in your soil is incredibly long. At any given time, you have beetles, mature grub, and young grub in your lawn. While one is feasting from above, the other is feasting from below.

Here are the best beetle killers that we recommend

The Best Lawn Beetle Killers

These are the different options for getting rid of lawn beetles. Most of them are preventative treatments (please read more before, it actually kills young grub), which is absolutely necessary to stop your beetle/grub problem. The last one is a curative problem, which means it will kill mature grub. Regardless, you will still need a preventative treatment. Please keep reading below to learn more about each one. 

Lawn beetle killers
Nasty grub infestation

Comparing Our Top 3 Recommendations for Lawn Beetle Killers

Best Lawn Beetle Killers

BioLogic Scanmask Beneficial Nematodes

BioLogic Scanmask delivers beneficial nematodes that naturally control pests like lawn beetles. Other than lawn beetles, it also kills fleas, fungus gnats, flea larvae, root knot nematodes, armyworms, western flower thrips, root maggots, cutworms, and black vine weevils. It is delivered in pack that contains microscopic nematodes. The nematodes seek out pest insects and enter their bodies. They eventually release a symbiotic bacteria that kills the pest. The best part is that it is completely safe for people, pets, plants, and beneficial insects.

BioLogic Scanmask is a very responsive company that is based in the USA. They only ship Monday-Wednesday to avoid transits over the weekend (to ensure healthy nematodes). They are also very responsive to customer feedback.

Tips: Make sure to refrigerate the nematodes as soon as possible upon arrival and until you use it. All you have to do is mix the nematodes with water and apply with a sprayer or BioLogic’s jet sprayer. Nematodes are pretty sturdy, but can be prone to die from the sun’s heat. So when distributing nematodes, it is best to do so in the evening hours and with plenty of water. Doing so will allow the nematodes to make their way into the soil before the afternoon sun the next day.

BUY HERE: BioLogic Scanmask Beneficial Nematodes

Scotts GrubEx Season Long Grub Killer

Scotts GrubEx Grub Killer uses Chlorantraniliprole as an active ingredient. This is a preventative insecticide. After application it will kill young grub for up to 4 months. Along with grub, it also kills caterpillar, chinchbug, larvae of cranefly and larvae of billbug.

Tip: It is recommended that you apply this with either a hand spreader or a push spreader (I personally recommend a broadcast spreader). As with the other insecticides, make sure to water after application so the maximum amount of insecticide can make its way into the soil. This will make it more effective.

BUY HERE: Scotts GrubEx Season Long Grub Killer

Bayer Advanced Complete Insect Killer for Soil and Turf Concentrate

Bayer Advanced Complete Insect Killer utilizes Imidacloprid as its active ingredient. This is a preventative insecticide. It will kill immature grub in their tracks. This bottle will make up to 80 gallons of spray. Along with grub, it will also kill ants, fleas, ticks, mole crickets, stink bugs, spiders, wasps, and cockroaches.

Tip: After application make sure to water your lawn so that the product can be absorbed into the ground. It is absorbed roughly 1 hour after application.

BUY HERE: Bayer Advanced Complete Insect Killer for Soil and Turf Concentrate

Andersons Duocide Lawn Insecticide Control

Duocide is a curative treatment for grubs (read more below). It will kill grub in all stages of their life cycle. In addition to grubs, it also kills fire ants, mole crickets, and fleas. The granules are easily spread and on contact to water Duocide’s granules disperse into thousands of microparticles which make their way into the soil easily.

Note that duocide contains carbaryl which is effective against grub. It also contains bifenthrin as an insecticide, but this is not effective against grub (but is effective against other insects).

BUY HERE: Andersons Duocide Lawn Insecticide Control

lawn beetle on leaf

Everything a Gardener Should Know About Lawn Beetles

It’s frustrating when you see a vibrant green lawn with small areas of thin or stunted growth.

The most common cause of thin lawn with patches are from stress from the previous summer or lack of fertilizer. However, if you see a bunch of birds feeding around these dead patches then you may have a grub problem on your hand.

Identify the Grub Problem

Before you freak out, first make sure you actually have an issue caused by grubs. Within your dead patch, use a shovel to dig up a few samples of turf around the bare spot. Dig to a depth of 2 inches. Look closely for small white, C-shaped grubs that are about 3/4 inch long.

Grubs may represent one of several different beetles. It may represent European chafers, Japanese beetles, or black beetles. Generally, these beetles lay their eggs in July-September. They tend to lay their eggs on lawns that well irrigated or even over-irrigated. Infestations are less likely to occur in lawns that dry out (not only surface level).

After the eggs hatch, the grub feed over the winter and after a couple of months, they are full grown (3/4 inch long). In the spring, they come out as full adult beetles. The grub will feed on the roots as the adult beetles may feed on the actual grass.

Look at the Active Ingredients

We highly recommend Scotts GrubEx Season Long Grub Killer, but if you choose to buy a product at a local lawn and garden store, be sure to read the active ingredients. Many products that say they control grubs don’t actually have effective active ingredients.

Water after Applying Insecticide

After applying the insecticide that you bought, you will want to water immediately. This allows better absorption of the insecticide into the soil. It also prevents the insecticide from being blown away by wind. This also makes the yard safer for children and pets to roam the lawn again.

2 Types of Approaches

There are two main types of approaches when you are trying to get rid of grubs and beetles:

  • Preventative – prevent future grub problems by killing younger grubs
  • Curative – kill grub in all stage of their life cycles

Preventative Treatments

Preventative care usually involves active ingredients such as imidacloprid, thiamethoxam, clothianidin, or chlorantraniliprole. While the name “preventative” does not sound as authoritative as curative, it is the most effective way of controlling grub.

When you apply preventative products, they only work on newly hatched grub. Therefore, you will not see its affects until months later. Usually, you’ll want to apply preventative products in late July. This will be a good time after the grub are hatched, but before they are too mature. If you apply in early spring, you risk having the pesticide move through the soil before the grubs are hatched. If you apply in August, then the grub may be too mature to be effectively controlled by the preventative product.

Preventative products, such as imidacloprid, if applied in July, will consistently reduce about 80-100% of the grubs. Remember to water immediately after application.

Tip: Remember to water immediately after application. We also recommend mowing your lawn prior to application. This will get rid of weeds and flowers that may attract bees. If there are weed or flowers that have the product on it and a bee comes by, it may end up killing the bee. We would rather not get rid of beneficial pollinators like bees.

Curative Treatments

Curative products are designed to kill grub in all life stages. However, they do not work as effectively and at any given time only kill about 20-75% of grubs. This is why at the end of the day, preventative care is still best (and needs to be performed even if you use curative products).

Curative insecticides include carbaryl and trichlorfon. Generally, carbaryl is slightly more effect on a larger variety of grubs. We suggest applying the compounds before mid-May as this is when the grubs will be feeding. If applied after mid-May, it will not be as effective.

Nematode Treatment

Nematodes are microscopic roundworms that act primarily as preventative treatment, but can also have some effects on grub later in their life cycles. Nematodes are completely natural way to eliminate grub. They also help eliminate a whole host of other insects without harming any of the beneficial insects.

The only downside? Nematodes are expensive. Very expensive. But if you have the expendable cash, we highly recommend that you try beneficial nematodes.

Tip: Nematodes are prone to dying from heat. When applying them, apply at night and with plenty of water. This will give them time to work their way into the soil before the sun beats down on the soil during the daytime. It’s also, for the same reason, preferable to apply nematodes in the springtime, if possible.

Bottom Line

We recommend that you either use preventative insecticides or curative insecticides WITH preventative insecticides. Make sure you get active ingredients that actually kill grub because there are many products on the market that do not work. If you have the expendable cash, buy nematodes as a form of treatment.  

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About the author: Carley Miller is a horticultural expert at TheGreenPinky. She previously owned a landscaping business for 25 years and worked at a local garden center for 10 years.

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