Identifying and How to Get Rid of Grub Worm in the Lawn

While there are a lot of critters living in and on the soil, grub worm is one of the nuisance varieties.

Although it has “worm” as its name, this species is not truly a worm. What you can be sure of is that this creature may become a huge pain in your garden.

This larva typically feeds on the grassroots. It leads to damage to your lawn if there are a lot of them.

As a consequence, it is highly important to identify these critters so you will easily take what the next to do to get rid of them.


Grub Worm: Dangerous or Not

No matter what you call them, grub worms aren't actually worms at all. They are the larval life-stage of several different species of beetles in the scarab family. They are a creamy-white color with a rusty orange head and six legs at the front of their body.
Grub Worm

Some credible sources indicated that this critter is not very dangerous. It is not poisonous but you still have to be aware of it.

This larva will not bite you since it does not know how to bite.

Unfortunately, its slimy skin leads to irritation once you touch it. The symptoms may include redness, rash, and scratching.

Meanwhile, it is safe for your pets to eat this larva as long as the critter comes from sterilized soil.

However, you should note that it can be a harmful being for your lawn.

It is somehow difficult to recognize the grub worm damage on the grass when it is initially infected.

Around spring season, the sign will start to come out as your grass takes a longer time to green up.

Afterward, you will see that all your patches have died.

Grub Worms’ Identification in Brief

Lawn Grubs, often called White Grubs, are the immature form of different Scarab Beetles, such as Japanese Beetles, June "bugs" (beetles) or the European Chafers. They feed on grass roots (and organic matter in the soil), causing sections of grass in the lawn to die.
Grass Grub

This larva comes with shiny white and rusty orange color, as well as six legs at the front.

For the body, this larva has one that will curve into a C-shape and shows its yellowish-brown head.

Then, its length is about a quarter to two inches.

Grub worm has a high possibility to thrive and multiply all year in humid temperate conditions.

You can find them mostly in gardens and lawns of North America, especially Florida.

This larva is in-between stages of an adult beetle. It started with an egg and turned into a larva after hatching.

The Grub Worm Life Cycle

The life cycle of the white grub consists of 4 stages, Egg, Larvae, Pupa, and Adult. During this 4 stage process, the white grub transforms itself in shape, size, colour and feeding habits. It also changes where it lives during its life cycle.

Generally, this creature has four life cycles that complete in a year.

The one you see in the above picture is the last form, particularly the most popular adult-size of it, the June beetle.

This kind of adult beetle typically spends 2 to 3 weeks mating before laying the eggs in the soil.

Further, mostly the full-grown critters could bury around 60 eggs at once during summertime.

As the adult beetle reproduces, a new life cycle of a grub worm will start.

  • Eggs

After the beetles mate during late spring/early summer, the females lay eggs in the soil. Once the eggs hatch, the grubs feed in the soil during the warm days of summer.
Grub Worm Eggs

This is the first life cycle of the critter that usually occurs around June to August.

However, the different species will have different periods of mating that influence the period.

Meanwhile, the hatching time may vary based on several causes.

Additionally, temperature and soil wetness are two main factors that link to the next stage.

Normally, it will take two weeks for eggs of adult beetle to hatch in proper conditions.

  • Larva

During the larval stage of their lifecycle, grub worms live underneath the soil’s surface and feed on the roots of turfgrass. The roots are the primary way for turfgrass to obtain water and other nutrients.
Grub Worm Larva

The second phase, larva, is the main topic that leads to the biggest damage to your lawn.

At this stage, the egg will hatch into a larva or the so-called white grub worm.

It begins feeding on the grass-root near the surface. That is why this phase is a nuisance since your grass will truly hurt.

This larva will start getting bigger aggressively if it feeds more. You may feel safe during the winter since it will move into the soil and freeze.

However, once the spring is coming, the critter will come up to the surface and begin to feed on the roots again.

  • Pupae

The grub worm stage lasts anywhere from a few months to a few years. The grub worm then becomes a pupa (plural: pupae), and finally an adult beetle.
Grub Worm Pupa

In spring, the larva will not feed last as before the winter. It will turn into pupae that stay for a few weeks in the soil.

This stage is a point right before the final stage when the pupae will transform into a beetle.

After remaining in the soil for several weeks, the pupae will turn into adult beetle as the last stage.

This grown-up critter will crawl out of its previous location in early summer.

Grub Worm Type and How It Turns Into

There are two types of grub worms: annual grub worms that live and die within a year, and multiple year grub worms that can sometimes live for up to three years before metamorphosis.
Grub Worm Types

The life cycle of every grub worm is similar. They will pass egg, larva, and pupae stages before coming out as adult beetle.

However, the final form after pupae will be different. This nuisance larva can turn into several types of beetle as an adult.

You can spot the difference since the creatures turn into larva or as the so-called grub worms.

Their sizes become one of the indicators, but not the exact one, to know what type of larva they will turn out to be.

  1. Japanese Beetle

Japanese beetles are a serious pest of flowers, trees and shrubs, fruits and vegetables, field crops and turf.
Japanese Beetles

Popillia japonica or the Japanese Beetle has a metallic green with a shimmering copper wing covering its body.

It has tiny dark and V-shaped hairs. Its larva will grow up only up to 25.4 mm in length.

The lifetime of the Japanese beetle is short, which is around a month or up to 45 days only.

However, it can damage your lawn easily.

  1. June Beetle

June beetle, also called June bug, genus of nearly 300 species of beetles belonging to the widely distributed plant-eating subfamily Melolonthinae.
June Beetle

Phyllophaga species or June Beetle is a black-brown variety with a smaller size.

Since this type is usually found in the summer evening, people often call this creature May beetle.

This June Beetle is nocturnal and active only for a few weeks in a year. The range of life for this beetle is 1 to 3 years.

It will mostly live underground and will not cause damage as much as the Japanese beetle.

You can identify this beetle by its stubby, thick, and dark hairs.

  1. Oriental Beetle

Oriental beetles, Anomala orientalis, are about ½ inch long and are oval in top view. They range in color from solid black to mottled black and brown, to almost completely unmarked pale brown.
Oriental Beetle

Well known as oriental beetle, Anomala orientalis, syn. Exomala orientalis is Asian species that has the same size as the Japanese Beetle.

Different from the two previous beetles, the oriental beetle only feeds on flowers and skeletonized leaves.

It becomes a reason why this type rarely causes damage to your lawn.

But still, the grub worm causes injury to the root grass. It drives the lawn to become patchy and brown in fall and summer.

  1. Southern and Northern Masked Chafers

The northern masked chafer grubs usually attack cool season turf, especially if Japanese beetle grubs have been suppressed.
Southern and Northern Masked Chafers

Cyclocephala borealis and C. lurida or well-known as Southern and Northern Masked Chafers are pretty common in the northeast.

The size of this beetle is bigger than other species, which is around 25.4 to 50.8 mm. Its body is brown and shiny, whereas the head comes with a dark mask.

In late June, the adult chafers will start to breed instead of feeding. Usually, the male will just fly above the soil to find a mate.

While the Southern larva species will attack in transitional and warm-season grasses, the Northern cousins feed the cool-season turf root grasses.

Grub Worm Control: The Best Way to Get Rid of Its Nuisance

Beneficial nematodes are also used as natural grub treatment. These tiny, soil-dwelling worms release bacteria into the soil that infects and kills lawn grubs. Nematodes are available in liquid form or mixed with water and sprayed onto affected areas.
Get Rid Grub Worm

You can take basic prevention to ban the grub worms that come into your lawn.

It is better to cease all kinds of synthetic fertilizers for the lawn and switch to the natural base.

However, if you already spot any grub worm living in your lawn so the war must begin. Remove them as soon as possible.

To get rid of the worm, using a synthetic grub worm killer is something you should avoid.

It is because most of them are based on synthetic chemicals contained with neonicotinoids.

Doing so is indeed a simple way, but this will have a bad effect on the plants nearby.

Hence, the best way to get rid of grub worms is by using a natural killer.

Neem oil makes one of the best alternatives as it acquires insecticidal properties. You can even count on this solution more than a repellent.

Besides, this botanical pesticide is safe to use since it will not harm other plants nearby.

Simply mix the neem oil with water and spray the affected area for application.

Using Beneficial Nematodes

Beneficial nematodes have been shown to be as much as 96% effective against Japanese beetle grubs in field studies.
Beneficial Nematodes

Beneficial nematodes are highly effective to kill all species of grub worms.

They become the best solution without harm to others, like pets, insects, plants, soil, and even humans.

Just mix the powder-like beneficial nematodes with water.

Then, spray it over to your lawn in the evening as the time for these predators to burrow down into the ground.

Utilizing Milky Spore

When using milky spore for lawns, it can take three years to achieve control of the insect in warm climates, and even longer in cooler areas. You can also use milky spore in vegetable gardens without fear of crop damage or contamination.
Using Milky Spore

Formerly known as Bacillus popilliae, milky spore or Paenibacillus popilliae is a type of bacterium to destroy grub worm.

Although this milky spore is only effective for Japanese beetles, it will not hurt you to try the solution for other species.

However, do not expect too much of the result since it may only help that grub or beetle stay inactive instead of destroying them permanently.

In summary, if you found grub worms on your lawn, do not panic! There is a way to kill them easily.

While the shape and size of the larva might vary, the treatment might not be too different for each species.

Using the natural base pesticide or killer is way better than using the chemical-based pesticide.

This is particularly true if you want to keep your plants lively while trying to control the grub worm in the lawn.

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