Lawn worm: Identify and get Rid of Lawn worms.

Lawn worm (white grub worm or white grubs) is a garden worm that lives in the soil of lawns feeding on the roots of the grass. This garden pest has destroyed the beauty of many nice lawns in the US.

With all the discussion on forums, are giant lawn worms real? where are giant lawn worms found and identified?

What is a Lawn Worm?

Grub worms are what most people mean when they say “lawn worm”, but they are Earthworms, Dew worms and other larvae that also live in lawns.

A grub worm is the larval stage of several scarab beetles, such as June beetles, chafers, and Japanese beetles. These grubs are quite destructive to lawns as they feed on the roots of grasses.

How to Identify a Lawn Worm

lawn grub

Lawn grub worms are plump, soft-bodied creatures with a characteristic C-shape curl. For size, these larvae grow from ½ to as big as 2 inches long and have a reddish-brown head with a white or cream-colored body. They have six distinct legs.  They sometimes appear brown due to their soil habitat.

Types of lawn worms

Grubs

 These are the larvae of scarab beetles and Japanese beetles. They are white, C-shaped creatures that can grow up to an inch long. Grubs feed on the grass roots, which can cause brown patches and dead areas in your lawn.

Sod webworms

 These are the larvae of small moths. They are about ½ inch long and light brown or tan. Sod webworms feed on the blades of grass, which can cause brown patches and irregular watering. They also create silken tunnels in the thatch layer of your lawn.

Cutworms

 These are the larvae of owlet moths. They are about 1-2 inches long and can be gray, brown, or black. Cutworms feed on the stems of grass plants at night, cutting them off at the soil surface. This can cause wilting and dead patches in your lawn.

Armyworms

 These are caterpillars of moths in the family Noctuidae. They are about 1-2 inches long and can be green, brown, or black, often with stripes or markings. Armyworms feed on the blades of grass and can quickly cause large areas of lawn to turn brown and die.

Chinch bugs

 These are small, true bugs that are about 1/5 inch long and black with white markings on their wings. Chinch bugs feed on the sap of grass plants, which can cause them to turn yellow and die. Chinch bug infestations are most common in hot, dry weather.

Crane fly larvae

 These are also known as leatherjackets. They are about 1 inch long and gray or brown. Crane fly larvae feed on the roots of grass plants, which can cause brown patches and dead areas in your lawn. They are most active in cool, wet weather.

Lifecycle of a Lawn Worm

life cycle of a lawn worm - Greenbudded.com

The life cycle of a grub worm, also known as the larval stage of beetles such as June beetles or Japanese beetles, consists of four main stages: egg, larva (grub), pupa, and adult. Here’s a detailed look at each stage:

Egg Stage

  • Female beetles lay their eggs in the soil, usually in the late spring or early summer.
  • The eggs are small, white, and spherical, and are deposited a few inches below the soil surface.
  • The incubation period for the eggs is about 1 to 2 weeks, depending on environmental conditions like temperature and moisture.

Larva (Grub) Stage

  •   After hatching, the larvae/grubs, emerge and feed on the roots of grasses and other plants.
  •   Grubs are C-shaped, creamy white with a brown head, and have three pairs of legs near the head.
  •  This stage is the most destructive as the feeding grubs cause significant damage to lawns and crops by eating roots.
  •  The larval stage can last for several months to a few years going from first to third instar grubstages, depending on the beetle species and environmental conditions. During this period, grubs molt several times, growing larger with each molt.

Pupa Stage

  •  Once the larva has reached its full size, it forms a pupa in the soil, transitioning from the larval stage to the adult beetle stage.
  •  The pupal stage lasts from a few weeks to several months, depending on the species and environmental factors.
  •  During this stage, the grub undergoes metamorphosis, transforming into an adult beetle.

Adult Beetle Stage

  •  Adult beetles emerge from the soil, typically in the spring or early summer.
  •  They then mate, and the females lay eggs, starting the life cycle anew.
  •  Adult beetles live for several weeks to a few months, during which time they may feed on foliage, flowers, and fruits.

What is the Lifespan of a Lawn Grub?

The time it takes for grubs to turn into beetles varies depending on the species and environmental conditions. So, how long does it take for grubs to turn into beetles? Let’s look at the timeline for some common types of grubs:

Japanese Beetle Grubs

  • Egg Stage: 1-2 weeks.
  • Grub Stage: Approximately 10 months. They hatch in midsummer, feed on roots until late fall, overwinter deep in the soil, and then feed again in the spring before pupating.
  • Pupal Stage: A few weeks. Pupation occurs in late spring to early summer.
  • Total Time from Egg to Adult Beetle: About 1 year.

June Beetle (June Bug) Grubs

  • Egg Stage: 2-4 weeks.
  • Grub Stage: Approximately 2-3 years. Grubs feed on roots and organic matter in the soil, overwintering each year.
  • Pupal Stage: Several weeks to a couple of months. Pupation occurs in late spring to summer of the final year.
  • Total Time from Egg to Adult Beetle: 3 years.

European Chafer Grubs:

  • Egg Stage: 2-3 weeks.
  • Grub Stage: Approximately 1 year. Grubs hatch in summer, feed until fall, overwinter, and then continue feeding in spring.
  • Pupal Stage: A few weeks. Pupation occurs in late spring to early summer.
  • Total Time from Egg to Adult Beetle: About 1 year.

Lawn Worm vs Earthworm

Lawn worm vs Earthworm
Lawn Grub WormsEarthworms
C-shaped, cream-colored with a brown headLong, cylindrical, reddish-brown
0.25 to 2 inches (6 to 50 mm)3 to 8 inches (7.5 to 20 cm)
Roots of grass and plantsDecaying organic matter, soil
Causes brown patches, weakens grassGenerally beneficial, helps with soil structure

Is it Good to have Worms in your Lawn?

Although there are many disadvantages to having worms in your lawn, there are also good sides to it, these advantages are listed below;

  • Soil Aeration: Worms burrow through the soil, creating channels that allow air to circulate. This helps roots to breathe and improves the soil structure.
  • Nutrient Cycling: As worms consume organic matter, they break it down and release nutrients back into the soil in a form that plants can readily absorb. Their castings (worm poop) are rich in nutrients and act as a natural fertilizer.
  • Water Infiltration: The tunnels created by worms help water to penetrate deeper into the soil, reducing runoff and helping to maintain soil moisture levels.
  • Organic Matter Decomposition: Worms break down dead plant material and other organic matter, speeding up the decomposition process and improving soil fertility.
  • Plant Growth: The improved soil structure, aeration, and nutrient availability all contribute to healthier and more robust plant growth.

What Damage Do Lawn Worms Cause?

Root Damage

 Many lawn worms, like grubs, feed on the roots of grass plants. This can lead to weak, dying, and brown patches of grass because the roots can no longer support the above-ground parts of the plant.

Surface Damage

 Some worms, such as armyworms and cutworms, feed on the grass blades and stems above the ground. This can cause noticeable thinning and bare patches as the worms eat the grass.

Increased Bird and Animal Activity

Birds, raccoons, skunks, and other animals may dig up the lawn to feed on the worms. This digging can cause additional damage to the grass and soil.

Soil Structure Impact

 While some worm activity can be beneficial for soil aeration, excessive burrowing by certain types of worms can disrupt the soil structure, making it difficult for grass to grow properly.

Signs of Lawn Grub Damage

  • Brown Patches
  • Loose Grass
  • Presence of Grubs
  • Thinning Grass
  • Increased Animal Activity
  • Spongy Turf
  • Wilting Grass
  • Weeds Invasion

Where are Giant Lawn Worms Found

  • Australia: The Giant Gippsland earthworm (Megascolides australis) is one of the most famous giant earthworms, found in the Gippsland region of Victoria. These worms can grow to over 3 meters (about 10 feet) in length.
  • South America: In Ecuador and Brazil, some species of giant earthworms can be found, particularly in the Amazon rainforest.
  • South Africa: The Microchaetus rappi, also known as the African giant earthworm, can grow up to 6.7 meters (22 feet) long.

How to Prevent Lawn Worms

  • Proper Watering: Water deeply but infrequently to encourage deep root growth. Avoid overwatering, which can create favorable conditions for worms.
  • Aeration: Aerate your lawn to improve soil health and reduce compaction, making it less attractive to certain types of worms.
  • Mowing: Keep your grass at the recommended height for your grass type. This helps maintain strong grass that can better withstand pests.
  • Regular Monitoring: Regularly check your lawn for signs of pest activity and treat early if you notice any issues.

How do you get rid of lawn worms?

Natural Methods

  • Nematodes: Beneficial nematodes are microscopic worms that can be applied to the soil. They target and kill lawn pests like grubs.
  • Milky Spore: This is a natural bacterium that specifically targets Japanese beetle grubs. It can take a while to become effective but provides long-term control.
  • Birds and Predators: Encourage natural predators like birds to visit your lawn by providing bird feeders or bird baths.

Chemical Treatments

  • Insecticides: Use lawn insecticides that are specifically labeled for the type of worm infestation you have. Follow the instructions carefully to avoid harming beneficial insects and the environment.
  • Grub Control Products: Products containing imidacloprid or chlorantraniliprole are effective against grubs. Apply them in the late summer or early fall when grubs are young and near the soil surface.
Edet Ubok-Obong
Edet Ubok-Obong

Edet Ubok-Obong is an experienced Writer with a deep passion for Gardening, Fishing and home improvement. He shares his knowledge of these fields through this website.