Grubs in lawn? What are they?

#1 · 4th April 2023, 12:25 pm

I'm digging out my grass and occasionally finding white grubs. What are they and what should I be doing with them please? Grub

#2 · 10th April 2023, 5:11 pm

Quote from Lee Garden Ninja on 10th April 2023, 5:11 pm
Hi Helen,
Thanks for your comment. These definitely look like chafer grubs which can be a real pain for lawn enthusiasts as they feed on the roots of grass causing the following garden issues:
Damage to lawns between autumn and spring when the grubs are reaching maturity and feeding on grass roots
Patches of the lawn may become yellowish due to root damage
Birds, foxes and badgers can tear up turf in order to access the grubs to feed on them, causing shredded marks on lawns
Patches of lawn can die back or be damaged by them as they tend to be found in isolated spots.
What are chafer grubs?
A chafer grub is the larval stage of a chafer beetle, which is a type of beetle belonging to the family Scarabaeidae. Chafer grubs are commonly found in lawns and turfgrass, where they feed on the roots of plants, including grasses, causing damage to the turf. I hear from a lot of gardeners that they are finding these white grubs in their damaged lawns.
Chafer grubs are white, C-shaped larvae with brown heads and six legs. They have a plump, fleshy body with a characteristic C shape, and they can vary in size depending on the species of chafer beetle.
Chafer grubs typically have a voracious (very hungry) appetite and can cause significant damage to turfgrass by feeding on the roots, which can result in thinning, yellowing, or dead patches of grass in affected areas. This is why some gardeners dread finding them, in my experience, they are part of the life cycle of gardening, so as long as other wildlife is present, they rarely will ruin an entire lawn!
What's the life cycle of a chafer grub?
Chafer beetles, including their larval stage chafer grubs, have a life cycle that typically involves four stages: egg, larva (grub), pupa, and adult.
The adult beetles lay eggs in soil, and the eggs hatch into chafer grubs. The grubs then feed on plant roots for several weeks to several months, depending on the species and environmental conditions.
After completing their larval stage, chafer grubs pupate in the soil, and then emerge as adult beetles. The adult chafer beetles typically have a lifespan of a few weeks to a few months, during which they mate and lay eggs, starting the life cycle anew. I find that the damage to the lawn is usually isolated to late spring before they emerge as beetles.
Chafer grubs can be considered as pests in lawns and turfgrass when their populations are high and cause significant damage.
How to stop chafer grubs?
Control measures for chafer grubs may include cultural practices like proper lawn maintenance, such as regular watering and mowing, as well as biological controls like nematodes, which are highly effective when watered into the spots where grubs are first found. I'd always advocate against chemical or insecticide controls as these end up in the food chain Helen and are a bad way to be an ethical eco gardener. Which all my Garden Ninjas should aim to become! 😉
How to identify chafer grubs
Chafer grubs can be found in the soil under the loose turf. They have stout white bodies curved in a C shape, light brown heads, with three pairs of legs at the head end. They are bigger than the adult beetles and, if straightened out, can be up to 18mm (almost ¾in) long.
So I'd keep your eyes on them and see if the lawn suffers adversely. You may find there's no drama. So keep your eyes on them and if they become a problem consider nematodes!
All the best
Lee

Hi Helen,

Thanks for your comment. These definitely look like chafer grubs which can be a real pain for lawn enthusiasts as they feed on the roots of grass causing the following garden issues:

Damage to lawns between autumn and spring when the grubs are reaching maturity and feeding on grass roots
Patches of the lawn may become yellowish due to root damage
Birds, foxes and badgers can tear up turf in order to access the grubs to feed on them, causing shredded marks on lawns
Patches of lawn can die back or be damaged by them as they tend to be found in isolated spots.

What are chafer grubs?

A chafer grub is the larval stage of a chafer beetle, which is a type of beetle belonging to the family Scarabaeidae. Chafer grubs are commonly found in lawns and turfgrass, where they feed on the roots of plants, including grasses, causing damage to the turf. I hear from a lot of gardeners that they are finding these white grubs in their damaged lawns.

Chafer grubs are white, C-shaped larvae with brown heads and six legs. They have a plump, fleshy body with a characteristic C shape, and they can vary in size depending on the species of chafer beetle.

Chafer grubs typically have a voracious (very hungry) appetite and can cause significant damage to turfgrass by feeding on the roots, which can result in thinning, yellowing, or dead patches of grass in affected areas. This is why some gardeners dread finding them, in my experience, they are part of the life cycle of gardening, so as long as other wildlife is present, they rarely will ruin an entire lawn!

What's the life cycle of a chafer grub?

Chafer beetles, including their larval stage chafer grubs, have a life cycle that typically involves four stages: egg, larva (grub), pupa, and adult.

The adult beetles lay eggs in soil, and the eggs hatch into chafer grubs. The grubs then feed on plant roots for several weeks to several months, depending on the species and environmental conditions.

After completing their larval stage, chafer grubs pupate in the soil, and then emerge as adult beetles. The adult chafer beetles typically have a lifespan of a few weeks to a few months, during which they mate and lay eggs, starting the life cycle anew. I find that the damage to the lawn is usually isolated to late spring before they emerge as beetles.

Chafer grubs can be considered as pests in lawns and turfgrass when their populations are high and cause significant damage.

How to stop chafer grubs?

Control measures for chafer grubs may include cultural practices like proper lawn maintenance, such as regular watering and mowing, as well as biological controls like nematodes, which are highly effective when watered into the spots where grubs are first found. I'd always advocate against chemical or insecticide controls as these end up in the food chain Helen and are a bad way to be an ethical eco gardener. Which all my Garden Ninjas should aim to become! 😉

How to identify chafer grubs

Chafer grubs can be found in the soil under the loose turf. They have stout white bodies curved in a C shape, light brown heads, with three pairs of legs at the head end. They are bigger than the adult beetles and, if straightened out, can be up to 18mm (almost ¾in) long.

So I'd keep your eyes on them and see if the lawn suffers adversely. You may find there's no drama. So keep your eyes on them and if they become a problem consider nematodes!

All the best

Lee