Many insects have two stages to their life. The first stage is called the larval stage. Caterpillars are in their larval stage, before becoming fully-grown butterflies. Chafer Grub is the name given to the larval stage of the chafer beetle. Before becoming chafer beetles, they are Chafer Grubs.
Chafer grubs eat the roots of the grass plants. By doing this, they promote the growth of new, healthier roots. They also form part of the soil’s ecosystem—their cases break down into the soil once they pupate (turn into beetles), adding nutrients to the soil.
We’ve seen plenty of healthy lawns that contain small populations of chafer grubs. However, just like most other parts that make up a soil’s ecosystem, too many chafer grubs can cause damage to a lawn.
In comparison to other grubs that reside in the soil of a lawn (for example, leatherjackets), chafer grubs can cause severe damage on lawns. Furthermore, the damage can be visible within a matter of days, and will get worse very quickly.
The damage is caused by two main factors:
Chafer grubs are difficult to detect until the damage has started to occur. The first signs are areas of grass starting to look yellow / brown. These areas are often mistaken for other problems such as fungal diseases or compaction.
To determine if these areas of dying grass plants is caused by chafer grubs or another lawn problem, try lifting the dead grass plants. If the grass plants lift away easily from the soil, it is most probably chafer grubs. If the plants do not lift easily and are still attached to the soil via their roots, then it is most likely a different lawn problem.
Over time, if left untreated, the affected areas will start to develop a ‘carpeting effect’ whereby the turf is easily lifted away from the soil surface. Much like carpet being lifted away from floor boards.
As the chafer grubs continue to eat the roots of the grass plants, the affected area will get bigger and bigger. In some case, an entire lawn can be decimated within a matter of days.
The above two pictures were taken just one week apart. The growth of the affected area and the destruction of this area was quick.
During mid to late summer, chafer beetles lay their eggs in your lawn. Their eggs fall onto the soil and are burrowed below the surface by rain. Over time, the eggs will hatch and become larvae.
Unlike leatherjackets, as difficult as it is, the aim is to try and eradicate chafer grubs from your lawn. They are very destructive and will continue to cause havoc unless some form of control methods are applied.
The only method available is Nematodes. Nematodes are microworms that burrow into the chafer grub and feed on them. They are widely available online.
As nematodes are living organisms, you should ensure that you store them correctly, apply them at the correct time of year and in the correct conditions. Nematodes need to be applied when the soil is warm. The soil should be kept damp during application and should remain damp for several weeks after.
We recommend that you follow the instructions included in the pack for best results.
As nematodes are living organisms, you should ensure that you store them correctly, apply them at the correct time of year and in the correct conditions. Nematodes need to be applied when the soil is warm. The soil should be kept damp during application and should remain damp for several weeks after.
We recommend that you follow the instructions included in the pack for best results.There are many factors that can affect the overall outcome of using nematodes on a lawn, so it is important that they are applied at the correct time of year and in the correct conditions. This could mean regular watering following application. The correct time of year can change depending on the weather conditions and repeat cycles are more than likely required to get the best results. The products should be used soon after purchase or kept in a fridge as they have a limited shelf life. Bearing in mind all of these factors, we would not be able to provide a cost-effective and reliable enough service.
Unfortunately, the damage caused by chafer grubs is so destructive that some form of repair will be required. This will usually be a patch repair, but in some cases, the entire lawn may need to be completed renovated.