Anyone who is in the rare situation of finding grubs in the garden should first determine whether it is a harmful variety. If so, there are many gentle methods of control available. For example nematodes.
Nematodes kill grubs from the inside
There is no need for chemicals against grubs
Apart from the fact that large cockchafer invasions like in the 1950s are a thing of the past and their larvae are therefore only found in moderation today - no chemical violence is necessary against the insects, which are branded as pests. The damage they and the grubs of other beetle species do is really moderate these days.
The larvae of the beetle species from the superfamily Scarabaeoidea are called grubs. However, only part of this is harmful to garden plants. This includes:
- cockchafer
- June beetle
- garden beetle
Their larvae eat roots of living plants during their 2-4 year underground development period, causing them to die. Grasses are particularly affected, i.e. the garden lawn, but also ornamental and useful plants in the bed. You can recognize the damage by the dry and wilted-looking above-ground parts of the plant, yellow islands that can be removed by hand appear in the garden lawn.
In order to eliminate the voracious grubs in the ground, it is then advisable to first dig up in the appropriate places. Just collect the larvae at first. This will not succeed completely - nematodes will help to finish off the rest as well.
Nematodes as grub exterminators
Nematodes are roundworms and form a very species-rich phylum in the animal kingdom. Some species are a serious nuisance for gardening and agriculture because they can severely damage entire arable land of crops. Others have also been discovered to be beneficial - because of their parasitic way of life.
Nematodes that can be used against grubs are primarily predatory species of the genus Heterorhabditis. They use the grubs as hosts for their reproduction. They penetrate the larvae and release deadly bacteria into their bloodstream.
However, not all grub species are equally well parasitized by nematodes. The method works quite effectively with June and garden beetles, but less well with May beetles.
Nematodes are offered in garden or hardware stores or on the Internet. The nematodes enclosed in clay granules can simply be introduced into the soil with irrigation water.