Chafer grubs can be a big problem in lawns. If you see birds pecking at your lawn in large numbers or foxes and badgers digging holes overnight the chances are that you have an infestation of either chafer grubs or leatherjackets.
The chafer grub is the larvae stage of the chafer beetle. In fact there are four different beetles but it is extremely difficult to tell them apart from the grub alone. These grubs come to the top of the soil profile during warm growing months and eat the roots of the grass. Predators then scratch the grass away easily (as it has no roots) and dig to find the grubs.
Chafer grubs have thick creamy/white C shaped bodies with a light brown head capsule. They have three pairs of legs towards the head end of their body which are darker in colour than the body itself.
If possible, whilst awaiting treatment, protect the grass from predators with netting and water well in dry periods to give the grass the best chance of survival. The larvae move further down the soil profile as the soil cools and overwinter in deep soil.
There is no chemical control, however, there are biological controls which can be used and are available to purchase online.
This is the use of pathogenic nematodes which infect the pest/grub with bacteria which ultimately causes the death of the grub. These nematodes are best applied from August to October (depending upon the soil temperature and grub activity). Once purchased grubs must be kept refrigerated until you are ready to apply them.