Which biological control agents are effective against white grubs?

Parasitic nematodes are effective biological control agents against white grubs because they specifically target and infect these pests. When applied to the soil where white grubs are present, these nematodes enter the grubs' bodies and release bacteria that kill the host. This natural method of pest control reduces white grub populations without the need for harmful chemical pesticides, making it an environmentally friendly option for managing these pests in turfgrass.

In contrast, while ground beetles can help control various soil insect pests, they are not specialized predators of white grubs. Ladybugs are primarily known for their effectiveness against aphids and other soft-bodied insects, and they do not typically prey on grubs. Ants, while they may interact with the soil ecosystem, do not have a significant role in controlling white grub populations. Thus, the effectiveness of parasitic nematodes makes them the correct choice for combating white grubs specifically.