Life Cycle of a Chafer Beetle.
During the summer months the adults can be seen flying and crawling around, you may know the beetles as May Bugs. They mate and lay eggs in the soil. The can lay an incredible number of eggs in a very short period of time. The larvae develop throughout the summer.
AUG-OCT: YOUNG GRUBS
The larvae/grubs hatch into the warm soil and start to feed and grow. While the soil is warm they stay near the surface. As the soil temperature drops they burrow further underground. It is essential to treat at this stage when they are young and near the surface and the soil is moist - perfect for nematodes.
The grubs, which have a creamy body, brownish orange head and three sets of legs near their head, are moving up through the soil as the soil temperature rises. During these months they are often deep in the soil and big, to treat with nematodes in the spring we would recommend double treatments when soil temperatures reach 12°C.
Around April the grubs enter a pre beetle stage, they become pupae and grow a hard shell. This is why we don't recommend nematode treatment in the spring, the nematodes cannot penetrate the shell of the pupae.