June bugs and grubs share a close relationship in the life cycle of certain beetle species, but merely sighting one doesn’t guarantee the presence of the other—at least not right away. June bugs, also called May or June beetles, emerge as adult beetles in the spring or early summer to mate and lay eggs. These eggs subsequently hatch into grub worms, the larvae of these beetles. Grubs sustain themselves by feeding on the roots of grass and other plants, potentially causing harm to lawns and gardens.