What is a lifestage that many insects undergo before becoming adults?

The correct answer is larva, as this is a critical life stage for many insects that undergo complete metamorphosis, such as butterflies and beetles. During the larval stage, the insect typically appears worm-like and is focused on feeding and growing. This stage allows the insect to accumulate energy and resources that will be necessary for its transition into the next life phase.

The larva undergoes significant development as it prepares for metamorphosis, which will eventually lead to the pupal stage, where it will transform into the adult form. Understanding the larval stage is essential for pest control, as this is often when the insects are most damaging to plants, and targeting this stage can be key in managing their populations effectively.