What chemical control metamorphosis among insects?

Metamorphosis in insects is primarily regulated by hormones, specifically ecdysteroids and juvenile hormones. Ecdysteroids, such as ecdysone, trigger the molting process and promote the transition between different life stages, while juvenile hormone helps to maintain larval characteristics and prevents premature metamorphosis. The interplay between these hormones dictates whether an insect will continue to develop as a larva or transition into a pupa and eventually emerge as an adult. This hormonal regulation allows for the complex transformation that characterizes insect development.