Name the hormone which brings about metamorphosis in silk moth and changes caterpillar (larva) into adult silk moth.

The hormone responsible for metamorphosis in silk moths is ecdysone, also known as the molting hormone. This steroid hormone triggers the transformation of the caterpillar (larva) through the pupal stage and ultimately into the adult silk moth. Ecdysone works in coordination with another hormone called juvenile hormone, which must decrease for metamorphosis to proceed properly.

During metamorphosis, ecdysone initiates dramatic cellular changes including the breakdown of larval tissues and the formation of adult structures like wings, reproductive organs, and compound eyes. The silk moth's life cycle—from egg to larva to pupa to adult—is tightly regulated by these hormonal signals. This hormonal control of metamorphosis is found across many insect species, not just silk moths, and represents one of nature's most remarkable transformations. The study of these hormones has practical applications in sericulture (silk production) and pest control, where understanding insect development can improve yields or disrupt harmful species.