How Does a Caterpiller Turn into a Butterfly?

Caterpillar turning into butterfly
Share the knowledge

It is amazing that caterpillars turn into butterflies, and it is even more amazing to understand how caterpillars turn into butterflies. The caterpillar to butterfly metamorphosis is one of the great wonders of nature, so below we explain exactly how a caterpillar turns into a butterfly, going through several stages called ‘instars’, as well as situate this transformation in the larger life cycle of butterflies.

The radical metamorphosis of caterpillars came to our attention when answering a recent question by a reader. The reader asked us to identify a creature he had taken some photos of, and we tentatively concluded that he had pictures of a caterpillar turning into a butterfly. This of course required us to brush up on how caterpillars are able to mature into adult butterflies, and the fruit of this research is presented below.

As we have said many times before, caterpillars are the larval form of members of the order Lepidoptera, a large grouping that contains about 175,000 species of butterflies and moths. Like many insects, butterflies lay eggs, generally on leaves that their offspring will eat. (We’ll use “butterflies” to refer to all the members of the order Lepidoptera so we don’t have to write “butterflies and moths” every other sentence.) When the eggs hatch, caterpillars emerge and begin their relatively brief life of consuming as much food as possible. As they eat, they grow, molting several times along the way (each molting brings the caterpillar to the next instar). This is why the appearance of a caterpillar can change so much during the course of its life: it sheds off one layer of skin to assume another. Once a caterpillar has matured to the extent that nature has decreed, it will enter the third stage of its life cycle, the pupal stage, the period during which a caterpillar turns into a butterfly.

At the start of this process, the caterpillar will encase itself in a cocoon or chrysalis, both of which are outer shells of sorts that protect caterpillars as they transform into butterflies. Astonishingly, caterpillars essentially dissolve inside their casings in order to reassemble into butterflies. However, they do not entirely dissolve into a mass of identical cells, but rather retain some organizational structure through imaginal discs, which are simply collections of cells organized in a particular way. The imaginal discs actually grow when the caterpillar has yet to hatch from its egg, meaning that traces of its final adult form are part of a caterpillar before it is even born. Inside the cocoon or chrysalis, the imaginal discs grow in size by taking from the dissolved tissue that once made up the rest of the caterpillar’s body. By and by, the imaginal discs become body parts (eyes, wings, and so on) of the adult butterfly, and once the imaginal discs have taken their final form and the full transformation is complete, a butterfly emerges from the cocoon or chrysalis.

That is, in short, how a caterpillar turns into a butterfly. A caterpillar almost dissolves into nothing and then rebuilds itself – thanks to imaginal discs implanted in it since birth – into the image and likeness of a butterfly, a process that is as bizarre as it is beautiful.

 

All About Worms is always free, always reader-supported. Your tips via CashApp, Venmo, or Paypal are appreciated! Receipts will come from ISIPP Publishing.

CashApp us Square Cash app link

Venmo us Venmo link

Paypal us Paypal link

Note: Some links on this site are partner links. That means that we earn a tiny bit if you purchase something through them, at no extra charge to you. This helps offset the cost of keeping this resource free for everybody (it doesn't cover our costs, but every little bit helps! :~) )

Share the knowledge

Leave a Reply

Your email address will not be published. Required fields are marked *