Butterflies begin their lives as eggs that hatch, then progress into larval stages that last a short while; during this stage they eat leaves.
Once inside, the caterpillar will form a chrysalis for up to one week before emerging and hanging with wings down, pumping hemolymph into their wings to strengthen them.
Eggs
Female butterflies begin their life cycle by laying eggs on certain plant species known as host plants, providing nourishment necessary for caterpillar development. Eggs are either spherical or ovate in shape and vary in color. Each egg is protected with chorion shell which features an inner waxy layer designed to prevent dehydration while having an opening called micropyle which allows sperm access into its center for fertilization.
Eggs laid by butterflies are attached to their host plant using an adhesive substance secreted by them, which is so strong it’s nearly impossible to separate without damaging the eggs. Depending on their species of butterfly, eggs may be laid individually or collectively at various spots on leaves or buds, usually near their top edges or at their center buds. Butterflies take care to select young, tender plants as older leaves often contain toxic compounds which could harm caterpillars once they hatch out.
Once eggs have hatched, they become larvae – the next stage in a butterfly’s life cycle. Larvae feed and grow until reaching full size before they shed their skin to prepare for pupation in order to form the hard protective outer covering called a chrysalis, in which all the parts known as butterflies begin developing inside it.
After emerging from its pupal stage, a butterfly emerges from its chrysalis with wings folded close to its body and after resting briefly it begins pumping blood into its wings and getting ready to fly away.
This lesson uses images from Twinkl Originals story The Cautious Caterpillar to teach children the life cycle of butterflies. The book can be found as an eBook, Story PowerPoint and printed book; all come equipped with additional resources including step by step worksheets where children arrange pictures depicting different stages in a butterfly’s journey, word searches and answer sheets for further study.
Caterpillar
The larva stage of a butterfly’s life cycle marks its second stage: this stage involves tiny eggs hatching into caterpillar-like creatures known as larva. At this point in development, caterpillars can crawl and feed like their adult counterparts, yet are too small to fly or reproduce yet. Chorion shells serve as protection for these caterpillars during their formative years.
Caterpillars spend much of their time feeding, and as part of the larva stage undergo some significant transformations as well. When their skin sheds several times they reveal the chrysalis – an protective shell made up of fluid-rich cells which provides nourishment while the caterpillar metamorphoses into butterflies. When caterpillars shed their skin they lose some nutrients stored inside it but this is compensated by feeding fluid provided in its chrysalis.
At its center is the chrysalis, where a caterpillar’s old body dies off as new tissues develop beneath. As its transition into a butterfly unfolds, its old body begins to disintegrate while new tissues emerge beneath. As its old skin disintegrates and new tissues form beneath, its exterior begins to look almost rotten before it emerges as something entirely different: made up of nutrients-rich fluid and highly organized groups of cells known as imaginal discs; these groupings of cells eventually transform into specific parts such as wings, eyes, legs mouthparts and genitalia of its adult form.
Once a caterpillar is ready to become a butterfly, they need to find a secure environment in which to pupate. Most moth caterpillars spin silk cocoons while most butterfly caterpillars create a chrysalis – an unusual thick flesh-like structure which starts off soft but hardens into an protective shell over time.
While the caterpillar forms its chrysalis, it cannot defecate or excrete and therefore expends vast amounts of energy and weight during this time.
As soon as a caterpillar decides it’s time to become a butterfly, they release hormones which cause its cells to dissolve – this process is known as “molting”, and occurs when their outer skin sheds for good. After this happens, its ecdysone hormones become stronger while juvenile hormones weaken; so that when this process concludes, the caterpillar grows into a butterfly instead of moth.
Pupa
The next stage in a butterfly’s life cycle is called the pupal stage or chrysalis, wherein its caterpillar undergoes complete metamorphosis to become an adult butterfly. This process occurs both with butterflies and moths; other insects that undergo this process include beetles, wasps, ants and bees as well. Prior to reaching its pupal stage however, multiple cycles of shedding and growing must take place until reaching a final pupal stage which will ensure its transformation into its adult form – another process known as complete metamorphosis occurs here before finally emerging as a butterfly!
The caterpillar stops eating while in its chrysalis, becoming protected from predators by its hard outer shell. It may spend weeks or months here depending on its species of butterfly and environment; this time provides restful preparation for its life as an adult butterfly.
At this stage, the caterpillar’s body begins to change into new tissue for wings, legs and other organs of its future form – butterfly. Additionally, this stage marks reproduction; male butterflies will mate with female butterflies; sperm will then pass from male butterfly to female butterfly to fertilize eggs that later develop into larvae.
Once a butterfly is ready to emerge from its chrysalis, it will open or “eclose” it – usually early morning but also triggered by darkness or vibrations in its surroundings.
Once they emerge from their cocoons, butterflies rest upon either their former chrysalis or some other vertical surface in order to harden their wings before flying off on their journeys.
It is interesting to observe how different caterpillars and butterflies appear; this is due to different stages in the butterfly’s life having specific purposes; eggs, larvae, pupae and adults require food sources during specific times while adults use reproduction as reproduction occurs naturally in nature. This serves as an excellent example of animals adapting their environments in order to survive; being flexible enough to adapt is key for survival in all animals.
Adult
Once a butterfly has mated with a male, she will deposit her eggs on plants that will serve as food sources when their babies hatch. A sticky substance she secretes enables the eggs to adhere securely to leaves or stems using their sticky adhesion systems; clustered egg placement may occur. While she lays her eggs she’ll also search for suitable places for pupation: by color and shape alone it usually helps her select an ideal host; otherwise she might beat on it to create scratchmarks and release an identifiable plant smell.
Once a caterpillar has eaten all its food and reached an appropriate size to protect itself from predators, it will retreat into a protective shell called a chrysalis for safekeeping. This final stage in butterfly life cycle typically takes days or months to form, during which old caterpillar body parts undergo metamorphosis to become beautiful butterfly parts which will eventually emerge from its protective cocoon when time has come.
Once the chrysalis is ready, the butterfly will create an opening in it and crawl out, its wings crumpled and damp but with enough fluid from its body pumping out that they straighten themselves out as it hangs upside down. After which it waits several hours as its wings dry out in sunlight and air.
The four stages of a butterfly’s life cycle is an endless source of fascination for children and adults alike, providing an exciting topic to explore with children who can witness this miraculous change first-hand. Twinkl Originals provides several resources that will assist with this study such as an eBook, Story PowerPoint presentation and printed book; in particular our story The Cautious Caterpillar can help introduce this important topic; simply click here for our free butterfly resource bundle!