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TED-Ed Original lessons feature the words and ideas of educators brought to life by professional animators. Are you an educator or animator interested in creating a TED-Ed original? Nominate yourself here »

Meet The Creators

  • Educator Franziska Bauer
  • Director Avi Ofer
  • Script Editor Elizabeth Cox
  • Animator Avi Ofer
  • Composer Marcos Tawil
  • Sound Designer Marcos Tawil
  • Associate Producer Elizabeth Cox
  • Content Producer Gerta Xhelo
  • Editorial Producer Alex Rosenthal
  • Narrator Addison Anderson


Additional Resources for you to Explore
For a more detailed description of the processes of metamorphosis inside the pupa, check out this site to see X-ray computed tomography images.

To find out how the fully developed—but yet not emerged—adult looks inside the pupa, visit here and here to see photos taken by the educator. You can also look at the pupae of the Scarce Swallowtail butterfly and Green Silver-lines moth. These images show that the color and transparency of the pupal cuticle is quite variable: certain photos allow you to track all body parts, while others only let you guess the wing pattern. To get a better understanding of the anatomy of the pupa, click here. And this is how the adult moth looks like after eclosion.

Eggs, caterpillars, and pupae are as varied in shape and color as adult butterflies or moths. Explore this collection of life-stage composites to get an idea of their diversity.

Parasitism in moths and butterflies refers to a process in which insect larvae, usually flies or wasps, feed inside the eggs or pupae of butterflies and moths, which eventually proves fatal.

In one example, the process of parasitism begins when the adult female wasp injects her eggs into the host eggs of the butterfly. Tiny wasp larvae then emerge from their tiny eggs inside the host. Wasp larvae, like caterpillars, also undergo complete metamorphosis. The wasp larvae feed and also pupate inside the eggs of the butterfly. Once their own metamorphosis is complete, they emerge from their host and fly away.

In this photo you can see a seemingly fresh and intact egg of a Puss moth.

Two weeks later, however, it is not a tiny caterpillar that emerges from the egg, but a group of tiny wasps.

Other parasitoid wasp larvae do not develop in the eggs of butterflies and moths, but in caterpillars. First, the wasp larvae begin to devour the caterpillar from the inside, starting with the non-essential body tissues like fat. Only very late into their development do the wasp larvae kill their host caterpillar. This is usually when they seek their way out of the host caterpillar to search for a pupation site. Check this link to see what happens when parasitoid wasp larvae leave their host caterpillar.

For a different case of parasitism in moths, have a look at the following photo. Typically, it is the developing pair of compound eyes that, due to their dark pigmentation, are first

distinguishable in a moth pupa during its metamorphosis. Sometimes, however, these eyes do not belong to the moth but to a parasitoid wasp. In this photo, it is the pupa of Heteropelma amictum, an ichneumonid wasp, that is developing in its host pupa, the Scarlet Tiger moth.

Heteropelma amictum is a common European parasitoid wasp that attaches itself to various species of tiger and owlet moths. The adult female wasp selects a host caterpillar and injects an egg into it, which does not develop until the host caterpillar pupates. The hatching wasp larva completes its larval development by devouring the interior of its host pupa. Subsequently, the wasp larva pupates and peacefully undergoes its own metamorphosis protected by the pupal cuticle of its dead host. Tracking the metamorphosis of a parasitoid wasp in its host is rarely possible, especially when their hosts form nontransparent pupal cuticles. The translucent pupal cuticle of the Scarlet Tiger moth provides the rare opportunity of observing the metamorphosis of a parasitoid wasp in its host. The wasp pupa in the photo has not developed its overall dark pigmentation yet, but its two compound eyes and three ocelli are already visible.